4 stroking unless WOT

Redbiker

New Member
Jun 21, 2014
22
0
1
Michigan
Hello everyone,
I am having an issue with what sounds to be 4 stroking. It does it while giving any throttle besides WOT. I have went down to a 60 jet so far and pin is at its leanest.. again seems to run good at WOT but also seems like I used to get better top speed than I do now. No new plug right now to do a fresh plug chop with. Plug looks tan around rim but electrode is black but not wet after ride. Looks dry and cooked a bit but not white. Just put in a new cdi and magneto to possibly fix it but it did nothing. Also changed out the exhaust pipe. Seemed to be worse after that. Any help would be appreciated at this point.
 

Larry Trotter

Active Member
Nov 26, 2017
341
152
43
74
While riding with it 4 stroking turn off the fuel and continue to run it without changing the throttle setting. If it starts running properly just before it dies then it’s running rich and if not it’s likely lean.
 
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