1988 TRX250r Overhaul

[tex250r]

Needing to trouble shoot my clutch. If theres someone that knows these clutches really well and could answer some of my questions it would really help me out.

About the clutch: the quad has been sitting for a really long time, I bought the thing under the impression that the clutch was just stuck, im starting to think thats not the problem.
I have the side cover removed and I have taken the clutch apart once already and none of the frition disks or plates seemed to be stuck. I put it all back together just like it came apart and still have the same problem. The clutch lever just pulls easy and the clutch does NOT disengage! Theres a push rod that goes through the case and applys pressure to the pressure plate. when i have it apart the push rod moves freely. It almost seems like there is something missing in between the push rod and the pressure plate. The rod doesnt engauge hard enough to free the frition disks. I have even taken the lever on the side of the engine where the cable goes to its max and its still not enought to disengauge the clutch.

Maybe someone can help me out with this question. I needing to paint my plastics on my R and was wondering it anyone knows of a good paint that will stick well to the plastic?


Any thoughts of what to do or what might be wrong? I can post pictures if it helps.

Thanks Fellas

[bigmatt61]

Paint the plastic? :huh Nooooooooooooooo! :eek2:

[cdrookie]

you're missing the little ball that goes with the rod that disengages the clutch

[hartwill]

If you have an 86-88 motor there is no place for the ball as the 86-88 motor did not come with one, that was part of the 89 upgraded clutch I believe. I had the same problem with my 86 motor. I bought it blown up and when it was assembled the clutch had no pressure I had to fabricate it to make it work. I'm wondering if ours maybe had some kind of modified clutch like the cr500 plates or something we didn't now about, this is the only conclusion I can come up with..

[eazyrider111]

I have had good luck with Krylone paint you can find it at walmart its about 5-6 bucks a can. It is really good on plastic but to make sure that it sticks really good sand down the plastics with really fine sand paper. The paint comes in many different colors so pick your flavor.

[tex250r]

Thanks for all of the replies. I wouldnt paint the plastics but they are pink! Ha this thing has the orignals and i would bet 20 bucks its been in the sun since 1988. One day when i can afford it ill get new ones.

That kinda makes sence about the bad - wrong clutch plates. Think maybe they worked for a little while and then gave out? or what would even make more sence is if the plates are too thick and theres not enough stroke in the lever to release them???

Is that kinda what your saying?

anyone know roughly what the thickness should be? I can messure them with calibers and see if what I have is way off?

[DnB_racing]

if you dont already have a service manual you should really get one... there are many online downloads for under 10 bucks, and they are really priceless to help answer questions, im not aware of any free ones at this time

[Grande Huevos]

u can go to local paint shop and get paint w special additive that adhears to plastic for 100-150 bucks or go little cheaper sand them very very very well start at like a 100 grit then 200,280 and on up to like 6 or 800. then rinse w Hot water then clean w mineral spirits then clean w dish soap and HOT water again maker sure u rinse and wipe them down completly!!! or it will crack when u paint! let dry 100% They make a Plastic paint dont remember if its krylon or dupont but wal mart has it. the cans have a little play house and chair and stuff on the front the spray paint. and u just put it on in light even coats wait about 10 min between coats, and put it on thick so when scratched it doesnt show through. I used about 4 cans on my last bike and they looked brand new!!!! couldnt even tell they were painted. although it is a process and u do have to do it about once a year depending on how much u ride but it will get u by until u can save the money for new ones and they wont be pink!!!

[hartwill]

You can go you your local automotive paint store and buy this stuff called "bulldog" it comes in a spray can, my dad owns a bodyshop and he uses it on all these new plastic bumpers he paints, it works really good. But you do have to wash it really good with dish soap and spray it right away or the oils will come back.

[tex250r]

So it sounds like whatever paint I choose to use I need to sand and then clean with hot soapy water. That's helpful. Thanks!

Anyone know how thick a friction plate should be? Or how many are there? Could I possibly have 1 set of disk to many?

Also anyone have any luck with namura pistons?

[eazyrider111]

I used to own a banshee when I worked at a shop on the central coast and the mechanic I worked with said that namura was junk. But I really dont know its all personal preference. To be honest I would go with something name brand. Stock is always good or Wiseco. Those two get my vote I have run Wiseco and never had a problem.

