2002 115hp 2 Stroke Hard Starting Solved

Suachris

Recruit
Joined
Oct 13, 2015
Messages
2
Hi All,

I have a 2006 Gemini Status 5.05m RIB with a 2002 115hp 2 stroke Yamaha outboard. The motor has done less than 100 hours.

Since buying the boat second hand, cold starting's been a problem. Once running, it ran fine although smoking a lot and consuming a lot of oil.

I read heaps of posts but none of the potential solutions worked for me.

I eventually sorted it out and wanted to share what the issues were for me in case it helps others.

In staring at the engine and pulling here and pushing there, I traced a linkage from the bottom of the carburettor on the port side and found it wasn't attached to anything. I eventually worked out that it was the control rod controlling the autolube valve. The plastic end perished and split, allowing the rod to fall out.

Yamaha fortunately engineered the pump to fail open to prevent engine damage. This does however mean that at idle, the engine was getting the same amount of oil that it would get at WOT.

Replacing the clip saw a huge improvement in cold starting and oil consumption, but only when using the manual choke lever. The electric choke would only work sporadically.

Working out why the choke wasn't working became the next challenge. Pushing the key in only activated the choke at times. The wiring checked out and there didn't appear to be any other obvious issues.

As I only had one key, I wanted a duplicate key and had to pull the key from the rubber grip to get the number for the replacement key. In this process, it became clear that the key had corroded through at the eye for the key ring. This resulted in the key sliding back into the rubber grip, giving the impression that it was moving into the lock and activating the choke.

A new key solved that issue.

Starting the engine now was a case of lowering it; I found that priming it if the engine isn't lowered makes it almost impossible to start; priming, fast idle lever up, pushing in the key to activate the choke and spinning it for 5 to 10 seconds and it would start every time.

That lasted for most of last season, until the electric choke stopped working again. This time it was a small rubber grommet at the bottom of the choke solenoid mounting that had perished and split. As the choke rod runs through the metal housing, the absence of the grommet made it bind and the electric choke wouldn't operate. A new grommet and some lubricant sorted that out.

Now it is back to lower, prime, fast idle up, choke, spin and run.

I hope this information may help others with similar problems.
 

Fi6jam

Recruit
Joined
May 24, 2022
Messages
1
Thank you very much for sharing your adventure.
I have the same engine, and have the same start problem.
Found the same problem with the rubber grommet. Fell apart in my fingers.
And have made a similar mistake of priming the fuel before lowering the engine.
I’m going out on Friday and keen to try the start procedure you’ve suggested. I feel I’m over thinking it and trying to hard to speed the boat ramp process up. A couple of seconds to prime the gas, is nothing.
Cheers from New Zealand. :)
 

boscoe99

Lieutenant Commander
Joined
Aug 22, 2013
Messages
1,785
Great report. The oil control rod retainer and the choke link retainer I knew about. The corroded key failing to activate the choke switch resulted in an epiphany. Would never have thought of that in a million years.
 
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