This is a discussion on '89 Moto 4 250 no mid or high-end power... within the Other Models/Brands forums, part of the Performance /Technical category; Ok, so I finally got he moto 4 running about two weeks ago.. turned out it needed a valve job BAD... so, I got the ...
||LinkBack||Thread Tools||Display Modes|
|06-01-2010, 06:52 AM||#1|
Join Date: Apr 2010
'89 Moto 4 250 no mid or high-end power...
Ok, so I finally got he moto 4 running about two weeks ago.. turned out it needed a valve job BAD... so, I got the thing running, new spark plug, carb is spotless... I had to hijack a piece of exhuast off of an old dirt bike (4-stroke) to use on my quad since it didn't have the header pipe when I bought it... The pipe I put on doesn't seal real good, now for my question... the bike seems to run ok on flat ground, but as soon as I start up any grade, it just loses all power. most times i have to put it in low-2 to get up slight hills... also it will not rev up past half throttle even if sitting in neutral. Could this be caused by the exhaust or do I have some other issue going on here??
Oh yeah, also I have tested compression and it's running at 153psi and the timing is dead on... Any help or suggestions will be greatly appreciated.
|06-07-2010, 03:35 PM||#2|
Join Date: Oct 2002
Sounds like a needle and seat issue. That would be the first suspect when changes in grade affect performance. Turn the gas off and pull the fuel line, pull the bowl off and see how full it is. It should be 2/3 or less.. If it is too full of fuel the carb bowl does not vent properly and can suck up extra fuel. If the bowl is nearly empty you will have to adjust the float to keep more gas in the bowl.. If you have never changed the needle and seat it is an inexpensive preventative maintenance issue if you have the carb off anyway.
01' Raptor 720, Stage 2, FCR'd
97' 250 Vitos Blaster
06' Rhino 450
94' Banshee T-5's, Vforce, ported, Cool Head, 2-1
06' Wolverine 450 - Stock!
06' LTZ 440
94' Vmax4 750, 96' 600 MountainMax
06' Vmax 1200
|Search tags for this page|
yamaha moto 4 valve adjustment,
moto 4 250 valve clearance,
yamaha moto 4 250 valve clearance,
yamaha moto 4 250,
yamaha moto4 250 valve settings,
valve clearance yamaha moto 4 250,
how to set floats in a carburetor 86 yamaha yfm 200 moto 4,
ajusting valves on moto 4 250,
1990 yamaha yfb250 moto 4 valve clearance,
yamaha moto 4 250 carburetor screws,
1991 moto 4 valve adjustment,
how to unstick a valve on a 250 yamahaw moto4 1989
Click on a term to search our sites for related topics.
|Thread||Thread Starter||Forum||Replies||Last Post|
|warrior gets no mid to high range power||drummer247||Yamaha YFM350 Raptor/Warrior ('87-Present)||15||12-03-2009 04:30 PM|
|Exhaust: Does High Power Always Cause High Decibels?||Oregon Raptor 700||Yamaha YFM700R Raptor (2006-Present)||20||01-16-2007 06:52 PM|
|not good. super high compression with vitos power pistons.||roosthrower||Yamaha YFZ350 Banshee (1987-Present)||18||01-26-2004 05:52 PM|
|High cmpression heads and power?||banshze||Yamaha YFZ350 Banshee (1987-Present)||8||01-12-2003 05:21 PM|