[tex250r]

what about sudco pistons? are they junk as well? Does anyone know if sudco pistons are cast or forged?

the cylinder has a bridged exhaust port so has anyone heard of drilling holes in the piston where the bridge is to help lube that area? I think I have read this somewhere. what are yalls thoughts?

Thanks for your time
KO

[tex250r]

Alright guess ill have to bit the bullet and buy a manual.


whats better the Clymer manual or the Honda manual?

Thx

[dhsmustang]

Don't buy one. They can be found online for free through a Google search

[DnB_racing]

Originally posted by dhsmustang
Don't buy one. They can be found online for free through a Google search really? all Ive been able to find are around 5 - 10 bucks, all the free links didnt work for me,
point him to the free links that actually work, I couldn't find any!

[dhsmustang]

try this link:

1986-1989 250R Manual (http://www.mediafire.com/?kedw7x1dzmc83bl)

[tex250r]

Man that worked perfectly! Thanks for saving me a few bucks!

[tex250r]

Question guys! So I downloaded the shop manual from above and I'm still having problems with my clutch. I need to figure exactly what motor I have. The frame says 1988 but its possible to slap a different year motor on there right? Basically there's a difference in a 88 to 89 clutch so my question is , is there a way to tell exactly what year motor I have? Something I can easily compare too?

I just need to figure this out so I can order the (missing parts) 88 and 89 are different so I don't know what to do.

Thanks for ur time.

[socal]

I have a 86 with a 88 motor in it.The 88-89 motor cases,basically the whole bottom end is black,86-87 is silver/grey!You can also look up the motor ID# online and that will tell you!

[deathman53]

250r's had different clutch push rod setups, 85-87, 88 and 89. Honda tried to get it right. 85-87 used ball bearing in the hat(inside).

here is it
http://www.servicehondapsn.com/fiche_section_detail.asp?section=161896&category=ATVs&make=HONDA&year=1988&fveh=3746

the one on the bottom is 85-87
middle is 88
top is 89(there is a part missing from that listing, it was posted on here many times) 89 also used a different pressure plate

[tex250r]

deathman53,
so if im reading this right if i have the item number 23 (retaining clip). I have a 88 motor? Ill have to tear her down again and see exactly whats there. Thanks for the help.

socal,
the motor i have does have a black lower end and a alum. topend (not painted). are 4 wheelers anything like cars? if is built in the late months of 88 they refer to them as 89s? I wouldnt think that would be the case but thought I would ask. Do you happen to know what website I could go to to run my SN on the motor.

Thanks again for your help and time

[SilverLake250R]

Here you go. Look down at the bottom of the page and you should be able to tell what year it is.

http://www.macdizzy.com/trx_specs.htm

[deathman53]

doesn't mean its a 88 motor. You can interchange all year stuff. On my 85 and 86 motors, they have a 88/89 crank and 89 clutch setup, but 85-87 cases and tranny. I have 1 88 or 89 motor. Check to see if the kicker shaft has kinda like a step in it and it lacks collar that goes over the shaft. That is the 88/89 kicker set. Now that 250r's have been messed around w/ for 25 years, alot has been swapped around to make complete motors out of ones w/ broken/worn out internals. Yes, you can run the numbers on the case, that will only tell you what model year cases they are. There is many threads about the differences and what can be interchanged in those motors.

[Pumashine]

Originally posted by deathman53
doesn't mean its a 88 motor.

The little ball, part #28 in the clutch diagram is probably missing. It is very easy to have it fall out and not know it. sounds like it happened last time someone worked on the clutch.

Same thing with the 3 small balls #27. They also get ground into nothing if the oil got low and they heated up.

Most guys spend the $80 for the 89 update kit to fix all the problems the earlier years had.

If you need the ball #28 I have a few.

[tex250r]

Man thats awesome of you! I'm not 100% sure I have the 88 setup yet. The quad is at a friends garage for the time being, with the topend tore down. He has done a bunch of rebuilds and I just wanted him to walk me through my first 2 stroke. Anyways I did look at the side of the case and its an 1988 so hopefuly the rest of the engine is just to take some cunfusion out of it.

If it is an 88 Ill need #27 if thats what Im missing? Do you happend to have any of those? Ill try and see what I have as soon as possible.




