Engine won’t rev past 2500 rpm and vibrates

[Extrasalty]

Hey so I have a 1992 mercursier 3.0 that has a bad vibration and it won’t rev past 2500 rpm. I don’t know what it could be because I’ve rebuilt the carburetor and the engine has perfect compression. I’ve given it a full tuneup and we have a brand new fuel system. Any ideas?

 

[Bt Doctur]

plug firing order or timing is off

 

[Extrasalty]

Thanks for the reply but I don’t think it’s that because we’ve had the same timing and order for the spark plugs since we’ve had the and it only recently has been giving us problems.

 

[alldodge]

I’ve given it a full tuneup

Include replacing wires or at least new cap, rotor and plugs. Might have missed a wire location as BT said

Won't hurt to check 1-3-4-2

 

[flashback]

Might be running on 3 out of 4. Pull plug wireswires

 

[alldodge]

Maybe a plug gap was dinged when installing

 

[flashback]

Pull one at a time and listen for a change in the idle.

 

[Extrasalty]

Include replacing wires or at least new cap, rotor and plugs. Might have missed a wire location as BT said

Won't hurt to check 1-3-4-2

We have replaced the cap, the rotor and the plugs we didn’t do the wire because we replaced those a few months before so they were already pretty new

 

[flashback]

Guess i should add, only one at at a time, if idle changes, its good, plug it back and go to the next. If you pull one and no change you've found a problem.

 

[Extrasalty]

Guess i should add, only one at at a time, if idle changes, its good, plug it back and go to the next. If you pull one and no change you've found a problem.

That’s a good idea we’re going to try it out tonight I’ll let you know if it worked.

 

[Extrasalty]

Hey so I have a 1992 mercursier 3.0 that has a bad vibration and it won’t rev past 2500 rpm. I don’t know what it could be because I’ve rebuilt the carburetor and the engine has perfect compression. I’ve given it a full tuneup and we have a brand new fuel system. Any ideas?

Thanks for all the replies the problem ending up being a combination of bad timing and and broken shift interrupter switch