Hi guys, need some advice here on what my vmax is doing. I was riding the other day when all of sudden the bike started running rough. I rode home and noticed a strong odor of gas coming out of both exhaust pipes. The carbs were synched and air fuel mixture was correct beforehand and the bike ran great. could something have hung up in the carbs? or is there a possible problem with the fuel pump or fuel pump relay? Also I thought maybe a fouled plug might be the culprit but once I checked the plugs they showed no signs of fouling and looked clean. Any suggestions?
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alorio1
Well-Known Member
Even though you checked the plugs fpr fouling(visually)thats not an indication the cylinder is firing. Start engine cold and immediatly start feeling each exhaust pipe temp by hand. If they are all firing it won't be but a few seconds before you won't be able to touch all the cylinders exhaust by touch because they will be hot. If you find one exhaust pipe just warm that will be the one not firing and could just be a bad plug. If you change the plug and cylinder is still not firing you will have to dig deeper, such as spark to that cylinder or fuel not getting into the cylinder also. But this is a quick easy check.
The only way gas can come out of the exhaust is because it didn`t burn completely, so either too much fuel (but probably not since it ran good before and carb settings don`t change themselves "suddenly") or not enough air --> blocked air filters ?, blocked "anything" that prevents air flow to the carbs?
This is rare but jets have been known to come unscrewed and fall into the float bowl. If you have spark, this might be something to check. For spark, the coil wires occasionally need snipping to provide good contact. I would verify good spark to each plug first though.
