Kawasaki Motorcycle Forums banner

1 - 9 of 9 Posts

·
Registered
Joined
·
110 Posts
Discussion Starter · #1 ·
Hi everyone
I have a 97 KX 250 and ever since I've owned it it fouls plugs, even when ridden quite hard but worse when just playing around. A bit of background about the bike first. When I bought it it was in need of some tlc to say the least, so I spent an awful lot getting it into a rideable condition. I got fed up with the plug fouling so I stripped the carb and found both jets to be way off standard, it was also fitted with a V-force reed block. I then changed the jets back to standard, fitted an original reed block and reeds and dropped the needle right down, it still fouls and lags a bit when the throttle is opened, it take a few secs to pick up the revs when under load. Now one dealer says to me I should try running a hotter plug, while another says it's got nothing to do with the plug and that the problem lies somwhere in the pilot jetting system. I have dropped the mix to 40 to 1 and use a new filter each time. What do you guys think I should do to get it running spot on and save me a fortune in plugs.
P.S. I am racing it for the first time next week, so please hurry..!!!:lol:
 

·
Registered
Joined
·
27 Posts
could be time for a engine rebuild ....worn parts = hokey fixes like hotter plug different and gas mixtures and changing jets ......hows your reeds look .....when was your last rebuild?
 

·
Registered
Joined
·
27 Posts
also changing your oil ratio affects your bearing....more gas less oil...duh....bye bye motor...sorry to be mean but its showing signs for help.... just my $0.02
 

·
Registered
Joined
·
110 Posts
Discussion Starter · #4 ·
It probably could do with a complete rebuild but I could only do the top end, I don't have the ability to split the cases. It runs well when really revved though and there is plenty of compression.
 

·
Knows more than he needs
Joined
·
190 Posts
maybe bad reeds? ive heard that that can simulate a very rich mixture so maybe thats whats fouling your plugs
 

·
Go green
Joined
·
9 Posts
Stock jetting tends to be a little rich. Even at sea level. Don't know your elevation but as you go up in elevation it only compounds the problem as the air density decreases. You say you've got good compression so before you go tearing the engine apart and rebuilding the top end, check the simple things first. The Spanky's Jetting Guide as posted by Tonka above is a great guide to jetting but before you go and do that I'd suggest checking your float height first. It sounds like you are getting too much fuel. 2 things typically contribute to this, those being float height (too low) and jetting too rich. When you pull your plug is it soaked in fuel? That is a common sign of float height being too low (too much fuel in the float bowl). This will cause your engine to suck in too much fuel for the amount of air it's getting. If float height is within spec or you adjust it to spec and it is still fouling plugs or lagging then I would drop a size on the pilot jet and the main jet. Also, a 40:1 mixture actually supplies more fuel then a 32:1 mixture further contributing to a rich condition. Other signs of too much fuel are spooge out your silencer running down your pipe and excess bluish white smoke out the silencer.
 

·
Registered
Joined
·
35 Posts
i had plug fouling and i realized it was bc my setting was rich. i droped the needle in my carb to 2nd setting and bam, spark plugs last me almost a year.
 
1 - 9 of 9 Posts
Top