Loss of Top RPM

[Dheimbuch]

What may cause a loss of top RPM down from 4800 to 4200 without a loss of hole shot power?
It is a 89 OMC Chevy 350 - Idle speed is not quit as smooth, but I would not call it Rough! There is no noticable loss of power, no sputtering, no missing, All spark plugs look good, almost new and are not fouling! Points have minor burning, Cap looks like new accept center pole shows some burning. Rotor shows some burning! (I will be replacing all?)
Carb looks clean.
Am I missing anything that could cause this loss of top RPM?

 

[Blk-n-Blu]

Re: Loss of Top RPM

you may have answered your own question. Look at this thread on this same page,may want to consider it too:
http://www.iboats.com/bbboard/bbBoard.cgi?a=viewthread;fid=24;gtid=1139345
8)

 

[Bondo]

Re: Loss of Top RPM

Ayuh,..............

You say it's in Dire Need of a Tune-Up,..........
But still don't understand Why it's Dogging,...??....??????

Btw,....... Any Dirt,+ Crud that Matters,............
Can't be Seen in the Carb,.......... Sometimes even After disassembley......
Much Less when it's Still on the Motor.........

Is this a Trailer Boat,..??... Or a Dock Boat,...??....

 

[Dheimbuch]

Re: Loss of Top RPM

Ayuh,..............

You say it's in Dire Need of a Tune-Up,..........
But still don't understand Why it's Dogging,...??....??????

Btw,....... Any Dirt,+ Crud that Matters,............
Can't be Seen in the Carb,.......... Sometimes even After disassembley......
Much Less when it's Still on the Motor.........

Is this a Trailer Boat,..??... Or a Dock Boat,...??....

Actually, I was saying that all of the components are showing minor wear (Sorry if that was not clear). I have seen much worse without any powerloss!
You are right about the Carb. I have not opened it up, and internal workings could be dirty! Maybe starving for fuel? maybe a suck float? The previous boat I owned would get a noticeable film when you looked down the carb, this one does not have that film!
This is a trailered boat, kept in a garage. One weekend it ran at 4800 rpms, next weekend I went to a high atl lake with a speed limit so I never opened it up, but it ran terrible, the following weekend it would barely make 4200 rpms!
I have all the tune-up parts, that is why I will install them. I was just looking for other ideas on such a sudden change!

Thanks

 

[Bondo]

Re: Loss of Top RPM

I was just looking for other ideas on such a sudden change!

Thanks

Check the Fuel Filter,.......Look for Water.......