15hp stalls

[masterp]

My Johnson 15hp J15RCDE keeps stalling under tourqe (in the water when put in gear and at acceleration). It runs fine on the muffs. On the water it won,t come up to full rpm and seems like it is skipping. Have tried both high and low reccomended plugs and have had internal and external hoses changed. Also have new tank. Problems have persisted even after tune up. Any ideas?

 

[Backlash]

Re: 15hp stalls

What you describe is usually caused by one of the cylinders not making power, either because of no spark (most likely) or not getting fuel. The first thing I would do is run a compression test, and while you have the plugs out check the spark. Let us know what you find.<br />Backlash

 

[sloopy]

Re: 15hp stalls

remove the spark plugs so you have zero compresion then turn the prop by hand.. it should turn freely. If not the prop is rubbing against something