Problems caused by ,motor being propped wrong?

[N1NE1]

was out on someones boat yesterday and noticed there ocean runner 200hp would only max out at 4200rpms,what are some problems that could result in being propped wrong besides lower rpms?

 

[Bob_VT]

Re: Problems caused by ,motor being propped wrong?

Lugging too much will really hurt the motor and economy. It is similar to driving a stick shift car and starting out in 3rd gear instead of first.

The troubleshooting needs to start. It could be a dozen things aside from the prop.

 

[metriccrescentwrench]

Re: Problems caused by ,motor being propped wrong?

Yes, first off it needs to be determined if the low rpm is due to one or more plugs not firing, carbs, poor compression on one or more cylinders, etc. IF the engine is in otherwise sound condition, lugging it like that means that it's running at higher than designed peak pressures inside the cylinder which puts more stress on every internal engine part. There will be more blowby, ultimately resulting in stuck rings. And as you probably noticed, the boat's a dog getting on plane.

 

[N1NE1]

Re: Problems caused by ,motor being propped wrong?

everything is running fine,not really too bad getting up on plane, just seemed too low rpms. i have an identical motor and mine tops around 5200. i have a 4 blade 17pitch they have 4 blade 19 pitch, definetly a gas hog too

 

[emdsapmgr]

Re: Problems caused by ,motor being propped wrong?

Is your tachometer set on the correct setting?

 

[boobie]

Re: Problems caused by ,motor being propped wrong?

Even if the the tach is on the right setting it may not be a bad idea to have it verified with a shop tach. Tachs have been known to be off.