questions on yamaha 2-stroke

[stackz]

going tomorrow to look at a boat with a 115hp yamaha two stroke.

its a C115TL engine.

what should the compression be on this engine? was there originally oil injection on this engine? owners says he pre-mixes the oil so I'm wondering if oil injection is bypassed or not.

any other issues I should focus on looking at with this engine that could be bad? water pump pee, etc

I'm obviously going to test drive the boat if the compression is good and it runs good. So I know I'll check the gear drive for grinding going from forward/reverse etc.

what should it idle at?

 

[Capt Ken]

Re: questions on yamaha 2-stroke

Compression numbers should be within 10% from highest to lowest. The C model did not have oil injection.

 

[robert graham]

Re: questions on yamaha 2-stroke

Try to find out the maintenance history on the motor, then possibly replace water pump impeller and change the lower unit oil....if these were not done fairly recently.....then you have your starting point regarding these.....learn to drain each carb float chamber once or twice a year and especially for extended lay-up periods.....it's just a brass hex-head drain screw/bolt on the bottom/side of each carb....not that hard to do and is a very good preventive maintenance item.

 

[stackz]

Re: questions on yamaha 2-stroke

ok, that dude was shady as F***. I mean seriously.

I tell him I want to do a compression test and what does he do? he cranks up the motor before I get there and warms it up. I dont ever do a compression test on warm engines with aluminum plug threads. that and my friend was there before I was (boat was at a firestone shop) and they had issues getting it cranked.

Also, the trim motor was in BAD shape, it was ballooned and the worst I've ever seen one. steering was stiff from corrosion and the motor itself was caked in corrosion. looks like the boat was just plain neglected overall.

I was there about 5 minutes before walking away. and the hunt continues!!