426 w/ no spark

[jboomer]

My buddy just got his '00 426 put back together after completely rebuilding the bottom and top end. But, he's not getting any spark. This is what has happened and what he's done:

Original problem: A shim came loose in the bottom end and the engine basically ground it up. The metal cycled through his oil pump, tore up the cylinder walls and piston, and chewed up a couple of the gears in the bottom end. After the local Honda dealer replaced ALL of the parts in the bottom and top end (all gears, cylinder, piston, valves...everything but the cases) they refused to repair the engine (the whole mishap was their fault....but thats another story). So, my friend, with the aide of his repair manual got the engine completely reassembled (after washing EVERYTHING in his parts washer) and put back in the bike.

He never removed any of the electrical connections attached to the bike, so these should be in order. He's disconnected the kill switch to rule out that as a potential problem. And he's put a new spark plug in. The only thing we can think of that may be a possible problem: when he removed the stator, there was A LOT of ground up metal and metal chunks in the stator housing. He washed all of this out in his parts washer and nothing appeared to be damaged. Could the solvent have affected the stator in some way?

We're lost as to what else may be the problem. Like I said, everything was in working order when the engine was pulled (approx. 3 months ago). What are we missing?

 

[kawdude]

I have ask the question regarding why the honda dealer hosed up the bike in the first place.

Any chance the metal cut the wires around the coil or ignition?

 

[jboomer]

We don't have a local Yamaha dealer here (within about 2 hours drive), so the bike was taken to the local Honda dealer (who said he could fix it) when 3rd gear went out of the tranny. Well, the mechanic, after taking about 5 months to get the engine put back together, forgot to put a shim on some shaft located within the gearbox.

My buddy, trying to save some coin, had already pulled the engine out of the bike and dismantled the topend. So, when he got the cases back (reassembled w/o the shim) reassembled the topend and put the engine back in the bike. Well, after kicking a couple of times, we discovered the engine had NO compression. After disassembling the engine again, we found two intake valves had been reassembled in the wrong place (causing one of the valves to remain open all of the time...effectively preventing any compression). So, we had to take the head back to have the mechanic switch them back. Well, we got the engine put back together and in the bike and it fired in like 3 kicks and ran fine. We took it to the local track so he could break the engine in. After running it about 10 minutes, that shaft (missing the shim) worked loose and cycled itself and two circlips throughout the engine.

My buddy had put a new piston and rings in and the shop had to replace like 3 gears and 2 shift forks (when the engine was taken in the first time). Well, the shaft and circlips ruined the entire bottom end AND the piston/rings and tore chunks out of the cylinder. After my buddy demanded they fix it for free (it was their screwup AND he had already been off the bike for 5 months), they just ordered ALL of the parts to rebuild the engine and gave them to him for free, but said they weren't going to fix it. He pretty much got a brand new engine, except for the cases and only had to rebuild it himself. It's not the first time he's rebuilt an engine and he's confident he got it back together correctly.

We checked the wires in the stator and everything appeared to be in working order. Like I said, he just dumped the whole thing in his parts washer and cleaned all of the debris out. But, for some reason he's still not getting any spark...

 

[j_freak]

I don't know a whole lot about new bikes, so take anything I say with a grain of salt...

Could he have gotten a piece of crap lodged somewhere in one of the coils that's shorting it out?

 

[MXTex]

A buddy of mine had this same problem (no spark) with his 2000 426. Ends out the connection at the spark plug boot had come loose. Apparently this is a common problem with these bikes. Maybe it's something this simple. I hope so.

 

[jboomer]

I asked him if it was possible any of the metal was still stuck in there shorting it out, he's positive he got it all out though.

I'll call and tell him to check that sparkplug boot.

Thanks guys! Any one else with an idea, share it, because we're all out!

 

[j_freak]

:think: I wonder...

Could the solvent have eaten the insulation off of the wire?

One other thing I've heard of is that if you drop the flywheel (or hit it with a big hammer), it can damage the magnets. Might wanna take a wrench or something and check that all the magnets are still strong

If all else fails, take a multimeter and check every single wire for continuity while you wiggle and twist them slightly.

Other than that, you'll have to start replacing components... :ugg:

 

[jboomer]

Well, he found the problem today. He bought the multimeter and started at the sparkplug and worked his way back, testing wires. Never got ANY spark. Turns out, two wires in the stator (the one filled with chunks of metal) were cut on the underside, preventing any kind of continuity. The wire "sheath" itself was still attached at the top, which explains why he thought they were undamaged. So, he ordered the new stator ($160 with a 15% discount) and should have it back together next weekend. Thanks guys!