Advice, what parts for MFS6C hard to pull and won't start

For three winters down South we usedour brand new MFS6C on our sailboat dinghy and it worked fine. Eachyear we stored the motor with all fuel drained, including carb andfuel lines and internal tank, laid down on the tiller side, butwithout fogging the cylinder. No major issues those years.

Last year we flew down the to sailboat,in Grenada, and the outboard pulled very hard and we never got itstarted. The local mechanic also failed in 5 hours of effort. Thespark seemed good – also tried changing the plug. The are no partsin Grenada, and he has no tools. With his thumb on the plug holewhile I pulled – he thinks the compression is bad, and maybe therings have gotten in a bad way. He got a single ”pop” afteradding some heavy oil in the plug hole (he thinks it helps get one ortwo good compressions). Nothing else. He didn't have any startingfluid. Still harder to pull than normal after all this. This puzzlesme...


We gave up, stored the engine downbelow, and bought a new 3.5 HP 2-stroke, which worked great on ourdinghy all winter (although a little weaker than desired).


We're getting ready to fly back to theboat, in Puerto Rico now, and I'm looking for advice:


1 – What could be wrong with thismotor and what should we try next?
2 – What tools or parts should buyno and take down with us? Even in Puerto Rico parts may be hard toget, and although airmail packages to Puerto Rico are much cheaperthan Grenada I still lean towards having what I need and not waitingor parts...
I have bought a compression gaugeand own and have studied the Service Manual.
Should I buy the carb kit($34)? The Power Unit Gasket Set($45)? New Piston Rings ($20)?
We're pretty handy and have tools onboard. We do have one luxury of time – we can work on this motorwhile using the 3.5 HP on the dinghy. The issue is that once wecruise away from Puerto Rico to other islands parts are completelyunavailable.


Thanks for any advice! I'm seems ashame for this motor to be a complete loss...

Water pump kit would be a welcome addition,lower unit oil, a torque wrench will come in handy,patience,and bandaids. others will reply with info.

The MFS6C has decompression for easier starting, so you will not get expected readings when pull starting.
The fact that it is hard to pull is probably good compression; or it could be rust in the cylinder.
Check oil level. If too high, it could cause starting problems. If oil got in the fuel system when laid down, that will need to be flushed.
Check mechanical, electrical, and fuel systems... not necessarily in that order.
You are in warranty. What does Blue Water Marine in PR have to say?

Paul - Thanks for the response. The service manual gives a 150 psi+/-10% spec for compression without decompresor and 50psi +/-10% with decompressor - so I think this means I can still make an assessment. I have to check the warranty! If there is ust in the cylinder because I did not fog - can that be fixed? Thanks.. (By the way - would it be tough to pull if the decompressor was not working? Where exactly is that mechanism? I have the full exploded parts diagrams but I do not remember anything like this..) Thanks

Yes, a decompressor could fail, making the motor much harder to pull. If there is surface rust in the cylinder and you have pulled a lot, it is now scraped off, and the rings will need to seat again, after several hours of running. If the storage area was dry, rust isn't likely in only a few months. The decompressor is a centrifical weight on the camshaft. Once the motor is running over about 1100 RPM, the weight pulls out, and it is at full compression. At slow speeds, say 200 RPM, such as when pull starting, the weight doesn't have enough centrifical force on it to pull it away from the camshaft, and the compression is lowered.