I just installed a new exhaust & intake gaskets, new air filter, new fuel & vent lines and a new NGK Iridium plug. Does any body think the Iridium plug could cause excessive heat in the cylinder or possible I was running to lean? Thanks!!
Blown motor
- Thread starter dlporkchop
- Start date
highly doubt the spark plug caused anything. most likely you ran lean. so when you rebuild jet it richer. did you jet it when you changed the exhaust and air filter if you didnt thats why it blew it was too lean
I didn't, a friend did. I am not sure exactly what he did. Prior to new gasket old exhaust was leaking and intake gasket was brittle. I need some 101 lessons on carbs. Thanks
I know very little about carbs. I really need to know how to re-jet one, proper jet size ie..040 over. How to check for being to lean or rich? Like I said I know very little. Thanks
easiet way to check your getting is doing a plug chop. what you do is do a wide open throttle run all the way to the top of 6th gear then pull the clutch in and shut it down pull the plug if its very white your lean if its dark and oily your rich. you want a nice brown cardboard color. jetting its not all that hard you pull the bowl off the carb and unscrew the jet and screw in a new one in its place. there are two jets the main jet and pilot jet. there is also somehting called a needle. and for idleing there is the air/fuel screw
Thanks for the info. I need to pull carb off anyway. Any sugestions on size of jet? Should pilot jet be changed or do they match up in size according to the main jet?
Hello everyone, I pulled my motor down this morning and this is what I found. The head, jug, piston, bearing and wristpin look almost new. The guy I bought it from says it was. At the top of the crankcase I noticed some irregular metal. On the exhaust side at the top was a fairly significent burr. It appears a small part of the crankcase broke off and scarred the top.I inspected all parts carefully. When I turned the piston,rings down, there was a shiny small area approx. 1/8" circle in which it appears something fell off or broke off. No other damage visible. Still doesn't explain compression loss? Any suggestions? Thanks
what are your modifacations? jetting is a royal pain and takes time. it took me over 45min to rejet last time cause it was pissin oil everywhere....... take the carb off.... open up the bowl of the carb (botom part) there will be a little goldish screw thing that you pull out and put the new jet on......... pilot jet is right beside it............. if ya need any help pm me
Re:Update Blown motor
O.K. Gentlemen. I never got my camera to post pics. Yesterday I thoughly inspected all top end patrs wiyh a magnifying glass. It takes me two type of glasses to see, must be the age thing. I could find nothing wrong with piston, rings, etc... I checked the crankcase and found no foreign objects. Clean as a whistle. So I decided what the heck put it back together. After finishing I did another compression test. It read 144 psi. So I have a Weisco .040 kit for next time. Next I checked the spark, very weak. So here I am back to the trusty forum. CDI? New plug installed.
O.K. Gentlemen. I never got my camera to post pics. Yesterday I thoughly inspected all top end patrs wiyh a magnifying glass. It takes me two type of glasses to see, must be the age thing. I could find nothing wrong with piston, rings, etc... I checked the crankcase and found no foreign objects. Clean as a whistle. So I decided what the heck put it back together. After finishing I did another compression test. It read 144 psi. So I have a Weisco .040 kit for next time. Next I checked the spark, very weak. So here I am back to the trusty forum. CDI? New plug installed.
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