So it started off as a ride where my son's Z400 kept stalling. After MANY re-starts that day, his starter stopped working. It couldn't just be a simple starter motor, cuz that'd be too easy. It turned out the starter clutch assembly was pooched. All 6 of the allen head bolts sheared off. THEN, the sheared bolts rattled around inside the magneto cover case, and shredded the stator.

I noticed what appears to be about 1-2 tablespoons of motor oil inside the magneto cover. The only thing I can think of is that the crank seal is also leaking. I hope these loose, free roaming allen bolts didn't also shred away at the oil seal, although I think that seal is too well protected behind the large starter gear. HOWEVER, the stator got shredded and there were all kinds of loose chunks of copper wire hammering away inside, and I wonder if maybe these were able to wear on the seal??

I haven't been able to remove the starter gear assembly because I'm waiting for the special flywheel puller tool. The best deal I found was off of ebay, $40, shipping included. So keep that info filed away for when you need it. It is 38mm, 1.5 pitch, female thread.

Anyways, assuming I have a crank seal leaking, is there anyway to do some type of repair without splitting the case, and removing the crank?? Is it a big deal if a bit of oil seeps inside the magneto cover?

 

I would think u would be able to get at that seal once u remove the flywheel. use 2 small screws to grip it and work out.

 

I'd be committed to replacing it then!!

After taking another peak, I'm wondering if those 2 smaller starter gears (that transfer the idler gear energy to the main starter gear) need to be oiled to engage/disengage. They sorta slide on a shaft, and I notice there is some type of spring loading insde the case, pushing against them. They may be sealed from the rest of the magneto area, once the cover is back in place. Maybe some oil just dripped from that spot and into the cover, as I removed it???

 

I notice the one flaw the z400 has is that they do not like multiple hot restarts....... I've seen/heard this similar situation repeated several times.

IMO it illustrates how people who ride slow and technical stuff would be better off on a 400ex or big bore, something with more low end grunt. The z400 does not like to stall or lug. Too much clutching and too many restarts seem to cause problems for people.

You should be OK with that seal....

 

geez, I never knew it was that common. It's a drag cuz my son loves jumping it and wheely-ing, along with the break-neck throttle response. HOWEVER, riding our terrain, and the friends we ride with, most of them are on 4x4 monsters, and we're on technical rides.

I had a closer look now that I received the flywheel puller and stator today. I think I've been led horribly astray by the Suzuki parts guy. There SHOULD be oil inside when you pull open that magneto cover. Heck, you can see where it leads to the drain plug. Behind the starter gear is the crank bearing, and it needs oil. not sure if the stator gets oil too, or not. Maybe once the cover is back in place, it somehow seals off the stator part. but oil in the area i described is normal and it should definitely be there.

this whole post was started because I wasn't sure if I should replace the gasket on the magneto cover. The 'zuki dealer said there's no oil in there, it's more like a dust cover; don't bother replacing. WELL, he's wrong! There is mega oil in there!! anyways, gasket isn't broken, but I'll err on the cautious side and apply some of that 3bond liquid gasket, aswell as leaving the old gasket in place. 3bond should fill any cracks, and it is like a semi-soft material that doesn't change the thickness.

 

Well I hope you get your Z up and running soon Ned. Wish I could be more help, but you're alot deeper into the motor than I've ever been. As far as I've been is just to pull the head off, and the clutch for new DID timing chain (which I recommend you change, if you haven't done so already).
And as far as lugging the Z, I've never had a problem (not saying it isn't true). My 100 pound wife rides an Ozark, I'm always lugging around waiting on her [img]i/expressions/face-icon-small-smile.gif[/img]

 

actually, I'm really not as far as you think. I just removed the magneto cover. the stator comes off on the cover side, as it's attached to it. THEN, you're looking at the rotor, which is one bolt on the crank. Remove bolt, then use the special flywheel puller and the rotor (for the stator) comes off. remove Woodruff key, then the starter clutch comes off, along with big starter ring gear.

think I'll replace the key aswell. didn't seem like there was very much of it sticking out, to slide the rotor over.

I've never done my timing chain. are these a weak point on the 400? I imagine the chain letting go would do a number on the top end, bent valves, etc..

 

Yeah they're weak, well from what I've read, it may be the auto tensionizer. When I checked mine it had just a couple of clicks left, and there was a noticable ticking sound, almost a rattling.

 

good to know I might get a small warning with some unusual noise. I just wanna get this thing back together and get jr. riding it. I work on it more than he rides. sport quads really don't like the abuse the trail riding/mud throws at them.

next time I'm bored, I might get pro-active and tackle that timing chain. thanks for the heads up.

 

Yee haa! Parts arrived yesterday and i got a chance to put it all together today. It runs perfect. Let's hope it stays that way.

Now here is some really scary math. IF....... I would have taken quad to a shop and said: "Just fix it": New parts, US retail from a local dealer, it would have cost around $1,300. Guessing at ANOTHER $300 labor.Now there were more parts than what I needed, but these are the exact parts I got from ebay. If I bought the parts on-line from a discount place, would have been $1,000. If I bought only exactly what was needed, from discount place, $470.

My ACTUAL cost: used parts thru ebay = $110 + $14 for a rubber o-ring from dealer, plus $40 for a puller tool, plus oil & filter ($10) = $180. I never counted the cost of the puller tool in above calculations!