Dominic
06-29-2008, 07:13 PM
Hi. I am having trouble tuning my CMB 67 engine. I am able to get the engine running but I think it may be too rich. There is a heap of smoke coming out the exhaust. After running for a while there is a fair bit of oil in the exhaust tube.
The other reason I think it is too rich is that there seems to be fuel accumulating in the front of the boat. I think it is coming directly out of the carby instead of going into the engine. This may just be from starting though when the engine does not kick over first go. I have only really idled the engine as I don’t want to over rev it until I have the mixture right. After running for a minute or two the head of the engine remains quite cool but the exhaust is getting very hot.
I have the mixture needle set at about 1 1/4 turns out. When I rev the engine it responds instantly and revs up. It seems to rev up high than idle speed and then back down a touch. Does this mean it is actually too lean?
I am running a CMB tune pipe with the engine. The transition point is about 11 1/2 inches from the glow plug.
Any ideas would be greatly appreciated.
Thanks,
Dom
The other reason I think it is too rich is that there seems to be fuel accumulating in the front of the boat. I think it is coming directly out of the carby instead of going into the engine. This may just be from starting though when the engine does not kick over first go. I have only really idled the engine as I don’t want to over rev it until I have the mixture right. After running for a minute or two the head of the engine remains quite cool but the exhaust is getting very hot.
I have the mixture needle set at about 1 1/4 turns out. When I rev the engine it responds instantly and revs up. It seems to rev up high than idle speed and then back down a touch. Does this mean it is actually too lean?
I am running a CMB tune pipe with the engine. The transition point is about 11 1/2 inches from the glow plug.
Any ideas would be greatly appreciated.
Thanks,
Dom