[Not liking full yosh system....] - ATV Riders Forums - Honda, Yamaha, Suzuki, Kawasaki, Polaris, CanAm, Arctic Cat, Kymco ATVs

Pages:1

Not liking full yosh system....
(Click here to view the original thread with full colors/images)

Posted by: 440challenger

Got the full yosh system on my girls 400. Matched with open air box, and dynojet kit.

It seems like the yosh has all top end power. Its not crisp like an hmf or PC,sparks would be either. It actually sounds too muffled.

Anyone with the yosh have problems with lack of low end? It almost feels like i need to drop a tooth in the front.

Posted by: zrpilot

Is that a stock head pipe? If so, and your comment about being too muffled, it seems that low end performance would not be an issue.

If it is the Yosh head pipe, try temporarily taking the spark arrestor out and try that... otherwise I dunno..

Posted by: 440challenger

No its the full system...
Its jetted exactly how the DJ reccomends.
Dont get me wrong, it runs great, but i have ridden 400's with just a hmf slip on and they feel like the motor revs up faster and has much more low end power.

Posted by: Eviltanker

Check the jetting. Sometimes you may need less than the jet company recommends due to every motor is a little different.

Posted by: Pappy

I second a jetting issue. it would help if we knew what main jet you installed.

Posted by: 440challenger

It has the richest main that comes in the kit, i believe its a DJ 175
Im at sealevel and its getting colder by the day here,so i might be ok.Im going to try going one step leaner for the heck of it but.....

I still dont see how the main jet would have anything to do with how crisp the throttle responce is.. .

I believe its just the nature of the pipe. I read up on ti and it seems to be one of the more quiet pipes ,even with the arrestor removed.

Posted by: Eviltanker

Whats your elevation and average temp? Try running the equivelant of a 155-158 keihim main and a 40 pilot. you might need to back the needle of 1 notch. Like I said though it all depends on the elev and temp. Dynojet only gives a reference in there instructions to get you close.

Posted by: extremejrowe

quote:
Originally posted by 440challenger
Got the full yosh system on my girls 400. Matched with open air box, and dynojet kit.

It seems like the yosh has all top end power. Its not crisp like an hmf or PC,sparks would be either. It actually sounds too muffled.

Anyone with the yosh have problems with lack of low end? It almost feels like i need to drop a tooth in the front.

i think mine is the same .... i was wondering if that big head pipe (bigger than most) takes away bottom end and adds more topend

Posted by: atv69rider

I have to full yoshi pipe and along with 11:1 wiseco, full port and polish, 440 big bore, 450r carb, hot cams stg 2, with 16 tooth sprocket and 19 inch holeshots. I get jumped out of the hole by all the 450's then come around about 3-4 gear. if i go down a tooth 1st gear is useless so i just got used to passin people toward the end. I got everything done at once so i don't know if the pipe is a top end pipe or not

Posted by: Pappy

i think jetting is your main issue, we usually start 400ex's at a 165 and work down, ending around a 152 or 155

and i will second the 40 PJ