Suzuki Burgman USA Forum banner

Broken ring

9K views 43 replies 13 participants last post by  Ndlax59 
#1 ·
The engine stalled while stopped at a traffic light last week and would not start (2013, 400). When I got it home I found good spark, fuses were ok and a shot of starting fluid while cranking had no effect. Looking for a reason for poor compression I checked valve clearances, within tolerance but toward the tight end. Digging deeper I found the top ring broken and the bore gouged pretty bad. Sometimes you can find a complete engine on ebay for about what Suzuki wants for a cylinder and piston. Not sure what my next move will be.
 
#5 · (Edited)
That is a shame about the broken ring, very unusual for one of these engines, since you have the top end all apart, you might as well buy the parts to fix it, if eveything else is OK with the engine. Use standard piston if the bore can clean up with a glaze removing hone, OR have it bored out to clean up the gouge. If you chose to bore, buy an oversize piston first and hand it to the machine shop, so that they can bore and fit the cylinder to match the piston with proper clearance.

You can buy a standard piston with rings and wrist pin (83mm bore) for $35.99 w free shipping here:
https://www.aliexpress.com/item/Mot...lgo_pvid=010fc1bc-3848-4b84-9b32-237841289718
They also have OVERSIZE piston/ring sets if you choose to bore out the cylinder.

They also have the cylinder base gasket and Cylinder head gasket for $14.24 w free shipping here:
https://www.aliexpress.com/item/Mot...lgo_pvid=0c9b5a47-8081-4e2e-9870-1d16f851b775

Always double check parts to be sure that they fit your make, model and year.

I have bought a few things from them, and what I have bought has been good so far. I bought a drive belt for $114, I'll be putting it on in a week, and the deals on starters and such items look to be unbeatable prices.
 
#8 ·
You Must have had A Defective Ring That's All, Manufacture Error

Bolzen, there Big Bore for are 400's, Don't look like theres room for Much but 450cc

Elliott,
 
#10 ·
You can check with the machine shop and see if they can do the cylinder coating, or it they know where to send it to get it done.
I have not seen the cylinder bore myself, so I was wondering if it is an aluminum bore or a steel lined bore? If it is aluminum, I would certainly see the need for the bore coating. Myself. I love steel cylinder bores, as they tend to give less trouble and long service life.
 
#11 · (Edited)
The 2003-2006 400's have a steel sleeve-type cylinder, and I believe the 2007 on have nikasil coated aluminum. I've never heard of anyone boring and re-coating a nikasil cylinder although it's probably possible I'd worry then about getting an oversized piston- it doesn't seem like they're for sale anywhere. I'd say it's best to get a new OEM cylinder and piston, or buy an engine out of a wrecked bike. It looks like you'll get out for around $500 either way. Or roll the dice and get this set for $79: http://www.ebay.com/itm/BURGMAN-400...ash=item3d1a614be5:g:b9IAAOSwxfNXNh6Q&vxp=mtr

BTW, the gasket set and 83 mm piston from aliexpress are for the 2003-2006 400, and won't fit the newer bikes.

Edit: On second thought, I'd be all over that Ebay cylinder and piston- only 7000 miles on it and it looks pretty clean. With shipping under $100. A couple of gaskets and another few hours of work and you could be back on the road for under $150. And the broken ring is a pretty rare problem- normally the 400 is a very reliable engine- I don't think it will happen to you again.
 
#15 · (Edited)
Yeah makes me sad too to have this happen at such a young age. Broken Rings & Busted Things.
It reminds me of Elvis Presley, Jimi Hendrix, Janice Joplin, Buddy Holly, Ritchie Valens, J. P. Richardson(The Big Bopper), Otis Redding, Michael Jackson, and so many others!
 
  • Like
Reactions: gec343
#33 ·
I have driven vehicles where the manufacturer's recommendation for starting a cold-soaked engine was a shot of ether. (Seen a couple that actually had an on-board ether system!)
 
#17 ·
Great! Always happy to help another burgusa member! I hope it works for you- now just a couple of gaskets from Bikebandit and you'll be on the road in a couple of weeks!

BTW- don't hone the cylinder- you don't want to break the coating. Just wipe it clean and put on a coat of oil before assembly.
 
