Mercruiser 165 boggin... Rev limiter??

[tonto340]

Hey all,
87' 165 mercruiser 4 cyl.

Just did tune up(dist cap, rotor, contacts, wires, plugs, timing), just one issue left to address. Once the boat reaches around 4000 rpms its bogging down. not sure if there is some sort of rev limiter but throttle still has a little ways to go and max rpm wot on engine is 4600. If not what could it be?? Thanks in advance.

~Nate

 

[tonto340]

Re: Mercruiser 165 boggin... Rev limiter??

Ttt

 

[Don S]

Re: Mercruiser 165 boggin... Rev limiter??

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.

 

[tonto340]

Re: Mercruiser 165 boggin... Rev limiter??

So, its not really a Low RPM WOT its more of a bogging issue. It has gotten worse, i'm going to change fuel pump filter tomorrow. It is now reaching 3000rpms and boggin down under 2000 and sometimes it will shut right down. if i keep it around 2800 it will run fine but as soon as you give it throttle it will bog down. If filter doesn't fix it what are my other options??? I'm thinking it has to be a fuel issue. but its def not bad fuel, i've only put 93 in it and it doesn't sit for long before it gets used and refueled. Hopefully filter fixes it but i guess we'll find out tomorrow, anything else i can check while I'm in there tomorrow?? It is docked at mercruiser dealer marina so I should be able to pick up most parts. Thanks again!!!!

 

[180shabah]

Re: Mercruiser 165 boggin... Rev limiter??

So, its not really a Low RPM WOT its more of a bogging issue.

See list above

I'm thinking it has to be a fuel issue.

see list above

i've only put 93 in it

Waisting your money on premium - it was designed for plain old regular and should run just fine on it.