CAn'T reach WOT RPM !!!

[betayv]

HEllo there I have a mercruiser 228/305 on a 23 wellcraft, I cant reach WOT rpm, MAX RPM reaching is 3100, I tought the problem was the carb but just installed after been rebuild by a shop, new cap, rotor, spark plugs, spark plug wires, new fuel pump, new fuel/water separator, what else? probably timing? I dont know what else to check thanks...

 

[tschmidty]

Re: CAn'T reach WOT RPM !!!

Well what kind of speed are you getting out of that 3100? Might be timing but just may be the wrong prop since we don't really know the lineage of the boat. Any idea of the prop on it? How long have you had the boat?

It sounds like you are on a bit of a parts replacing kick. Another thing to look at would be the coil which most people neglect to check/replace. When they start to go bad they can't keep up the voltage at higher rpms. But again, not to encourage you to just replace another part.

 

[Don S]

Re: CAn'T reach WOT RPM !!!

List of possible causes of low WOT (Wide Open Throttle) rpm.

In no particular order

Engine Won't Reach Operating RPM. Check

1. Fuel condition. Type and Octane possibly old fuel
2. Propeller pitch or diameter, damaged blades
3. Restricted fuel pickup tube or anti siphon valve Fuel System Test
4. Crankcase oil volume, high oil level can cause aerated oil and lifter collapse
5. Marine growth on hull and outdrive
6. Wrong gear ratio in outdrive
7. Restricted carburetor air intake (clogged flame arrestor)
8. Restricted exhaust system (broken exhaust shutters/flappers) in engine transom shield or drive
9. Poor cylinder compression Compression Test
10. Carburetor defective, or wrong type.
11. Fuel pump pressure and vacuum
12. Boat overloaded, improperly loaded, or improperly trimmed.
13. Engine Overheating
14. Engine timing and ignition system operation
15. Remote control cables and linkage for proper travel to open throttle plates fully.

 

[betayv]

Re: CAn'T reach WOT RPM !!!

the speed that Im getting is 29.5 mph the boat is a bowrider I did a complete tune up including the coil because I used the engine for two years without any issues in my other boat, the prop that im runnig is a 4 blade 14 inch 21 pitch....

 

[fossill]

Re: CAn'T reach WOT RPM !!!

disregard

 

[OnTheWaterNow]

Re: CAn'T reach WOT RPM !!!

I woul check to see if all Your cylinders are fireing you may only be running on limited number of cylinders that was my problem when not reaching wot.it was do to switchbox.Dons checklist covers that