off jetting

[mrcbr76]

I picked up 250r last fall as my first quad. It ran fine in the fall and spring. Summer came along and it won't start.

I pulled the carb for a cleaning and found the jetting was at 155 for main / 42 for the pilot. I thought this was a little odd since stock is 150 main / 48 Pilot.

As far as I know here is the setup.
1986 TRX
bills pipe - dg silencer
BR8 iriduim plug
30 over
stock keihn carb
closed airbox with Uni filter
New stator
Jannsen Supercoil
stock CDI

Also, when I went to clean the carb I noticed the Air Screw was 1 turn out...? I cleaned everthing put back togather and put the air screw at 2 turns... it fired up, ran for 30 seconds then died.

It seems odd to me that the pilot jet is smaller thank stock and I suspect it the problem for me. Can anyone confirm this, and suggest a better "starting point" for me with a Pilot in order to get going and get it dialed in?

Thanks.

[RyanWsly]

Pipe scavenges more possibly, leaner may be what it needs. I have a 42 pilot in mine, it's a short rod, calls for 48 as well, but that's where mine is right now, doubt this is your problem. We need more details, is it sparking? flooding gas? things like that. 42 pilot is stock for 89 and maybe 88, should be close enough to run. check and make sure your pilot jet is clear, not stopped up if your worried about it, that would be the problem with it. main jet seems a bit lean to me, but like I said you just have to see what it wants.

[1promodfan]

Yea, just like Ryan said.......a 42 pilot is not necessarily small. Thats what I run in my bike. I have a 310 cylinder, boyeson reeds, 36 quadvent PWK......etc.

[250r grave yard]

take the lid off that should help

between the years they changed jetting ,stroke , porting design , spark plug temp ( br9es 86-87 /br8es 88-89 ) and piston height

i always ran a br8es and had perfect plug color in my 265r , 38mm airstriker , paul tuner wana be pipe , my own all aroud porting on 88-89 cylinder , long rod crank 88-89 , 86 style piston , advanced timing , 158 main , and 42 pilot oh yea compression at 175 psi and ran half and half

[mrcbr76]

Update

Here is the rest of the info, it is an 1986 and also has a Jannsen Supercoil which looks pretty new and what I assume is the original CDI.

Originally when it stopped running I determined my spark was not as strong as I figured it should have been and pulled the stator cover to find a puddle and moisture. I picked up a new stator and threw it on, but no change.

Per the suggestions above I cleaned the carb again (including the pilot which was clean), checked the float and put it back on. I drianed the remaining gas and threw in some fresh stuff. I pulled the airbox lid and had the same result... it sputtered but would not start. Afterward, after I kept kicking ther was no attempt to fire by the motor. My plug is gapped right, even a slight on the tight side per other postings.

[86 Quad R]

have you tried a different coil or cdi? and have checked the ground connections as well as the harness connections?

do you have a repair manual? if not, get one. they are helpful when it comes to such issues as what your having.

[dynofox]

Sure you are getting a good flow of fuel from the tank (plugged petcock)? You have tried a new plug correct? Tried pouring a little pre-mix into the spark plug hole and the tried re-starting? Tried pop starting it? Done a compression test?

[86 Quad R]

Originally posted by dynofox
Sure you are getting a good flow of fuel from the tank (plugged petcock)? You have tried a new plug correct? Tried pouring a little pre-mix into the spark plug hole and the tried re-starting? Tried pop starting it? Done a compression test?

i'd not recommend that. :huh

[250r grave yard]

check your pulse generater pick up check your flywheel check your connections from the stator to cdi .

flywheel can lose its charge or the pickup piece on the flywheeel can be damaged or to far from pulse generater pickup

pulse generater pickup could be to far from flywheel can be brokin or got fried when the moisture hit it

i would try pouring so pre-mix into the cylinder to see if it runs if it does run for a sec you know its your carb .

your carb could have a leak between the carb and reeds and that would cause your bike to not start or rev like crazy no kill swicth wil stop it put it in gear and hold the brake and let the clutch go

oh yea ima go get my manuel today to check but if you test your cdi pulse generater coil or stator with a ohmn meter every thing i think is between 50-200 ohmns for a good running electrical part

[dynofox]

Originally posted by 86 Quad R
i'd not recommend that. :huh

Why not? If he has spark and its getting fuel it is worth a try.

[86 Quad R]

Originally posted by dynofox
Why not? If he has spark and its getting fuel it is worth a try.


it hasnt been confirmed that its getting fuel.

[dynofox]

Originally posted by 86 Quad R
it hasnt been confirmed that its getting fuel.

That was one of the questions I asked him, whether or not he knew if fuel poured out of the fuel line like it should or if he needs to remove and clean the petcock. Of course you would want to be sure it had spark and was getting fuel before trying to pop start it, if not whats the point? I'd even suggest a little pre-mix down the spark plug hole while doing this. Its hard to believe he wouldn't have checked to see if it was getting fuel before typing his original post but you know what they say about assuming....:D

[mrcbr76]

I had checked the wiring before including the ground. They were ok, I cleaned and put in dielectric grease on the connections.

