Ka-clunk! Now the chain is jammed and slack!

[Mannix]

1983 SOHC Maxim

I'm making a left turn from stopped at a light. I start rolling in first and shift to second right before getting into the turn. I hear clinking and then ka-clunk as I'm letting out the clutch, maybe I was a little quick letting it out, but not much.

I hear a rattling, the bike is not in gear, I roll to the side of the road. The engine turns on fine (well, I need to troubleshoot a few things, but it turns over) but shifting does nothing. I push into a parking lot and see the chain is off the rear sprocket, and when I try to thread it back on, I find that it is jammed up on the front sprocket end and won't turn.

I'm still in newb status, but I've been reading Mark Zimerman's Essential Guide to Motorcycle Maintnenance . Haven't had time to open her up, but should I go for the countershaft or the clutch first? Or is there some third possibility? And if it is the countershaft sprocket, should I go ahead and adhere to the always change the chain when you change the sprockets rule?

Thanks guys!

 

[16VGTIDave]

Good to hear you survived the lack of maintenance, hopefully the engine case did as well. Replace the chain and sprockets and inspect all around the countershaft sprocket for damage while you are in there.

While you are waiting for the parts to arrive, read chapter 2 of the service manual and perform every task listed there so you can get caught back up on the regular maintenance that obviously hasn't been done.

And be thankful that you can walk. Many a motorcyclist over the years has lost the use of their ankle from a flailing chain...

 

[Mannix]

I have been hypothesizing if this happened on the highway what the damage would be (as I cross myself). Thanks Dave, gonna see what's doin tomorrow. Tell you what I find.

 

[JPaganel]

My bike threw the chain when the chain stretched out beyond adjustment.

I bet you are in for a new chain. Also, there is a good possibility your sprockets are worn - take a close look at them.

When you order parts, get a clutch rod seal. It's only $6 or so. Mine got messed up when the chain fell off and that results in an oil leak.

 

[Mannix]

Having trouble figuring out the chain and sprockets I should order. I've got the '82 owners manual from a thread on here, and the Hayes workshop manual for XS250, 360, 400 '75-84. Again, I'm on an '83 maxim as far as I know. The '82 owners manual says 50 HDSS with 102 links with 30mm slack. The Hayes doesn't seem to have a chain spec for changing for some reason, but it does say 20mm slack for adjusting. It suggests ordering from Renold Limited.

Not sure what to trust, and confused as to why there isn't the standard three-digit chain dimensions listed anywhere. I plugged my make and model into JC Whitney's site and got hits back for chain. Should I trust that, and if I have to buy a chain that's too long what do you recommend to cut/adjust it, one of these chain breaker tools, or a saw? Shall I start pulling stuff out of my bike and hope the dimensions are still readable. I guess I can also count the links and teeth and measure the diameters. I had wanted to get the parts coming ASAP, I don't have we garage to work in.

 

[JPaganel]

Chain breaker is best.

I got a chain longer, and measured the old one once I took it off.

 

[willem]

My Seca is mechanically the same as your Maxim. I recently put a new chain and sprockets on, I used a DID chain (they're the best available ones, I think). It was a DID 530V chain with 102 links. Sprockets are 16 and 38 teeth. I had to take off one link (or is that a double link, either way it's the minimal amount to take off) to make it fit, but it's better to have one too long than too short of course. I used a chain breaker, but broke the chain breaker pin before breaking the chain. Guess I wasn't doing it right, so be careful.

ended up hammering the pin from the breaker through the chain to 'break' the link. Was kind of a pain in the *ss, but it worked. Been riding with the new sprockets and chain for a few weeks now (daily riding) and I haven't even needed to adjust the chain tension. Would recommend this chain any day.

 

[Mannix]

ok, took the countershaft cover off and got a good look at the jam. The sprockets actually look
like they might have survived, check out the pics, yea the nuts took a beating though. I have a leak from my left Carb and possibly also an oil leak that might have been the cause (I put some seafoam in the tank and leaks started). Should I still do the sprockets?

Thanks Willem, I also have a 530 but with 100 links and looks like I may have been due for adjusting; too much slack by eye ball. Also, I read somewhere that o ring chains don't fit our cases, anyone got the lowdown on that? I'll probably just stay standard to save some $$$.