(small update)
I got all the plastics painted and the seat recoverd. Cylinder is boared and got all parts in to rebuild the top end. Just need a little time to do it. :)

[tex250r]

Going to put the top end back together in the morning. Anyone have any pointers?

[tex250r]

I got her back together :)

<a href="http://s716.photobucket.com/albums/ww170/kellyrayfireman/Mobile%20Uploads/?action=view&amp;current=IMG00291-20110515-1712.jpg" target="_blank"><img src="http://i716.photobucket.com/albums/ww170/kellyrayfireman/Mobile%20Uploads/IMG00291-20110515-1712.jpg" border="0" alt="Photobucket"></a>

Heres the old piston. Pretty beat up huh?

<a href="http://s716.photobucket.com/albums/ww170/kellyrayfireman/Mobile%20Uploads/?action=view&amp;current=IMG00292-20110515-1713.jpg" target="_blank"><img src="http://i716.photobucket.com/albums/ww170/kellyrayfireman/Mobile%20Uploads/IMG00292-20110515-1713.jpg" border="0" alt="Photobucket"></a>

I also figured out whats wrong with my clutch :) will be riding a 250r for the first time ever pretty soon.

[tex250r]

So I have the 3 ball clutch rod throw out bearing. (1988) The balls are really pointy on one end of them. Like really wore out. My question is, are both ends of the push rod suppose to be flat? The end that rides against the 3 ball is concave around the end and comes to a point in the middle. Looks like the balls cut really deep in the end of the shaft. On the other hand its really not pitted real bad and Im not sure if it comes factory a little concave?

Thanks for the help. Ill post pics of it soon

KO

[tex250r]

Heres what I think was wrong with my clutch! Anyone else seen this before?

<a href="http://s716.photobucket.com/albums/ww170/kellyrayfireman/Mobile%20Uploads/?action=view&amp;current=IMG00296-20110516-2109.jpg" target="_blank"><img src="http://i716.photobucket.com/albums/ww170/kellyrayfireman/Mobile%20Uploads/IMG00296-20110516-2109.jpg" border="0" alt="Photobucket"></a>

<a href="http://s716.photobucket.com/albums/ww170/kellyrayfireman/Mobile%20Uploads/?action=view&amp;current=IMG00298-20110516-2113.jpg" target="_blank"><img src="http://i716.photobucket.com/albums/ww170/kellyrayfireman/Mobile%20Uploads/IMG00298-20110516-2113.jpg" border="0" alt="Photobucket"></a>

[Pumashine]

Yes, it sure looks famailiar. The 3 small balls start heating up and grinding each other and the push rod. When I took it apart 3 little pieces of shrapnal fell out.

You can replace the set up with any of the three models. Most guys go with the 89 update kit available on ebay for around $80.

Here a link
http://cgi.ebay.com/ebaymotors/Honda-Clutch-Pressure-Plate-Rod-TRX250R-ATC250R-250R-/220784785031?pt=Motorcycles_Parts_Accessories&hash=item3367cc7687

[Grande Huevos]

dang that piston looks TORN UP!!!! was anything els trashed in the motor?? Let us kno how the R runs and what u think about it when u take it on the maiden voyage! Ur gonna love it!

[tex250r]

I was pretty lucky! The bottom end was in great shape! Also lucky that the piston was factory bore size and took majority of the beating. I did have to go a mm bigger so I'm sitting at 67mm. It took .040 to clean up the cylinder. What are your thoughts on rejetting the carb for that? I have rebuilt the carb but its factory jet sizes. Everything else is stock besides the new top end. Any tips?

Thanks for ur time

[Grande Huevos]

im not really sure w the 265 cylinder cuz ive always ran 310 or 330 cylinders and they ran a maine jet in the 180s. It all differs from motor to motor, there r many factors that play a role in jetting, piston size, porting, air filter, elevation, how thick the air is and so on. I would say start w pilot jet around 48-50, needle clip position in the middle and main jet somwhere in the 165-172 range? There is a thread in the "sticky" section of this forum about carb jetting/tunning that u might check out if this is ur first 2 stroke its pretty explanitory and interesting. If u still need help or have questions post a new thread here titled somthing to do w jetting ur carb or somthing and im sure u will get all kinds of people to chime in! My "tips" would b always stay on top of ur maintance!! keep ur air filter clean change oil frequently and always keep a new plug in that baby to insure a healthy strong running motor!! New plug insures good spark, clean filter insures good air flow/mixure needed to run strong, and clean oil saves crank seals and so on needed to keep compression up and keep u from rebuilding so soon! Lots of people overlook the importance of this but its on my to do list before every ride!!! I change it all approx every 5 hrs ride time its cheap, easy,and takes only a few mins to save u lots in the end!