I'm going to check the fuel flow (petcock) first. It's a new stator and pickup so I hope it's not the pickup.

If fuel is ok I'm going to put some into the cylinder to see what happens. I don't have a compression tester but it's on the short list of items to procure.

I'm not going to try the pop start, I've seen 86 Quad R comments before advising against it! Last thing I need is to fix additional issues right now.

Thanks for the tips/comments. I'll update after the weekend once I get a chance to get away from the wife and kids and work on it more.

[mxduner]

Originally posted by mrcbr76
it sputtered but would not start. Afterward, after I kept kicking ther was no attempt to fire by the motor. i have seen this problem with my r and my other quad 250x, it was a bad cdi box. can you borrow a known good one from somebody?

[RyanWsly]

Check your connections where the stator harness and main harness go together, little round push in *******s come loose, won't stay tight, mine mysteriously did that before, couldn't find it easily because the rubber was holding it together. If you need a CDI to test it with, I have one that will make it start, but will run like ***, your more then welcome to it if you want to pay to have it shipped to ya.

[250r grave yard]

foundmybook 1986 1987 1988 1989


below 5000ft #150 #152 #158 #155
3300-6600ft #148 #150 #155 #152
above5000ft #145 #148 #152 #150
slow jet #48 #48 #45 #42

1986 &1989 call for a br8es 1987 & 1988 call for br9es


the ingnition timing also changed in the years of the 250r 1986-1987 is 19 degrees BTDC and 1988-1989 21 degrees BTDC

now for the how to check ur pulse generator , exciter coil , and the stator

to check the exciter coil dis connect the black/red wire leading to the stator and put one on the black/red wire and the other the on ground/frame . the ohms should be anywhere from 50-250 ohms

to check pulse generator disconnect the blue/yellow and green/white wire .then connect the leads to the 2 wires and should get back 50-200 ohms

to check stator detach black/yellow and green wire from stator . Disconnect high tension lead (coil wire) from spark plug .To check primary winding resistance , attach one ohm meter lead to black/yellow wire on stator and the other lead to green wire .Should read 0.1-0.3 ohms . Perform 2 secondary winding tests ,one with spark plug cap attached to coil wire and one without spark plug cap attached . Attach one lead to spark cap and other lead to the ground (green wire ) .Secondary winding test trhough cap should be 7k-11k ohms . Then attach the lead to high tension wire and the other lead to the coil ground . Should read 3k-5k . hope this helps you out

check your compression had that problem with my blaster when i first started workin it i could get it to fire but wouldnt run for long. the compression kit is only 30 bucks get it at any auto store . when you check it check it with wide open throttle and should get a good reading with 4-6 kicks should be 110 -130 for a stock piston and head

[mrcbr76]

Thanks, I now have a laundry list of items to run through this weekend!

[250r grave yard]

let me know if you need anything else good luck

[mrcbr76]

I went through the electronic stuff etc. and it gave a bad reading for the coil. My (bad) assumption was that this was the last possible thing that could be a problem since it was the newest part on the quad whe I bought it. The spark was there, but not as great as I guess it should have been. So I picked up a new Janssen coil and put it on, it has a brighter spark. But... still no start. It fires better but still does not run good and then dies. when I pull the plug it's soaked in fuel. So my ignorant question to the experienced people is... is this my reeds? Or am I jetted way to rich?

Also, seems a few people are pointing to the CDI. From what I see in the manual (I finally got one of those!) they can't be tested. I might as well pick on up and try it out. Then I'll know it's not electrical since I have a new coil and stator already.

As usual all tips and comments are greatly appreciated!

[Saul76]

Originally posted by mrcbr76 So I picked up a new Janssen coil and put it on, it has a brighter spark.

Not to thread hi-jack - but - anyone else have one of these and think they are a good upgrade?

[RyanWsly]

Check the float height, or try starting it with the petcock off, turn the gas on to make sure the bowl is full, turn it back off, may take a few kicks, but if the float is flooding it this should take it out of the picture, wouldn't rule it out if it doesn't work though. Take out the reed cage, check to see if the reeds are hanging open, weak or broken, weak or broken must be replaced, hanging open, try flipping them and see if it corrects your problem, and yes bad reeds will make a very rich mixture.

[mrcbr76]

UGH.... so I stand here with my tail between my legs. In checking and double checking the float height due to excessive fuel to the cylinder I also checked the reeds. And there it was broken reed.

I'm so PO'd at myself for not checing a month ago.

Thanks everyone for help and tips. Either way my electrical has been redone, soldered, and dielectric greased. Also, I had a good chance to clean various nooks and crannies.