97 Speedster- fresh rebuild- won’t start in water

[RocCityRep]

Just did a top end rebuild, rotary valve and cover on the starboard engine on my 1997 Speedster. Engine was running great at 3000 rpm on the trailer just this morning. Took it out today to start the break-in process and got it in the water and nothing. Turns over but would run. Port engine started right up and ran fine. Does this sound like a carb issue or something in the pump that is binding up with the resistance of the water? Just not sure what to try next. Any help is greatly appreciated!

 

[RocCityRep]

Just did a top end rebuild, rotary valve and cover on the starboard engine on my 1997 Speedster. Engine was running great at 3000 rpm on the trailer just this morning. Took it out today to start the break-in process and got it in the water and nothing. Turns over but would run. Port engine started right up and ran fine. Does this sound like a carb issue or something in the pump that is binding up with the resistance of the water? Just not sure what to try next. Any help is greatly appreciated!

*Turns over but wouldn’t start.

Just tried it again this morning and after a little coaxing it started back up again and finally idled back at 3000 RPM. Guess I’m going try a carb rebuild and see it that fixes it but just figured since it was idling at 3000 rpm out of the water that the carb isn’t the problem.

 

[Cable_Guy]

Maybe try some seafoam always worth a shot before take it all apart again that stuff works magic

 

[RocCityRep]

Thanks- I’ll give that a shot and report back.

 

[Cable_Guy]

have you ever had to remove the drive shaft before I have a 95 speedster and the boot on mine spinning such a pain in ass

 

[RocCityRep]

have you ever had to remove the drive shaft before I have a 95 speedster and the boot on mine spinning such a pain in ass

I haven’t personally but the previous owner of my boat did. I’ll try message him and see what he says.

 

[POPPS]

Why did you do the top end?,,,for all our seizures,,,we do an autopsy on the carbs,.(and oil pump if the carbs come clean),, the micro filters can become partially plugged, causing most seizures,

 

[RocCityRep]

The engine had low compression. Front cylinder was 110 and rear was 95 so we knew it was cooked. Amazingly it ran but sputtered and only ran at about 1000 rpm out of the water. Pistons were pretty scorched when they came out. When we had it apart we noticed some wear on the edges of the intake holes on the rotary valve cover so we had that machined by SBT and got a replacement rotary valve as well.

 

[mikidymac]

And you never rebuilt the carbs or fuel system?

And no, seafoam will not fix the fuel system on these.

 

[RocCityRep]

No- at the time we didn’t think the carbs or filter were an issue because we knew we had low compression so that was our focus. In hindsight I obviously wish we had. Rebuild kit should be here later this week so plan on doing the carb cleaning/ rebuild then.

 

[mikidymac]

Typically low compression on these is from piston seizures caused by fuel starvation.

 

[RocCityRep]

Wow- I didn’t know that! I really appreciate the advice. The fuel system/ carbs will absolutely be the next thing we do. I’ll report back.

 

[406speedster]

have you ever had to remove the drive shaft before I have a 95 speedster and the boot on mine spinning such a pain in ass

I have the 95 speedster as well. I can take the whole thing out and replace it in about an hour now. After you do it a few times it gets easier. Still a pain though, yes..cheers!