I need power, advise requested

[Sootgrinder]

Hi guys, I have recently got a "new" 86 250r. and I want some advise from some of you knowledgeable folks. The cylinder is stock bore, never been ported. I have a Rad valve in it. and FMF Fatty pipe. I am very disapointed with the power output from this machine. The low to mid range power is non-existant, and the top end power is pretty okay, deffinately better than my modded 440EX but not spectacular. I have had Banshees and a Tecate in the past and they would run circles around this thing. I have played with the jetting extinsively and have settled at 150 main jet and stock pilot (I can't remember the size, I'm tired) I do not want to spend a pile of money on this thing, because it is my spare machine, but I was wondering about a larger bore sleeve in the stock cylinder, or how much would a new cylinder cost with set up for a bigger bore? Also I have heard that Hot Rods makes a drop in strocker crank for the R but then someone else said that it doesn' fit the '86. I would appreciate specific advise on parts, brands, prices and suppliers to get this thing moving out of its own way. I appologize for my ignorance but I have been away from 2 Strokers for a long time. Thanks in advance.

Chad

[barkbuster350r]

My advice would be to have someone port and polish the cylinder. And add a coolhead or have the stock head rechambered, this way you can raise the compresson for more low end power. You should be able to have this done for $300-500 and make much better power.

[86250rrider]

where do you ride? woods,sand,mx ?that would determine what mods you need. dont worry ...an r can get plenty fast! you just need a gameplan.:D

[eky_250r]

well sootgrinder, on the Hot Rod's Crank if you get the stock replacement crank you are looking at about $250 for stock. If you get the stroker crank you looking at around $300 for the crank and where it has the longer rod you will have to have some head machining for clearence. I personally have the stock replacement crank in my 250r and so far so good. I got my crank from Dennis Kirk and when I had my motor put together I had the crank and rod lighten. Just wanted to give you the heads up of the prices you are looking at for a new crank.

[86 Quad R]

you currently have a good start with the rad valve and the fmf fatty pipe but i think the stock compression is whats killing the low end.

since your not wanting to spend a bunch of money, i suggest ya stay with the oem crank and spend the money on a port job that is suited for the riding style you do the most of and bump the compression up to about 175 to 180 if ya wanting to stay with pump gas.

based on the jetting that you are currently running i assume that the quad has a stock carb. again, depending on your riding style i'd suggest that you switch to a carb oriented around the riding you do the most of. atleast a 35pwk a/s or a regular 36pwk. i like the a/s because it delivers a better bottem end power. if ya want a lil more rev then ya can always go with the 38mm series.

btw.... what generation fmf pipe are you running? the newer version isnt much to brag about as apposed to the older generation. if you are running the newer one, i'd suggest a change in pipe aswell. post a side veiw pic of the pipe if possible.

[250r4life]

i've got a buddy who bought an all orignal 86 several months ago... he went and bought an FMF pipe and silencer, put on a rad valve, and a K&N filter...

in march i rode it at the dunes, and man i was anything but impressed... in fact i thought it sucked... i dont know if it was the 86 that i didnt like, or the new FMF pipe, or a combination of them all... but it was a dog and i know that my 89 when it was stock with a pipe, and my buddies 88, woulda smoked it...

couldnt tell ya exactly, but didnt like it at all...

[86 Quad R]

Originally posted by 250r4life
i dont know if it was the 86 that i didnt like, or the new FMF pipe, or a combination of them all... couldnt tell ya exactly, but didnt like it at all...

could be alot of things that contributed to it

[86250rrider]

i myself would split the head gasket if its a three piece style first.then get a better pipe. i have a paul turner 89 race pipe for sale its banged up in the front but its waaay better than a fatty.what tooth front spocket do you have ?remove airbox lid and jet the main up about two sizes. you will have to check to be sure its correct. when i got my 86 ...it had a fatty on it ...period.i replaced to stock cage and increased compression and it woke up alot. porting makes huge power gains!!!!! my r walks away from my buddies yfz now.and it handles way smoother and feels more comfortable too.

[250r4life]

Originally posted by 86 Quad R
could be alot of things that contributed to it

oh i know... thats why i said that... i dont know why it sucked, but it sure did... the jetting was on though, i know that...

[Sootgrinder]

Thanks for all the replies so far. I ride in the steep, rocky hills of W.V. Lots of trees and steep hill climbs. The gearing is 13/39 the Fatty Pipe is 2 years old, the airbox lid has a hole cut in it and a Pre-filter bolted in over it, it looks real nice, The carb is a new stock carb, I can't justify replacing a virtually brand new carb. It looks like a port job, a bore and head mods are going to be the direction I go in. Who do you guys recommend to do the port and machine work? Thanks again, keep the good advise coming.

[86250rrider]

if your running tight stuff and nasty hills...i would go with a 12 tooth front sprocket until you get more power. your best pipe for that riding would be a paul turner type 6 . ive tried 5 pipes, and this one rocks in the woods. with this pipe and more compression and a 12 tooth front sprocket....you will be pulling very hard in all gears !! it will feel like a 400ex with a powerband:D as for porting....neil is very good.

[number5]

A cheap big horse power gain is when I went to a 295 set up. I got the sleeve atvunlimited on ebay. He doesnt list it so you got to ask for it. Just got to get it bored to 72mm. Some one on ebay is selling the 72mm pro-x piston right now for $79. I know how you feel I went from a banshee to my r that was 265 at the time and didnt think it was powerful enough.

[C-LEIGH RACING]

For the type of riding you say your doing, you need a engine with alot of compression say 200, 230 psi, thats the only thing cheap that will make it pull down low in the rpms.
With high compression though, you would need race gas after that to keep the piston cool.
Another way for bottom end pull would be the stroker crank deal, but thats not cheap & alot of engine parts would need be touched & set up for it to come out right.

The Hot Rods stroker cranks only come in the long rod version & can be used on any model bottom end be it an 86 or 89 but a cylinder spacer plate would need be used.

A big bore sleeved stock cylinder would give you more power for sure, but a few problems come along with that. The head areas the problem with trying to get a head gasket to seal good. I've ran several over the years & had the same problem each time, but its realy not that big of a deal. Getting a cool head with o ring sealing would be a fix to the problem.

With any engine build you decide on, some cylinder porting & a matched pipe would complement it all.
Neil

[Sootgrinder]

I really appreciate the help, guys. I hear several references to the "CR" head gasket. I am interested in trying it on my machine, the question is, what year CR gasket do I get? Do I have to get OEM stuff, or will the appropriate year Cometic gasket give me the thinner dimension that I am looking for. I would like to try the thinner gasket and maybe a 12T sprocket for now, and then when the motor is ready for a rebuild I will go with getting the cylinder ported. Who is Neil? and how can I get a hold of him? Well I gotta go get get the box trailer loaded up, me and my buddies are goin down to the Hatfield McCoy trails this coming weekend I got a lot of stuff to pack. Thanks again for all your help.



Chad