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1991 KDX 250 Severe Engine Problems

Joined
Aug 31, 2021
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#1
Buddy of mine has a 1991 KDX 250 that used to run great. Now its having some big issues. It will not start with the kick starter even when warmed up and must be bump started. When it is running it kicks in and out of power as if it was still extremely cold and needed to be warmed up (basically constantly tugging at you). Once you do get the rpms a little ways up it just stops and bogs almost as if the main jet was clogged up. We've cleaned the carb, both jets, new air filter, new gas, new oil, checked reeds. Anyone know whats going on?
 
Likes: peterc

BSWIFT

Sponsoring Member<BR>Club Moderator
N. Texas SP
Joined
Nov 25, 1999
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#2
Your compression is likely low and a topend is your likely solution.
 

RM_guy

Moderator /
Damn Yankees
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Nov 21, 2000
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#3
Also, you say you checked the reeds. Obvious cracking is important to look for but do they completely seal when closed? There shouldn't be any light sneaking through.

The compression still sounds like the culprit though.