[tex250r]

Alright gentlemen, I guess I didn't do too bad. I busted her off and it didn't fly apart. :). (I'm pumped) Here's a question for ya. She idles perfect and revs up like a champ but slap her in gear and ease out the clutch and it seems to start to load up and lose power. It smokes a WHOLE lot more when its under a load too. I did oil my main bearings with a few drops of 2 stroke oil before putting it back together and same with the wrist pin bearing. Could that be causing my problem? Could it be I mixed the gas a little too rich? I haven't had much time to mess with it yet after that. Have a 1 year old baby girl that loves her daddy. Anyways any ideas. Oh yeah like I said before its all stock except the oversize 67mm topend. Fresh carb build too with new jets.

Thanks.

[DnB_racing]

did you remove the crank? if any parts of the rings or any of the file-lings from the worn piston got on the bearings they wont last..

i just has to take a motor apart from someone not running premix, i tried to flush without removing crank, but there was no way to get all out so I took out and flushed it and it was worse then it looked like from the top..
if you suck any pieces up it will ruin your new piston and rings and bore and it could smoke.

I m going to end up getting another crank,Ive got it out and its not perfect

but did you make absolutely sure there wasn't even a spec of debris in the crank?

[tex250r]

I did not remove the crank. It looked perfect as far as debris. I'm 100% sure that it was spotless down there. I hope that's not my problem anyway. On the other hand I haven't ran this motor no more that 5 minutes yet. From what your saying wouldn't it take just a little bit of time for the debris to cause damage then start acting the way it is? I wish I had more time to trouble shoot instead of bugging everyone but family's more important.

I did put new crank seals on both sides.

Are you saying that if there was damage it would suck fuel in from around the piston and load up and smoke?

Is there a way to adjust air flow while the engine is revd up? I think there's one for the idle air?

Thanks for the help

[DnB_racing]

Originally posted by tex250r
I did not remove the crank. It looked perfect as far as debris. I'm 100% sure that it was spotless down there. I hope that's not my problem anyway. On the other hand I haven't ran this motor no more that 5 minutes yet. From what your saying wouldn't it take just a little bit of time for the debris to cause damage then start acting the way it is? I wish I had more time to trouble shoot instead of bugging everyone but family's more important.

I did put new crank seals on both sides.

Are you saying that if there was damage it would suck fuel in from around the piston and load up and smoke?

Is there a way to adjust air flow while the engine is revd up? I think there's one for the idle air?

Thanks for the help more then likely your fine! I didnt mean to worry you, I just wanted to make sure you were aware of any debris in the crank or bearings

what ratio did you mix? it doenst take too long to burn the assembly oil out, how long did you run it?

[tex250r]

I got excited about starting it and had some cheap 2 cycle oil laying around so I used it and mixed it 20:1. I know not the best idea but need to be honest here. I also don't even have a new spark plug. The old one looked ok and fired. Is there a way to increase air to fuel ratio on your carb besides just idle? I really feel retarded sometime for the things I do but man I wanted to hear her run :).

[265 sleeper]

I won't even use junk 2 stroke oil for preassembly oil . always run good 2 stroke oil .its one of those things you don't play with . Or failure is not to far . For a STOCK bike even just a over bore you should be around 162 main that's rich and a 50 pilot that's rich as well . Needle anywhere between 2nd clip from top being lean and 4th clip from top being rich. If your 0-1500 m above sea level . If your higher than that elevation you'll be really rich .

[tex250r]

Thanks for the info. Update from today:

I got some good 2 stroke oil and it didn't help anything mixing it 32:1
Would still rev up great but under load would load up and smoke (really rich)
My needle setting was in the middle.
I moved it up 2 clip slots(wanted a healthy change to see what it would do)
With the needle as low as it can go she completely change in a good way. I took off down the street and gave it the same amount of gas I have been and the front wheels came off the ground and it threw me back!! Wow she responded like a champ! I was shocked big time.

