Maintenance & Technical > KX500 Original

she wont rev out...

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Grunty-Motor:
Need a bit of help from you guys. finally had the chance to take out my recent purchase (89 500) and after warming up, i gave it some stick  - but it gets about 1/2 way through the rev range and starts stuttering. doesnt feel electrical - more fuel. seems to have plenty of power down low and will lift in 1st/2nd.

it wont rev out in any gear. Some background;

mains - 170
second - 58
needle - middle
air - 1.5 turns out
double base gasket fitted (previous owner wanted it easier to start)
FMF fatty pipe
Tried setting float height - could understand my Clymer manual - the picture shows the point at the needle valve closing - but where do i measure?
checked the timing marks and they are at the edge of the 3 allowed marks
KIPS valves are free to move (took the little plastic cover off and it moves in and out)
standard ngk plug - brand new - so no colouring yet
reeds are fine
nothing in trans. oil
air filter clean
i'm at sea level and temp is 15-20deg.
she starts fine and idles perfect.

it really feels like there is not enough fuel - but even with a wrongly set float, wouldnt it rev out in atleast 1st?

anyone got any ideas?

Mick:

--- Quote from: Grunty-Motor on July 14, 2009, 09:18:51 AM ---it really feels like there is not enough fuel - but even with a wrongly set float, wouldnt it rev out in atleast 1st?

anyone got any ideas?
--- End quote ---
Gear selection has no impact on the float bowl, or otherwise how much fuel your motor is consuming.  All the carb knows is air velocity.  Sounds to me like  you might have more problems than you think?  It should loft the front end quite easily in 3rd and 4th as well.

It sounds to me like the reeds have hairline cracks.  I know you said they were good, but be sure to inspect them with a fine tooth comb and magnifying glass (figure of speech).  Also try a leak down compression test.  It sounds to me like you're down on power everywhere.  My '89 lost it's electrofusion plating and caused all kinds of problems.  If you catch it early it could be as transparent as a top end rebuild and replating in your case.  Aside from that go with your instincts.  If you think it's lean richen it up...see what happens.  Your jetting sounds in the ballpark by my recolection.

Grunty-Motor:
this is my first 500, so i dont have much of a bench mark - but there seems plenty power low down. it just wont rev out.

looking up the exhaust port seems to suggest piston/barrel ok (from the little i see).

reeds looked new - will have a closer look though.

anyone know the size for the flywheel puller? (or a UK Supplier)

Grunty-Motor:
can someone confirm - flywheel puller = M27x1 - left hand thread?

Jopiz:
If flywheel is made by denso im sure its m27x1 lefthanded thread. Anyways its the most common thread for flywheels. Nearly every bike from pitbikes to kx500 uses the same puller.

-J

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