Super poor running force 50

[shindig888]

91 force 50hp. Steady decreasing performance! She won't idle anymore, new plugs, tried different oil, de-carbed, water pump good, float level good, idle mix screw good, fuel/oil good, f. pump ok, whats next? She idled great and ran ~smooth for the first 5 trips, since I bought it. Now can't run well at 2500 and below, after 12 trips. Runs good Full throt. I thought it was loading up... New plugs and its no better. Can it be crank seals? what are the symptoms of this? Can I test? There maybe what appears to be some darker oil forming at the p.head base?... She was always clean inside. Any input is welcome...Please, the springs are startin' to bite...

 

[roscoe]

Re: Super poor running force 50

Have you checked the compression?<br />Check for a cosistant and strong spark.<br />How do the plugs look?<br /><br />Try running it with the top cover off.

 

[shindig888]

Re: Super poor running force 50

I checked the compression when I got the motor and it was great. 140 I think, will try to test again. I run the engine up in a barrel, and have tried all kinds of things. At this point it won't idle without dieing and if I idle up to 1500 or so it runs real rough, almost like its dropping a cylinder and then picks it up again, and off again. When I pull the bottom wire, while it running, it doesn't change much. That wire with the cap pulled off and arcing to the head makes a good blue spark but when I arc to the sparkplug its dull and not much color. That cylinder doesn't pick up much either. I tried a few different plugs and it still seems about the same. when I pull the top plug it dies right away. The plugs are oil deposites anf fairly wet after running for 4-5 hours in the chuck yesterday. I pulled a bucket so I could troll with the revs up a bit, but she would not idle for long.

 

[roscoe]

Re: Super poor running force 50

So the problem is associated with the bottom cylinder, probably weak spark.<br /><br />Check all connections to be sure they are good and tight.<br /><br />Swap positions on the 2 coils. Now test it like you did above, by removing plug wires and noting engine response and spark.<br />Does the problem stay with the bottom cylinder or move to the top one?<br />If it goes to the top one, replace that coil.<br /><br />If problem persists on the bottom cylinder, problem is likely the cd module.

 

[shindig888]

Re: Super poor running force 50

the problem stays with the bottom cyl. the top cyl. jumps a real good blue arc to the spark plug nipple. the bottom one stays real faint to the plug, but it is really bright spark to ground. swapped plugs and its the same. can I swap the wires to the module to so I can prove its the box?

 

[roscoe]

Re: Super poor running force 50

Did you swap the coils?<br />If you swapped the coils and the problem stayed with the bottom cylinder, then problem is before the coild. Most likely the switchbox module, or a really bad connection somewhere.

 

[shindig888]

Re: Super poor running force 50

Yes I switched the coils..bottom stays bad. checked (wiggled and pulled) all wires while it was running in the barrel and it was running on only one (top). I feel if it was a bad wire it would kick in on the bottom cyl. but she fires only once and a while causing a stutter. basicaly it is not firing on the bottom (weak spark). maybe once and a while. Can I make it fire on the bottom and probably not the top by switching the cdi wires 'round? which wires are they? I could try an educated guess by comparing the wiring patern. or if someone is sure that would be welcome.

 

[roscoe]

Re: Super poor running force 50

Not sure if you can do that and keep the trigger firing at the appropriate time. Usual testing procedure for cd and trigger requires a peak reading dva meter.

 

[shindig888]

Re: Super poor running force 50

Is each side of the CD biased as per engine rotation? Or does it really matter which side of the unit is used for cyl. 1+2

 

[roscoe]

Re: Super poor running force 50

Cd stores energy and releases it when the trigger tells it to.<br />I guess you could swap all the cyl 1 and cyl 2 wires from the trigger to the cd, and then swap the cd output wires.

 

[shindig888]

Re: Super poor running force 50

Good stuff!, maybe I can try that , If someone knew which wires where what , it could make things easier, any replies are welcome. Thanks roscoe I apreciate all your input, keep it coming. I'am well inclined, just need a guide.

 

[shindig888]

Re: Super poor running force 50

Thanks roscoe. Iam going to put a new cd unit from std. magneto in it. Hope it fixes all.