Yamaha 25 hp 4 stroke compression problem

[Dgallagher1)79]

Just bought a new outboard. The dealer indicated that he may be able to fix the old one and sell it on for me. Outboard was running well for about ten minutes then losing power. I had one mechanic supposedly fixed it for me by replacing the thermostat. When I took it out the same problem persisted. If I turned the outboard off it ran fine for a few minutes then power died again but outboard still ran. The dealer said this was probably the fuel pump. After examining the engine he now says that the compression in the top cylinder is low and the outboard is worth scrap value only. The first mechanic tested the compression and said is was fine. My question is if the compression is low does this indicate that tithe outboard is a write off or is the dealer chancing his arm. Nb the outboard still starts easily after one pull. He has offered me ?200. I will not sell it for this anyway as I can reuse the fuel tank and propeller for my new yamAha 25.

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[99yam40]

Re: Yamaha 25 hp 4 stroke compression problem

you can do a compression test yourself to make sure if he is correct.
Leak down test is better on a 4 stroke and will tell you more about what the problem is.