#18 ·
The jug and piston should be here late next week, gaskets were ordered yesterday and cost almost exactly the same as the cylinder/piston combo. Now I have time to clean up the head and throttle body. I have seen post about oil collecting in the airbox, mine had 175ml of oil in the bottom likely due to excessive blow-by after the ring broke. There is a drain tube with a check valve at the end that should take care of normal oil mist, I'll make sure that is clean and functioning before it goes back together. Too bad simple things like this are so hard to get to.
 
#21 ·
I received the cylinder and piston last week from smbikeparts (they have an ebay store). Looked good, very little wear, factory hone marks were still visible, just the carbon/varnish stain at the top of the bore. The engine starts easy and is quiet but I have an oil leak from one of the valve cover screws. I thought the old ones would seal because they are thick rubber but I was wrong. Three new ones are on the way from Bike Bandit.
Doc Wheezer-I put a longer tube on the airbox (plugged) so that I can check and drain any accumulated oil. I don't expect it ot be a ploblem now that excessive blow by has been taken care of.
 
#23 ·
Looks like you Can't Re Use the Gaskets, Again, I notice there Metal Gaskets, Would have thought you can Re Use those,,

Elliott,
 
#24 ·
Maybe, but it's rather chancey.
 
  • Like
Reactions: Elliott Larron
#26 ·
Back in the 1960's when I was running two strokes and had to decarbonize often I even painted and reused the metal head gaskets. A light coat of silver spray paint did the trick. 12,000 miles on an 80cc Yamaha and 48,000 on a 305 and never a leak at the head joint. The paper base gasket was a different story, always tore up.
 
#27 ·
Update: I've put on 10 easy miles around the neighborhood (thanks for that tip E. D., I would not have thought of that) with two heat-up/cool-down cycles, checking for leaks. Each time I stopped Coolant dripped from the area under the radiator. I removed the left side body work and checked all the joints that had been opened during the repair, all were tight and not leaking. I think the coolant that spilled while the system was being filled must have pooled somewhere and made it to the ground after stopping. I'll take a few more short rides today and watch it before the plastic goes back on.
 
#28 ·
I've got 150 miles on the "new" piston and cylinder, all fluid leaks have been taken care of, very happy with the results: Instant starts every time, smoother running (less mirror blur), faster (pretty quick to an indicated 95 mph, straight roads were never that long before), no oil in the airbox as yet.
I thank everyone for your help.
 
#29 ·
Great news and well done. Thanks for posting about this.

On the note about why your piston ring broke on such a young engine...that's an interesting one. Piston ring breakage on a young engine is usually due to incorrect break in and may indicate either too fast, or too slow break in was used. Both of those techniques can cause piston ring 'hot spots', stressing the pistons rings (although too slow run in is more likely). This metallurgically changes the surface of the rings and damages the cylinder bore coating, and causes uneven heating of the piston rings each time the engine is run. However, piston ring breakage is not always as a result of incorrect break in. It could just be a faulty ring was produced at the factory, but this is less likely these days as the cause of a failure. zcarnut, not suggesting you didn't run it in correctly, you seem to know your stuff, but just saying what we know to be the cause in most cases. You may have just been unlucky. Examination of the cylinder bore and rings by an engine specialist can determine the exact cause if you were interested.
 
#30 ·
Thank you Quantum Mechanic, I appreciate your explaination and experience. Of the 9000 miles on this engine I only had the scooter for the last 2000. It was bought from a dealer so the history is unknown. The top ring was thin and the cross section looked nothing like the one that came with the replacement piston. The groove was also wider than it should have been. The ring was in three pieces when I took the cylinder off and a short section was stuck in the groove, looks as if two broken ends might have overlapped in that wide groove. That's where the worse bore damage was. Wide groove and thin ring caused by??? Ring flutter?
 
#31 · (Edited)
Wrong top ring? It was too thin and had too much play in the groove? No wonder it broke. Seems like it must have been a mix up at the factory and the wrong top ring got put in. The second ring (1.01-103mm) is thinner than the top ring (1.21-1.23mm). Maybe they had a second ring in the top ring grove, or an oil rail in the top groove, who knows? Did you mike any of the ring parts to be able to tell?
Anyway, it's history now. Glad your riding again!
Cheers!
 
#32 ·
Yup, sounds like either a factory error or a ham-fisted idiot previous owner error. The second ring (the scraper ring) is very often made of iron, and is particularly brittle. If it were an oil ring in the compression ring (first ring) slot, then I'm not surprised it broke. Probably a factory error since the bike only had 7000 miles on it when you got it.

Good job, and I'm glad everything worked out!
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top