951 has fire, but won't start

[Pacer]

silver 951

I just put my XPL back together, It turns over and has fire and its getting fuel but it won't even pop. I installed a rad flywheel, and am running stock electronics. The only thing I can think of is that I installed the cup wrong. Is there anything else that would cause this to happen. The engine is stock, it has twins and novis.

Bill I need a couple of Oring kits for one of your heads Can I just Email you billing and shipping info?

[Technical Support]

How did you align the cup?

[Pacer]

I'm thinking I put it on so that the long pickup was alingnment with the hole, to the right of the hole if you are looking at the flywheel from the front, I think I thought I alingned it with the keway because I remember if you put the rad next to an oem flywheel and align the keyway the holes are in different places. I had this same problem when I was installing it to run 800 electronics with an 800 cup. One bendix later I got it set up right.

[Technical Support]

You are supposed to put the magnet to the left of the hole.

[Jetdud]

Yes. It should be right above the left end of one of the magnets. Also, you probably know this, but to keep from having to re-tighten the RAD flywheel, you boil the flywheel before you put it on. I boil mine for about 10 min. Then carry it with a wire and slide it on the crank hub. I dry it off real well and put red loctite on the crank hub before sliding it on. This will keep you from having to retorque it. The guy at Rad told me to do that. It works.

[Technical Support]

Right edge, Jetdud.

[Jetdud]

On the rad flywheel it only slots correctly on one (actually two, 180 the other way works) pattern. I seem to remember it being right above the left edge of the magnet but it could have been the right edge. Either way, rotate the cup a couple of times to check your options out and it will be apparent. It will be right above the edge of one side of the magnet if you are using the correct bolt pattern. If your one bolt hole off it is like an inch off from being above the magnet. It's obvious it will be wrong.

Thank you tech support.

[Pacer]

I forgot to mention this is on a 99 XPL. Would you line up the big pickup the same? Thanks for the tip about boiling the flywheel jetdud. Thanks for the picture tech support

[Bill O'Neal]

The large pad is to signal the computer and tell it where the crankshaft location is in it's cycle. Yes, line it up with the hole.

[Pacer]

I don't think it's the flywheel cup. I made sure it was alinged right on the Rad, and when that didn't work I put the stock flywheel back on to see if that would make it work better. It didn't. The spark seems week, when compared to my 98xpl. What else can cause ignition problems? I don't like to be a parts changer, but I tried a different coil box, mag cover, and MPEM all with the same results. this is what I have in the boat, 99 electronics, except for wiring harnesses out of a 2000 XPL. No fuel guage, or baffle, I tried with the TPS hooked up in different positions, I don't have my VTS switches hooked up, but the grounds are attached to the mag cover. I've never ran this motor before, OEM crank and counterbalance ProX pistons 155 lbs. The squish is about 85 thou with a stock head. What else should I look for? I can't figure this one out.

[Jetdud]

This is probably not your problem, but it doesn't hurt to have extra grounds on a hard running boat. I run a ground wire from the ground on my coil straight to the battery. It is quick and painless to do and is extra insurance.

It also wouldn't hurt to get a new trigger pick up. They are not that much $ and if your spending time in the mag cup area, just put in the new one. Also, and I think you have already done this but I'll say it anyway, open up the leads on the wiring hirness connections that connect to the mag cup and electrical box and check for corrosion on their tips.

Have you tried putting some gas directly into the cylinders and then try to start it?

You need to check you timing once you have done all this to rule it out as well. I go back to basics when stuff like this happens. Start ruling things out. Like grab your compression gauge make sure your ok there too.

It's not rocket science. If its spark related, it can only be a few things.

[Pacer]

I ran another ground, and cleaned the connections. I took apart the MPEM plugs to make sure they wern't coroded on the inside. It all looks good. When I check the spark on the plugs, sometimes it looks good sometimes it hardly fires and seems like it misses. Seems like it should be a short somewhere. I'm going to change the wiring harness to see if there is something wrong with it that I can't see. The 99 flywheel cup is the one with only one big pickup. Right?
If anyone has an idea give me a cll, I'll be working on it the rest of the day.
225 405 6977

[Pacer]

It was the wiring harness that connects to the coil box. I changed that, and you could see a big difference in the spark at the plug tip. What wire do you think is shorted?

Thanks

[Jetdud]

You would have to open it up and see. I had my ground break in that harness. Thats why I ran one from my coil straight to battery. It was a work around. About a year later, for some reason I took the harness out and opened it up. Thats when I found the broken ground. Open it up and find out.

[Bill O'Neal]

Pacer,
Wrong,
A 99 magneto cup has 4 trigger pads. Pre 99 magnetos have the 2 long trigger pads.