|Palmer P60 Won't rev up in forward
Post Number: 1
|Posted on Monday, August 11, 2014 - 01:24 pm: ||
WE have a 1971 P-60 in our Pearson 33. The engine runs well, temperature is fine, and the RPMs will go up to to 1600 in either Neutral or Reverse, but will not budge above 700 in Forward. If anyone has some insight to this riddle we would be glad to hear it.
|Posted on Tuesday, August 12, 2014 - 03:50 pm: ||
When I experienced something similar, it turned out that I had a valve in #4 cylinder that was intermittently sticking apparently causing my engine to run on 3... and I think multiple valves sticking sometimes 2 cylinders. The engine generally ran fine in neutral and reverse but would not rev in forward... similar to the way you describe your experience. I rebuilt the motor and have had no issues since the rebuild.
Post Number: 26
|Posted on Saturday, August 16, 2014 - 05:16 pm: ||
I suggest you take the throttle cable loose from the carb and try to activate the carb by hand to see if the linkage travel is not giving you full carb throttle.
Both neutral and reverse produce less resistance for the engine to overcome than forward gear does. So, if your engine or carburetion is marginal, you may not have the power to turn up the revs in forward. A compression check for each cylinder will let you know whether the engine is able to huff and puff enough in gear to make rpm.
There is also a possibility that you have something wrapped on your drive line that resists turning the shaft. In neutral, you would not notice it, and in reverse, your clutches may slip, but in forwards, the drive line is locked up. So a drag on the drive line would be most noticible in forward.
You could even uncouple the shaft, push it back a little and then try for your revs, with just the engine and tranny involved. Somehow, you can isolate the problem, or eliminate the potential sources from being able to cause the problem.