coils causing my problems?

[lyncraft_mechanic]

I have a 15hp johnson model j15ecsd that won't idle down with out stalling, I checked the compression and both cylinders read 115psi, the carb. has been cleaned with carb cleaner and blown out with compressed air so i don't think its a fuel problem but during a spark test i noticed that both coils arc to the block if a plug wire is removed when it's running. do you think that new coils will correct my idleing problems?

 

[freddyray21]

Re: coils causing my problems?

doubt it's the coils if both are firing. I would suspect an air leak somewhere. Either a gas line not tight or a leaky gasket. vacuum leak at fuel pump ect.

 

[Benny1963]

Re: coils causing my problems?

yes if there going to ground under load .try cleaning your coil ground and
and wires install some electrical grease in your plug wire connections
if the coils keep arcing you may want to change them.
some one with more experiance than i will show up shortly.
good luck

 

[freddyray21]

Re: coils causing my problems?

assuming then you have adjusted the carb correctly

 

[lyncraft_mechanic]

Re: coils causing my problems?

the carb. is adjusted correctly, air adjustment is roughly out 1 1/2 turns i readjusted the float so its level and all the jets were removed and cleaned. I doubt its an air leak beacuse i just replaced all the fuel lines but i will recheck them again. any other ideas? should i replace the coils?

 

[freddyray21]

Re: coils causing my problems?

my experience on coils are that they either fire or they don't. When they do break down it is usually under a load and at high rpm. 1 1/2 turns may be a lot. I find most of mine will run better at about 1 turn or less. Take it down a half turn and see if it will idle. I will usually let them run at a high idle and turn the screw in until I can bring it back to an idle. Then fine tune it. there is no set amount of mixture as every motor will be a bit different.

 

[motorcyclist]

Re: coils causing my problems?

I dont think it is the coils, usually a weak ignition will show up under heat and high pressure when under load. as mentioned before, I would look for a vacuum leak. My 1970 6hp will idle so low, one can almost count the firing of the cylinders.

Good luck

Bill

 

[mikesea]

Re: coils causing my problems?

make sure the timer base under the flywheel is rotating ok.Also,.there is a plastic cam that the carb roller ridef on under the flywheel,they sometimes crack and fall apart ,screwing up the timing sequance,the plastic roller on somw have a plastic insert that also falls apart.If the eng.seems to smell flooded,you may have a fuel pump diaphram that failed leaking fuel into the eng .flooding at low speed

 

[lyncraft_mechanic]

Re: coils causing my problems?

I will hold off on replacing the coils then, i will look today for any type off fuel/air leakage and also take a look at the fuel pump. the timer base is operating perfectly and the cam that rides along it is in good shape. any other suggestion would help out!!!!

 

[lyncraft_mechanic]

Re: coils causing my problems?

finally got the motor to idle down without stalling but it seems like it's skipping although i have strong blue spark on both cylinders. however the coils still ground out to the block mainly during a spark test. do you think it could be grounding out someplace i cannot see causing the motor to skip?

 

[tashasdaddy]

Re: coils causing my problems?

you could have a bad plug wire shorting to the block, or a bad plug boot shorting to the block.

 

[freddyray21]

Re: coils causing my problems?

your skip is most likely a lean sneeze. turn the low speed needle out about a quarter of a turn.