Engine not reving to full throttle lacking power

[B Naquin]

I have a 1995 Tahatsu M60B that is not performing well at full throttle. This started out intermittently but is now 95% of the time.Seems to not be running on all cylinders but all cylinders are firing. This was verified by removing one plug wire at a time. Engine seems to sputter like it's trying to fire at times. Went through carburetors and all three were spotless. There are no restrictions in the fuel lines. Is there a way to check the CDI other than just changing it out? Does anyone have a suggestion?

 

[Luke000]

Have you run a compression check on all of the cylinders? It would be the next thing I would check. When you do, all of the cylinders should be within a few PSI of each other.

 

[B Naquin]

All three at 125

 

[F_R]

Of course you did try new plugs, didn't you?

 

[B Naquin]

Yes, new plugs, NGK

 

[brim_buster]

then I would look at fuel pump and diaphram

 

[B Naquin]

Brand new diaphragm pump with gaskets. Pumping fine and there are no restrictions in the fuel lines. This was also verified by changing tank and fuel line

 

[brim_buster]

https://www.tohatsuoutboardparts.com/Parts-Books.html time to read the manual

 

[brim_buster]

How did the reed valves look...Im just going down the list like I would if it were mine..grasping

 

[steelespike]

There is a Honda,Tohatsu, Nissan forum.
Perhaps an exhaust leak inside the cowl.
Is it cooling correctly?
A factory service manual will have the test procedures of the ignition
And will save frustration.

 

[B Naquin]

Reed valves look good. Seem to be sealing off. There is no backfiring through carburetors.

 

[B Naquin]

Was having an issue with the cooling. Did take down the water pump. Impeller had slight wear but was not in terrible shape. Cup hada crack in it. Changed impeller and cup. It has not overheated in the last 4 times ran but.....