 

[willem]

Well, your front sprocket is definitely in need of replacement. That one has been the main problem, it's rounded off on one side (the right side of the teeth) so the chain slipped off over there. The rear sprocket looks so-so wear-wise, but also not great. And with the nuts taking a beating and the front sprocket being replaced, I'd do that one too. They wear into each other and the chain, so you should replace the set altogether. Some people only change one of the two, but that's not so beneficial for your chain lifespan. And relative to the chain itself, the sprockets are not so expensive.

So I would highly recommend you change the whole set.

Your engine is definitely leaking oil somewhere, looks like it's coming from around your starter. Also the carb leak is never a good thing, but that's probably not related to the chain breaking. I see you don't have an inline fuel filter either, install that asap. Costs 3$ and will save you a lot of trouble.

You might consider getting a gasket set and opening the engine for a service. That way you'll be able to fix your oil leak. Big job to do, though. If you have more than a few drops of oil under the bike after you've left it overnight, I'd seriously get on that. Otherwise you might want to hold off, just remember it's quite dangerous if you spill oil while riding and ride over it, you might lose your traction in a split second and fall.

 

[Lou Ranger]

Having trouble figuring out the chain and sprockets I should order ...

I have the same bike and had the identical chain break on a shift from first to 2nd.

http://www.xs400.com/forum/showthread.php?t=10273
​

Check the casings around the front sprocket for perforation. The chain folds and bunches in between the casing and the front sprocket and chews into the soft aluminum. I was luck and it only perforated the casing around the sprocket and not the adjacent engine casing. I was told I was lucky that it hadn't chewed through it too - in which case the engine could be done. I repaired the small holes in the sprocket casing with J-B Weld simply so that chain oil wouldn't get flung through the small holes and hit the hot engine casing. I recommend it if that's the case on yours.

I replaced with a DID 530 chain which came in 110 link length. Thanks to 16VGTIDave, I learned you only need a cheap grind wheel, a small, regular power drill and a steady hand to take off the links you can't use. If you think you want to go with 102, I recommend taking 7 off first, just in case. Dave also talked me into taking fewer off so that I could lengthen my wheelbase by about 3/4". Doesn't leave me with much adjustment, but grinding off a link is easy enough that when I need more adjustment, I will just do that.
Good luck and post some pics of the casing etc once you get the sprocket off ....

PS - you may want to consider buying a 17T front sprocket instead of the 16T. Depends on how you ride. If you love keeping the revs over 7,000 all the time, don't bother, but if you are like me, and hate how high it revs in top gear at 55 mph, then you will enjoy shaving 500 rpms off at that cruising speed.

 

[Mannix]

Thanks for the link to your thread Lou, I definitely have some great fudge brownies in there. I'll look better next time I get in there (and clear away the chocolate ganache), but it seems that the casing got a scratch but no actual perforation.

Thanks for the good eye Willem, I see now the front sprocket is pretty well lopsided. I put in a fuel filter first thing last year, but because of the PO's stop valve the angle of curve was too great. I came home the night after installing it and filling the tank to see the fuel filter cracked open and nearly half my tank trickled onto the ground. But I have another one to put in (guess I'll remove the valve? Never use it really; ironically came in handy to install the fuel filter ). I've got a few issues I was looking to chase down, the chain and sprockets Jumped to the top of the list :/

Also LR, thanks for the 17T recommendation, that high rev has always made me anxious. Maybe when I get a sport bike in 5yrs and I'm popping wheelies!

 

[Lou Ranger]

... thanks for the 17T recommendation, that high rev has always made me anxious. Maybe when I get a sport bike in 5yrs and I'm popping wheelies!

You might be able to get through this if you have enough spare time: http://www.xs400.com/forum/showthread.php?t=7592
With the 17, you will find that the bike is just as much fun to drive in the high rev range (like a sports bike?) and nothing changes except the speed at which each gear change occurs is a bit higher. The only time it is worse is starting out from a dead stop on an up slope. That hardly ever happens so this price is well worth it.
I test rode a 450 Honda Nighthawk with a 6th gear overdrive. The rpm/speed ratios for the first 5 gears are almost identical to those of my Maxim with the 16T and then you get to shift into 6th and take 1,000 rpm off the cruise speed. If I ever get the urge for a sports bike (when cows fly?), it will have to have a very tall overdrive gear before I'd be interested.

 

[arfstrom]

Oops, wrong window

 

[Scorpio1963]

Chain breaker is best.

I got a chain longer, and measured the old one once I took it off.

Actualy I die grinder with cut off wheel is much easier