250 Sportjet final adjustments - low idle?

[Dannon S]

Need a bit of help. Bought a new to me 2005 Utopia with the 250 Optimax M2. Ran ok for a summer then lost compression. Pulled the engine, sent the powerhead off to a known reputable machine shop. Just got everything back in the boat, chased down some wiring issues AND then a fuel suction leak. Got it started today and it sounds great but I feel the idle is too high. Cant seem to find the spec anywhere.

What should low idle be?

From what I can tell, the stops on the linkage have not been moved so I think my idle is where it should be but if anyone could verify RPM I would appreciate it.

 

[Tim75]

Need a bit of help. Bought a new to me 2005 Utopia with the 250 Optimax M2. Ran ok for a summer then lost compression. Pulled the engine, sent the powerhead off to a known reputable machine shop. Just got everything back in the boat, chased down some wiring issues AND then a fuel suction leak. Got it started today and it sounds great but I feel the idle is too high. Cant seem to find the spec anywhere.

What should low idle be?

From what I can tell, the stops on the linkage have not been moved so I think my idle is where it should be but if anyone could verify RPM I would appreciate it.

Idle RPM on the trailer should be about 1200. It will drag down to 1000-1100 in the water. Check that your control cable is not holding the throttle open.

Did you ever find out why you originally lost compression?

 

[Dannon S]

Tim75 thanks for that info! Will look at that later today. Finally got her in the water last night and started to ease thru the break in period. Runs really good now that it’s firing on all 6 cylinders the way it should. As for why it lost compression I am afraid we could not really tell. The machine shop that rebuilt it couldn’t find much wrong with it from that perspective. And he was looking for anything that might have done it.
Might have been age/hours of use? I think I was fighting a lot of issues all at once and low compression on 1&2 was just the last part. I think 1 bad coil on # 6, a bad primary fuel pump and low compression on at least 2 cylinders.

 

[Tim75]

Tim75 thanks for that info! Will look at that later today. Finally got her in the water last night and started to ease thru the break in period. Runs really good now that it’s firing on all 6 cylinders the way it should. As for why it lost compression I am afraid we could not really tell. The machine shop that rebuilt it couldn’t find much wrong with it from that perspective. And he was looking for anything that might have done it.
Might have been age/hours of use? I think I was fighting a lot of issues all at once and low compression on 1&2 was just the last part. I think 1 bad coil on # 6, a bad primary fuel pump and low compression on at least 2 cylinders.

Tim75 thanks for that info! Will look at that later today. Finally got her in the water last night and started to ease thru the break in period. Runs really good now that it’s firing on all 6 cylinders the way it should. As for why it lost compression I am afraid we could not really tell. The machine shop that rebuilt it couldn’t find much wrong with it from that perspective. And he was looking for anything that might have done it.
Might have been age/hours of use? I think I was fighting a lot of issues all at once and low compression on 1&2 was just the last part. I think 1 bad coil on # 6, a bad primary fuel pump and low compression on at least 2 cylinders.

Failed (stuck closed) injectors can kill an engine. If they are not injecting gas, they are not injecting oil either.

 

[Dannon S]

Failed (stuck closed) injectors can kill an engine. If they are not injecting gas, they are not injecting oil either.

Good info. I sent those off and had all 12 tested. All came back ok.

 

[Dannon S]

Idle is correct in the water according to the tach.
Noticed on second run that the jet cavitated a couple of times. Last time it was enough to make us get back to the dock before we got stranded. Trailered it to inspect impeller etc and didn’t see any thing. Took it right back out and it didn’t miss a beat. Thinking I might have picked up a piece of “something” as the lake is pretty littered with stuff right now.
Tim75 do you know correct part numbers or good places to get the right parts to rebuild the jet did needed? My understanding is the wear ring is NLA.

 

[cbjustDOOit]

look up

Impros stator impeller repair​

on this site

 

[chukroo]

Anyone in need of a 787 DI 2000 model. SBT engine 150 PSI in both cylinders. Comes with all accessories.

 

[Dannon S]

look up

Impros stator impeller repair​

on this site

Thanks
I will dig into that part out of season. Running good so I hate to mess that up.