1995 v4 carb issues??

[deathgrip4]

HI TO ALL!!!! HOPE EVERYONE IS DOING GOOD. had both of my sleds running today (1994 750, 1995 800) boy that 750 ran like a champ! not so with 800. there seems to be a bad bog at mid range it wants to die. it seems like it idles and runs at a lower rpm good, but as it picks up it seems to be starving of fuel, backfires, and bogs but if i play with throttle get it over the mid range it wants to go like hell!! last year i took apart carbs and cleaned(sled sat 4 years) replaced all fuel lines and vents.fresh gas with good old sea foam. any suggestions on were to start??also are the carb specs for the 94 the same as the 95????thanks to all,pete

[marksan]

Hello Pete,
a few questions,

Did you buy it as is?

lf you have not run it properly since buying, is there a difference in elevation between you and where it was brought?

Has it been modified?

lf the answer is yes to any of the above,and i was in your shoes, i would drop the clips on the needles one notch. Run it and do frequent plug checks. As it sounds like your midrange is indeed starved of fuel.

[deathgrip4]

bought it not running as is. was used in michigan so elevation is not a factor. only modification i know of is the clutch. what part of the carb is responsible for mid range????compression on all l 4 cylinders were within 5lbs of spec.thanks for input marksan.pete

[applecider]

I am having the same problem with a 1994 Vmax600 i recently aquired. It runs great at low and high RPM but around 5000RPM seems to be slugish. I thought it may be clutching but have ruled that out now and will be looking to the carbs as well. Perhaps a good cleaning will help. Also my plugs are a too black so I will probably drop the main jet some. I hate to think of this but I guess it could be crank seals as well.

[applecider]

The carb specs are different

[marksan]

me bad, ive amended my post, what i meant was raise the needle by droping the clip one notch.
This is a good guidlekine

www.all-offroad.com/DirtBikes/Beginners/BGNov98.html

[deathgrip4]

pulled the carbs and recleaned everything looks good only thing that caught my eye was the 4 main jets. they were all 142.5 is this ok?? im not even showing this size on the yami parts list. thanks for any help!!!

[mjdevries]

According to the spec charts on Totally Yamaha the stock jets are 143.8. Somebody else will need to pipe up on whether the 142.5 is too lean or not. Have you checked all your fuel and air lines to make sure none are loose or kinked? How about the fuel pumps? The in-tank fuel filter? Just trying to think of other things that could cause fuel flow issues.

Good luck,
Mike

[deathgrip4]

thanks mike,lines are all fine(new) fuel pumps maybe but it runs at low speeds and at top speed?? tore off reeds yesterday to take a peak inside engine 1&2 piston(clutchside) look great#3 little wear showing/light scuffing, cant feel and #4 showing wear can feel.this bothers me more. do not want to invest much more in this sled.my 94 runs great. thinking about parting out or selling entire unit. thanks again, pete

[vmax535]

142.5 mj will be fine if motor is stock and the shelf in the air box is intact.
My guess is the pilot circuit is giving you trouble. The pilot circuit consists of the fuel screw, pilot jet and air jet. Remove the pilot jet and soak in some carb/ckoke cleaner. Spray some carb cleaner into the pilot, fuel screw & air jet. When you spray it into one it should run out the other two. Contiue doing this until all passages are clear. If you can blow them out with compressed air that would help. There is a good post on Totally Yamaha describing this procedure.

www.totallyamaha.net/forums/showthread.php?t=43118&highlight=carb+cleaning

/Dan

[deathgrip4]

v max535, thanks for the reply!! I cleaned eveyrthing again looks great. need to put back together and try again.thanks,pete

[oneshotyammy]

Howdy:

You should check what "marksan" suggested if she still screws up in the mid-range as the needle jet and where it's set at controls your mid-range performance.
Good Luck,
Rob.