failure to accelerate

[Freeman79]

Hey guys, my 1962 Johnson qd23 idles and runs fine but seems to only accelerate to about half the rpms that it should. Based on videos I've seen online, it should easily get by 14ft aluminum boat on plane with just me in it, but it's not even close to doing so. I have verified that the butterfly is fully opening, the throttle linkage fully rotates. I have new coils, points, and condenser, my point gap is correct per the manual. the plug wires and plugs are not new. Any feedback would be welcome. Thanks

 

[Joe Reeves]

Re: failure to accelerate

What is the compression psi of the individual cylinders?

Have you actually checked the spark (with the s/plugs removed) to see if the spark jumps a 3/8" gap with a strong blue lightning like flame?..... a real SNAP! If not, do so.

Are both cylinders firing? Check by removing the spark plug leads, one at a time while in this problem range. If when removing a plug lead, there is a noticeable drop in power... then obviously that cylinder is operational. If there is no change in power, then that cylinder is not firing.

Let us know what you find.

 

[Freeman79]

Re: failure to accelerate

Thanks, I will

 

[yorab]

Re: failure to accelerate

Your thread title reminds me of Cool Hand Luke:

"What we got here is...failure to accelerate."