Here's my question for the day. To everyone who reads this please cast you opinion. Its a big one for me.

Engine: 67mm bore
Exhaust stock
Carb stock. 158 main jet and a 45 pilot jet
Needle setting is at the top clip (as low as the needle can get)
Mixture 32:1.
Air filter/box stock

She ran like a champ. All kinds of power. If I run the crap out of her with the above stats will I burn it up????
I'm a little confused bc I figure with the oversize bore if anything I would have to take the needle the other direction. Maybe I'm missing something here.

Thanks everyone for your time and help
Kelly O

[tex250r]

No one has an opinion?? Theres been at least 150 views since the last post.

[cdrookie]

bore size has little to do with jetting, if you went to a big bore, then a rejet would be required, but not 67mm.

nobody can say that your quad will or won't run great. can't be done. from what i'm reading it's telling me that it's too rich on the main jet. i always like keeping the needle in the middle clip and adjusting main jet size.

[tex250r]

I can understand that. Every little piece of info I can get my hands on sure helps me no matter how small. So if my clip has to be on the very top I might need a smaller main jet? Just doesn't make much since bc the motors bigger but I have to go to smaller jet then factory?

[cdrookie]

with a bigger, or fresh bore, you're sucking in more air with each stroke, so you won't need as much gas. just like when you change reeds or the whole reed block, at first you'd think to jet it fatter, but in reality you need to lean it out some.

[Grande Huevos]

Originally posted by tex250r
I can understand that. Every little piece of info I can get my hands on sure helps me no matter how small. So if my clip has to be on the very top I might need a smaller main jet? Just doesn't make much since bc the motors bigger but I have to go to smaller jet then factory?
I would highly recomend replacing the plug !! even if it looks ok and the bike is running that doesnt mean it is running to its full potential. U will b very surprised how much a new plug can wake up ur motor! Also take the bike out and run it but push the gas slowly from 1/4 throttle to full and see if u can tell how she is responding and u might get a better idea of where ur adjustments need to be made. On the same note a new plug can be helpful when tunning because u can go rip around for few min get it nice and hot then go park it and imediatley take the plug out and check the color. I kno lots of people say u have to cut the plug in half to properly check it but u can get a pretty dang good idea just by looking at it. If its black and wet then u are fat, if its white then u are WAY to LEAN!! if its its kinda a carmel color then u are prob bout right

[tex250r]

I will damn sure do that and see whats going on. Maybe the plug isnt 100 percent and thats why I have to have the clip all the way at the top.

Does aftermarket exhaust help a lot on a quad like this or is it just a little? Reason im asking is dont race this thing so I dont need very oz of power she can put out but if its a pretty big difference thats a different story :)

[tex250r]

I got to ride a little today. I did put a new plug In. Rode for a bit on each clip setting and it runs the best all the way at the top clip. (Forgot to pull the plug and look at the color) Does this mean that a bigger jet would be a waste of time and money? On the other hand the quad kinda seems to fall on her face early in the gears. I know 2 strokes are short geared but man it really short or seems that way. Is this a sign of needing a bigger jet?

Thanks.

[DnB_racing]

I didnt read all your info but did you check your compression?

[tex250r]

I have not since the new build. Do I need to? I don't have one at home but a friend has one a work I can borrow if I need to check it.

[DnB_racing]

Originally posted by tex250r
I have not since the new build. Do I need to? I don't have one at home but a friend has one a work I can borrow if I need to check it. its a good thing to do,

I always do it when I rebuild, this gives a base line to check from, and its a good indication of any wear that happens,

just to make sure its good I would borrow one it might keep you from doing any damage in case a ring didnt seat right

[tex250r]

DnB- I kicked it 3 times and it got up to 125psi. If I kicked more than that (maybe 5 times) I got like 155psi. Are these good measurements? Can I rule out any build problems?

[DnB_racing]

Originally posted by tex250r
DnB- I kicked it 3 times and it got up to 125psi. If I kicked more than that (maybe 5 times) I got like 155psi. Are these good measurements? Can I rule out any build problems? keep kicking until it doesnt rise anymore, make sure you have WOT... 155 is on the low side

[tex250r]

Oh. I didn't even touch the throttle. Let me try it again.

