8hp Help

[jarape73]

Hello everyone I am new to this forum and I have already found useful stuff...well anyway here is my problem..in the past week I have become the owner of a 8hp Yamaha 2-stroke....it has been setting for awhile did a visual and all looked ok...Put the fuel to it and pulled...nothing. After awhile of checking things found nothing...I pulled the safety off of the starter pulley and put in gear so I could give it some throttle and it fired right up...shut it down due to no cooling water found it had a bad pump replaced and fired it back up let it run for awhile but would not idle pulled carb off and cleaned did find some junk in there. Put back on and the samething...there are no adj screws on the carb...Does anyone have any advice any help would be great

[rodbolt17]

why do folks get a motor and go about it all bass akwards.
folks when you get an old motor that's been sitting the procedure is test compression, test spark check gearcase oil.
if ok then rebuild the carb,rebuild replace the fuel pump and lines.
replace the water pump and t-stats and pressure control valve grommet if used.
then it starts and runs and has a chance.

the 2 stroke 8hp had an A/F needle when it left japan.

but still the compression and spark test needs to be done.

[jarape73]

I will check both...Thanks

[jarape73]

So...i found out a few more things about the motor i got....it is a 2008 8hp 2cycle...i checked compression...75/135...i know thats bad...i open up motor to find it had been in salt water alot..all cooling passages are thick in salt and build up..top piston is fubard.ring is stuck in piston......i am trying to upload pics of carb...there is no a/f screw...dont know if its worth fixing..what you think?

[TownsendsFJR1300]

Is the piston ring carboned up in the piston or is there physical damage to the piston? Hole is the top of the piston? If its just carboned up/stuck, soaking it over time will help release the ring.

How's the cylinder wall look? Any scoring?

The cooling passages can be cleaned, just some time and picking.

The cylinder wall is critical..

Oversized pistons/rings are available, of course that's a full tear down, trip to the machine shop plus parts, etc if the cyclinder is torn up..