1987 Yamaha 130

Question
Ron, I have been trying to help a friend with his 1987 130 hp Yamaha on his Grady White 20' boat. He recently bought the boat from a relative who did had not used it for several years and very little before that. The problem is the motor will start when cold, but if you go out for a run with the boat and turn the engine off, it won't start. If you get it to higher starting rpms it sometimes starts that way, but you need to flip the choke switch to keep it running at slow speed. If you get it into gear and are able to speed it up, then it seems to run OK.
He has at this point replaced the fuel tank and had major servicing done to the engine including rebuilding the carburetors, adding a new 10 micron external fuel filter, had compression tests done which came out very well, and bottom line sunk about $2,000 with a Yamaha dealer to try to solve the problem. Last time we were at the boat, I noticed the cover of the engine was very hot to the touch, and it wasn't that warm a day. Does this sound to you like a vapor lock problemcaused by overheating? I read something that said some of the older Yamahas needed a vapor lock kit installed and that there was a Yamaha bulletin that addressed this issue, but have not been able to find it.
I'd appreciate your thoughts on this. Thanks.

Answer
Hi Bert...Thank you for selecting the undersigned to reply to your question.

I'm not a mechanic, but the symptom you've described suggests the eng. may be overheating due to a lack of water circulation. Was the impeller checked to determine if it became seized over the years from sitting so long? Is there a strong or weak stream of water exiting from beneath the powerhead? Also, there could a restriction in the cooling system, and a pressure test might give some hints toward a resolution. Have you checked to see if the block is fractured? It may need to be magna-fluxed (x-rayed).

I would take it to another mechanic who is reliable to decipher the problem.

Safe Boating
Ron

As far as not starting properly and running smoothly is concerned, it sounds like