[tex250r]

Alright doing it that way I got 181. Maybe could have gotten a few more psi but its really hot in my garage right now. That's about where it leveled off tho. Is that good psi?

[tex250r]

Alright doing it that way I got 181. Maybe could have gotten a few more psi but its really hot in my garage right now. That's about where it leveled off tho. Is that good psi?

[DnB_racing]

Originally posted by tex250r
Alright doing it that way I got 181. Maybe could have gotten a few more psi but its really hot in my garage right now. That's about where it leveled off tho. Is that good psi? ya that's not bad.
as long as you dont have a high compression dome on, you should be good

[tex250r]

I've never heard of that so I don't guess I do. Its pretty much all factory. So what should I do with the bike only running ok with the needle at the top clip? Go to a smaller main jet?

[tex250r]

Also does anyone have a front or back brake master cylinder they would sale me? Both of mine are shot beyond rebuild.

[hartwill]

try going with a 40 or 42 pilot, make sure your air screw is 1-2 turns out if not you Will either need to go back up or down on your pilot. Check and see what needle you have and return it to middle position dgh is pretty common I prefer a CEL and get the best response from it. After this you just keep bumping up your main till its too rich at wot and then drop it back down one size. And you can fine tune with your needle clip position. This should get you pretty close to where you need to be.. when you do this make sure your air filter is clean, you have fresh gas, new plug, and your connections are tight. Also try running a non resistor plug like b8es or b9es, I always use a b9egv with great success...

Originally posted by tex250r
Thanks for the info. Update from today:

I got some good 2 stroke oil and it didn't help anything mixing it 32:1
Would still rev up great but under load would load up and smoke (really rich)
My needle setting was in the middle.
I moved it up 2 clip slots(wanted a healthy change to see what it would do)
With the needle as low as it can go she completely change in a good way. I took off down the street and gave it the same amount of gas I have been and the front wheels came off the ground and it threw me back!! Wow she responded like a champ! I was shocked big time.

Here's my question for the day. To everyone who reads this please cast you opinion. Its a big one for me.

Engine: 67mm bore
Exhaust stock
Carb stock. 158 main jet and a 45 pilot jet
Needle setting is at the top clip (as low as the needle can get)
Mixture 32:1.
Air filter/box stock

She ran like a champ. All kinds of power. If I run the crap out of her with the above stats will I burn it up????
I'm a little confused bc I figure with the oversize bore if anything I would have to take the needle the other direction. Maybe I'm missing something here.

Thanks everyone for your time and help
Kelly O

[tex250r]

Is the CEL and DGH brand names for features on the needle?? Can I pull my needle and tell what I have? Or do I need to find a old receipt and see what I bought

[hartwill]

The letters are different features, I don't remember how to read them but its length, width, and taper. Sometimes you will come across needles with numbers and letters, these are usually oem needles and iv never figured out how to read them. If yours have numbers I would replace it with one of the others I mentioned..

[tex250r]

Cool ill try it. I just ordered some bigger and smaller main jets. Ill have to order some pilot jets and wait for them to come in. I'm at 1.5 turns on my air screw. Should I adjust it until the pilot jets come in or is it not the same?

[hartwill]

Did set your air screw by finding your highest idle? Read this. It Will explain much better than I can the whole process..
http://www.miniquadsracing.com/catubydura.html

[socal]

Thanks for that hartwill...Saved that for sure!!!What I still dont get is,to lean out the carb you can lower the needle(raise the clip)downsize pilot or downsize main,and vise versa to richen the carb rite....WHERE do you start,is one more important than the other???

[hartwill]

I start with the pilot, your pilot believe it or not kinda controls everything so you want to get the idle set first but you need to follow the steps in that article on finding your highest idle. Then go to your main, and I usually start way rich and run it under load at wot, then I Will keep dropping sizes one at a time until I find it doesn't sputter any more. Last I change/ adjust my needle. For me I prefer to stick with one needle so I get consistent feedback(cel). You may find another works better for you but when I was searching for jetting info Curtis sparks suggested this needle and it has worked very well for me..

Here's the funny thing I've found about jetting. Usually the bigger the carb you would think the richer jet you need. You know if your getting more air your gonna need more fuel, right? Nope, its opposite the bigger the carb you'll use a leaner jet. Ex: I switched from 34mm pj with a 168 main and a 50 pilot to a 39mm pwk a/s and now I'm running a 160 main and 48 pilot with the same needle, on the exact same motor. This still stumps me. Can anyone explain this?

