2000 Optimax 225 starts & Stalls

[MadMat]

Hi all (22 years!! a member here - are any of the old crowd still around?)

I have a 2000 Optimax 225 (early model). Generally runs well except for 1 issue.
From a cold start it will fire right up, but then as it settles back down to 550 rpm, it'll stall.
It also occasionally stalls when it's been idling for a while when warm, sometimes on it's own, sometimes when I shift in to gear.
Once it's done this, to get it to restart, it needs bit of throttle and then I need to hold the idle at 1000-1200rpm for a bit - then it'll idle back down to 550 rpm quite comfortably again.

It has new plugs & fresh fuel.

I've not yet checked the air and fuel pressures, I'll do this next, but in the meantime, I wondered if this was a common symptom of anything specific, one of the regulators splitting, worn air compressor etc.

Thank you
Matt

[XstreamVking]

I have found that if you have good fire from the coils and good plugs the next thing is the compressor air/fuel rail system. I had my 225 opti behave poorly at idle. The rubber diaphrams were good but the springs had weakened and corroded, The hi pressure one even broke. If you have original fuel rail parts, and a hi hour compressor, I would start there. Careful on the air reg. it has 80 lbs of pressure.

[MadMat]

Thanks. Yeah, I have a tracker diaphragm on order "just in case", this this seems to be a common one. Will plug gauges into the air and fuel rails next time I'm at the boat.

[282]

I had that with my 2011 300 opti- it was an easy fix and a common issue from what I was told. But..... I do have to say my motor was a pain in the ass, low hours but always something-everything was a simple fix but I ran out of confidence in that motor

[XstreamVking]

I have to say that my opti's (4 of them) are just as trustworthy as my other 2 strokes. You DO have to be vigilant of the fuel/air system and keep everything in good shape. Simple tests for the fuel rail, compressors health do that. Most of my original rubber diaphrams were still good, I just figure it's smart to replace 15 y/o rubber parts. My opti's still do better mpg's than my buds 4 strokes. Better out of the hole, and just as good or better on the top.