77 9.8hp thunderbolt

sebaeo

Recruit
Joined
Aug 23, 2010
Messages
1
I have a 77 9.8hp that seems to be running on only one plug, half power. When i pull the plugs one is dry other has oil and gas, checked spark and thats good, not getting any gas? any help appreciated.
 

jbjennings

Captain
Joined
Jul 18, 2007
Messages
3,903
Re: 77 9.8hp thunderbolt

It has a single carb, so if one is getting fuel, the other should be as well. How did you check spark? Did you see how big of a gap the spark would jump, or just ground it on the block and see if it made ANY spark? If not, I'd say therein lies your problem, bad spark on one cylinder. Then again, it could another problem. Any milky looking stuff on a cylinder, or is one plug steam cleaned?
JBJ
 

ionroller

Recruit
Joined
Sep 8, 2010
Messages
3
Re: 77 9.8hp thunderbolt

mine seems to do that too..Can you only get about half throttle before it bogs out?
 
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