Bike not coming on the pipe

[Lethaface]

Welp fellas, for once in a long time i am truely stumped..I just finished my rebuild this weekend and went through the break in procedure..After break in i decided to shoot the bike across the yard and see how she pulls..So i started off down the yard in first but the bike will not come into the powerband at all..It just slowly builds speed and finally hits the power band right when it's about time to hit 2nd..We thought that there might be a issue with jetting so we decided to do a plug chop..So i decided to push my luck and take the bike up the street to see whats going on in the higher gears..This is where the strange thing happens..After the bike finally builds speed and hits the power band in the very last stretch of first its fine..It will go through 2nd through 6th with no problems at all and actually pulls very well..I can not figure out what the hell is going on with first gear though..The jetting seems to be perfect going through the gears with no flat spots are anything like that..A friend suggested that my gearing might be to tall with 15/40 so i dropped down to 13/40 and i'm still having the same problem..So with that said as of now i'm completly dumbfounded..The bike has ton's of compression running the 17cc domes and i was expecting somewhere between 75-80hp so it should be shredding the tires which it's not..Anyways if anybody has ever encountered something like this please share the remedy..

 

Thanks, Letha

[Rebel3190]

Well jeremy i heard that CPI's make the powerband hit later than some pipes.

[Guest nightmare]

I have the same problem if you figure it out let me know.

[Lethaface]

yeah maybe i'll come up with something.. I know it's not just late delivery of the power due to the pipes though..

[LiftdT4R]

I had a problem like that on my YZ, and it ended up being that the pilot was too lean, and the silencer needed to be re-packed. If you do re-pack it, maybe even wrap it a little looser(little more bottom end). Hope that helps, my YZ wasnt as bad as you said your shee is, but it definately didnt hit early enough(for my liking)

Edited August 15, 2006 by LiftdT4R

[shanYE west]

whats your mods and what is your jetting and elevation with what type of carbs? I had a similar problem and i turned out to be electrical (pick-up coil gap)

[r/atvshee]

i had kinda the same problem. it ran like poop then it just stalled on me. but it turned out that it was just an electrical problem

[RIPPEN]

Well jeremy i heard that CPI's make the powerband hit later than some pipes.

Mine hit like a Mac truck plenty early...

 

RIPPEN

[trex banshee]

check to make sure you aren't burning any water. My brothers shee done the same thing last year, it was just really doggy down low but once revved up alot it would pull all the way through sixth like you say. I pulled it apart and it turned out to have a very small crack and cut in the o-ring in the head.

[Lethaface]

Thanks for all the replys guys..Hopefully one of the above mentioned will work..I'm actually hopeing that it is in fact the pick up coil gapth..To awnser a few of the questions no it isn't burning water..I have a dune port on the cylinders running stock carbs so i know the motor isn't getting all the fuel/air it needs but it shouldn't be acting like it is..The mod's are as followed..

 

~Engine~

.010 over Dune ported cylinders

Hot Rods Crank

Wiseco Pro lites

CPI Inframe Drag Pipes

Paul Turner Cool Head with 17cc domes

4deg. Timing advance

TDR Reeds(for ported engines) with ported cages

Reed Spacers

White Bros Boost bottle (lol)

TORS eliminator Kit

 

~jetting~

 

Needle Clip is 2nd from the top

420 main

27.5 pilots

1800 feet elevation on stock carbs..

 

 

Anyways i'm going to get the feeler guage and go check the coil gapth..Thanks for all the replys btw fellas..

 

Letha

[yamahakid1]

ok be very careful it is your jetting. Mine was doing the same thing then it threw a rod bearing. Your main is too lean.

[Lethaface]

I appreciate your advice but it isn't the jetting.. The jetting in fact is a little on the rich side..The plug chop revealed a nice brown paper bag color..

[trex banshee]

you probably know this but just for a little more insurance, you air gap should be 18 thousandths. (.018)

[Lethaface]

Actually i thought it was .010 thousandths so thanks man

[Lethaface]

just went out and pulled the flywheel cover and think i may have found the coulpret..I could actually fit a quarter in the pick up coil gapth..I used the feeler and got it down to specs..Hopefully tommorow when i test it out again i will have some good results..Anyways thanks fellas :beer: