Tweet
I have a Yamaha 30hp 2 stroke 3 cyl that bogs from idle to about 1500-2000 rpm then, like a switch gets turned on, it kicks in and runs normal. Anyone with any ideas on this?
-
-
Probably an ignition problem, test ignition system as outlined in service manual -
It seems the cylinder or cylinders may be burning off some moisture and then it seems to run better. I believe one or more of your 3 pistons is not firing at times due to possible moisture. A common problem. check compression in each cylinder. It could be an exhaust divider plate lead and/or head gasket leak. This would draw in moisture to the piston area and foul out the plug. One good way to check for moisture is to take each plug out and one at a time thump the base of the plug onto the palm of your hand and look for the slightest indication of moisture. I think this would work best right after running and plug has cooled down enought to handle. A compression lack could indicate a problem with the crankshaft and/or piston assembly. This too could cause a simular problem. Especially a crankshaft bearing or a rod bearing that could be trying to bind.
Now I may be way out in left field but these are some serious considerations and I hope that they help. myriopod@cableone.netComment
Comment