Guys, I have this ongoing big problem with starting my Raptor. Before the 686 top end overhaul, I was running a 10.75/1 JE (stock bore), and starting was slow. Now with the recent 686, with another 10.75/1 JE, starting is not happenning....simply will not turn the engine over. I have since then installed a Grizzley battery and it's in top shape. Starting is still slow. The slow starting burns starter relays like no tomorrow. Starting only happens by jumping off, removing the seat, and jumping the starter over directly too the battery....then starting is still slow (hard on starter as well). I have installed a new decompression pin and checked timing again and again...it's correct. I also moved the battery ground directly too the frame and checked / cleaned my starter. Can anyone help? THanks!
Gary

 

It is possible to install the decompression pin 180 out. The mark on the pin has to be on top and lined of with the top mark on the timing gear. I messed this up the first time when putting mine together.

Also, if you are pulling extra current and burning out the relay, it could be a bad starter motor.

You can ohm it out to check it, but I do not know the resistance range off hand. It may be in the shop manual.

 

If the decomp pin is installed incorrect, it will not protrude out of the cam too bleed off compression by hitting the exhaust rocker. Mine works good. I guess thats the next step, checking the starter for proper ohms. Thanks!

 

Yep, that pin sticks out if it installed correctly.

I think you would be able to tell by the sound if it was a compression release problem. It would really slow down turning over on the compression stroke, but fast on other strokes. However, I heard that people remove the comp release all together and don't have a problem. If it is slow all together then the problem is most likely electrical related.

I am sure you checked this, but a loose or corroded cable connection can pull extra current. This is due to contact resistance loading the starting circuit. You may want to re-check all high current connections.

 

I had that problem too gary, decomp pin was the problem. I could only pull start it.

 

what did you gap your rings at??

 

Good question. I don't remember the exact specs, but I do remember I set them on the low end of the spectrum advised. I have a ring filer, so I can set them exact. I wonder how much cranking compression is too much for the stock starter?

 

There are threads on this forum where I read about someone using a high compression piston with a disabled decompression system. They said it is no problem.

I am running 11:1 and my Raptor has never started so quickly in it's whole life.

You would not experience engine tightness from improper ring gap at cold engine temps. This would only be a problem at operating temps. If for some reason, your ring gap was tight cold, you would have probably noticed it when installing the cylinder.

It is not uncommon to have the ring gap too tight and have it pull the cylinder out of the case when romping it. (It happened to me) So, if your gap is such that your engine is tight cold, you would have seen bigger problems when running.

 

I would test the starter motor.

 

It's a monster too start when cold, but fires right up much easier when warm. Thanks guys.....I will check the starter.
Gary