[tex250r]

I haven't had time yet to do the stuff above but I started my r the other day to let a friend hear it run. I drove down to the end of the street and turned around then hammered on it. The front tires came off the ground in first and second gear. Gained some huge power. Probably ever bit of double what she normally puts out. I was shocked. Then it died. I notice I ran out of fuel and only had what was in the bowl of my carb. Holy crap she pulled hard. I know it leaned the motor out because of the lack of fuel.


My question is does it really increase power that much or when I get my carb jetted right will it pull about that hard all the time?

Never owned a r before so sometimes I don't know what to expect

Thanks.

[hartwill]

You Will have to jet it correctly and find out... That should be incentive, lol...

[tex250r]

I finaly got to read all of the stuff about jetting in the post above. Ive been thinking about it a little bit.

This might explain some of the problems Ive been having or a least might take some cunfusion out of it.

When i first got my R i bought a cheap carb rebuild kit. New jets and new needle. I figured they would be exatly the same as what came stock. But just by looking at the needles i can see a difference in shape.

Maybe the new main jet (same size tho) and the new needle make my R run really rich. This might explain with the bigger motor it acting like it needs a smaller main jet.

Heres my question for the day. A friend gave me a K/N air filter yesterday and Im debating putting it on there. Are they good for 2 strokes? Would a K/N filter change the way she runs alot? Like maybe run good with out doing anything else to the carb? Do they make the quads run a little leaner if you dont adjust anything else?

Thanks
Have a good one

[tex250r]

Heres my question for the day. A friend gave me a K/N air filter yesterday and Im debating putting it on there. Are they good for 2 strokes? Would a K/N filter change the way she runs alot? Like maybe run good with out doing anything else to the carb? Do they make the quads run a little leaner if you dont adjust anything else?

[socal]

I personally prefer foam,the K&N will allow more airflow and you may be able to simply adjust the air screw?The K&N simply does not stop as much of the fine stuff and to me,the minimal,probably unnoticeable gains are not worth it! If you do run it,use a Outerware cover!!!

[tex250r]

Didnt think about a cover. Thanks for the reply I have a brand new foam so ill probably stick with it for a while.

[tex250r]

alright fellas, got another question

I cant yet figure out my jetting problem and thought about this the other day. Tell me if this makes sence or not. When i rebuilt my carb it did not come with the seal for the choke. It didnt look the greatest either. I went ahead and built it up anyway.

My motor still loads up at the points where the motor is pulling the hardest. Would it make sence when the motor it pulling hard, that seal could be letting some fuel by. Im not too sure how that seal truely works. Any one ever have any trouble with that seal in the past and have the same problems im having?? I have been trying to find a replacement and all i can find is the whole choke assembly.

Any help tips on if thats causing my problem?

Thanks

KO

[destey]

Originally posted by tex250r
Heres my question for the day. A friend gave me a K/N air filter yesterday and Im debating putting it on there. Are they good for 2 strokes? Would a K/N filter change the way she runs alot? Like maybe run good with out doing anything else to the carb? Do they make the quads run a little leaner if you dont adjust anything else?

The k&n style filter will let more air through the motor and should definitely rejet to accommodate. Motors like 14.7:1 air to fuel ratio, anything higher than 14.7 (like 15 or 16:1) is too lean and will overheat and cook your piston.

As you get to higher rpm and more load on the engine, its better to run closer to 12-13 to 1 ratio. This is for a couple of reasons. The extra fuel adds cooling. Also increases power as each oxygen molecule surely will be used up (oxygen being the limiting chemical reagent to how much power is produced).

Inversely, some cars use what is called lean cruise, where air:fuel ratio is 15-15.5:1. This ensures every fuel molecule is used up (maybe with a little oxygen left over). Cooling from fuel is much less as you cross over stoichiometry (perfect chemistry, everything burns, no leftover molecules).

So optimal would be your pilot jet makes 14.7:1 air to fuel, and your main jet runs a little richer than stoich (maybe 13:1). But its all guesswork with hearing+feeling how its running and looking at plug colors unless you have a wideband o2 sensor and dyno.