Hi all,
Helping a freind on a 1998(Correction) mach one 700. Last winter on his last ride pulled up to the trailer and it died. Had a heck of a time getting is started but finally did barely enough to load it on the trailer(I wasn't there to see exactly how it sounded).

stored it for the summer,

Got it out of storage and pulled the carbs, completely cleaned them. One of the floats was sticking, got them working good. completely drained the gas from the tank and lines. Everything back together and still the same problem. Every once in a while it will back fire from the exhaust and every once in a while when trying to start it locks up(To much gas in the cylinders?) We have tried two new sets of plugs. Spark looks ok. Could it be timing or just a fuel problem still?

Any help is greatly appreciated.
Thanks
Randy

If u suspect it is a fuel issue, put some directly in the cylinder to see if it fires.
if not it is not a gas issue.
what color is the spark when u turn it over?
should be blue not yellow.

Thank you for the ideas.
Tried gas directly into the cylinder, after the second or third pull it backfired through exhaust. The spark is blue. When I first looked at it I could have sworn there was no spark with lights on, barely a flash with light off. My friend thinks I had one to many when we did that and it's passable ;)
Now all three of them have a blue spark.
any other thoughts?

do u have access to another cdi box? it may be timing but u would need to try another box and buying one may be expensive.
also u said u did the carbs. is the choke closing all the way off, could be flooding.
back firing is caused from excess gas in the exhast pipe.
what about the rave valves have they been checked.

No access to another CDI box :( That's what sux. Everyone else has twins. What are the chances of the cdi going out? I've got a service manual for mine = 95 but not sure if the electrical testing is the same and they call for a special tester on the 95.

i would imagine his would require the same tester.
as for the cdi going out, it is electronic equipment so it is possible.
when i blew my stator in my sled they thought it was the cdi or wire harnessand replaced both before realizing it was the stator.
in a way it was a bonus because it was all done at there cost.

have any experience testing these?

no when mine was done it was done under there warranty.
as for the raves. there is a thread in here that explains exactly step by step on how to pull them.
Do a search to find it.

I am having a quite similar problem with my 97 FIII .. 600 Tripple (Gotta love the sound of a tripple).

Mine left me 200 yards down the road, had to tow it home ... ended up taking it to the dealer
Ended up replacing the Stator, thought they had it licked.
Went to pick it up tonight .. it started on the 2nd pull, ran for 30 seconds then died.
Three of us took turns pulling, changed plugs (thought we had it flooded) still no good ... "Barney" gets to have another sleep-over at the shop. At least we don't have enough snow here to ride yet!

Big Pappa,
Thanks for the info, Keep me posted on the progress. It could help me a great deal.

Randy

have you had the compression checked yet? My machz would start but run terrible, pop when on the gas. compression check revealed a melted piston. Just a thought.

sounds like you scuffed some pistons and don't have the compression to burn the fuel. Put a guage on it. If it locked up on him then you could have bent the crank when it hydraulic'd and now the timing is out of phase. Been there done that.

Thanks for the ideas. Compression is one thing we havn't checked yet. can you say DUH????
Will do that this weekend.

Hi all
compresin is good. everything looked good internally. From what i've read on this forum I said lets pull the motor and look at the harnes under the motor. Found the wire, it's a black one rubbing against the motor mount, inside the harness. According to my 95 manuall that wire goes between the CDI and the generating coil Can anyone confirm this to be the wiring harnes problem before we put it back together?

Just as important where do ya get a service manual or CD at for the 98?


thank you
Randy

The way you explained the spark, it sounded pretty weak. Under compression, it takes more energy to arc across the gap. If you have a weak spark, it may not be firing inside the chamber compared to outside of the chamber.

If that wire is shorted to ground, that would definately cause your spark to be either weak, or no spark at all.

If you can somehow test the ignition without totally installing the engine, that would be the best say...set the engine somewhere to where you can turnit over and hook all the wiring up and stuff, that is if its possible. Then see waht you spark looks like. If it looks better than before, your probably safe to say it was the wire.

I would check and make sure none of the other wires are messed up before putting it back together though.

take the VIN number to the dealer. 1998 had a recall on rerouting the wiring harness and putting a protective coating on it. See if it has been done.