Engine rebuild

[e30 gangsta]

Hey guys Im contemplating either selling my really clean 80 eleven special, or rebuilding it. I need some guidance though. Cylinder #2 started to oil foul plugs. So bad that there is smoke now on startup and while driving, when I rev it up oil shoots out of the exhaust. I did a hot compression test I got 125psi.

My question to you guys is how hard is to to remove the cylinder heads while leaving the block in the bike?

And would it be worth ripping the entire top end apart to drop in that 1196 ebay big bore kit to fix the problem? Seeing as its only $150+machining+labor.

I do not want to rebuild the entire engine. I just figured installing that big bore kit will take care of my problem, give me fresh bores, fresh pistons, and I could lap and change the valve seats out while im there.

Should I even dig into the bike that far? Or just part it out? Thanks.

[motoman]

........Basicly depends on where YOUR real interest lies.

[Diskman01]

I am also looking at the big-bore kit on ebay to fix my 78's oil problem.

However! Once the Big Bore kit starts burning oil then what??

[mack]

Smoke

what colour is the smoke. Could be you have a bad valve stem seal. However the compression is pretty low on #2, what are the other cyclinder numbers. How many miles on the bike? If they are all below 145 you should do the rings. The tear down is easy, a pain in the butt for sure but nothing to be fearfull of. If you check the sleeves for out of round and find they are in spec then just buy rings and don't bore the sleeves and move up in bore diameter. Complete ring kits for all four cylinders are under a $80 us. I just did a set and my compression numbers upon a cold reassembly was 172, 155, 167 and 168. The 155 will come up and the others will go down a bit as I remember that during assembly I had some ring slippage issues and had to do it twice so the assy oil was thinner on that one.. Purrs like a cat and I'll check them all again when I get the break in oil out of it, (after 500 miles) and the regular 20-50 into it!

[e30 gangsta]

what colour is the smoke. Could be you have a bad valve stem seal. However the compression is pretty low on #2, what are the other cyclinder numbers. How many miles on the bike? If they are all below 145 you should do the rings. The tear down is easy, a pain in the butt for sure but nothing to be fearfull of. If you check the sleeves for out of round and find they are in spec then just by rings and don't hone the sleeves and move up in bore diameter. Complete ring kits for all four cylinders are under a $80 us. I just did a set and my compression numbers upon a cold reassembly was 172, 155, 167 and 168. The 155 will come up and the others will go down a bit as I remember that during assembly I had some ring slippage issues and had to do it twice so the assy oil was thinner on that one.. Purrs like a cat and I'll check them all again when I get the break in oil out of it and the regular 20-50 into it!

The color is white smoke, immediately on startup, and the other cylinders are 150+.

[DiverRay]

I'd expect valve problems more than rings with white smoke. Oil should be blue, rich is black. I would also think about the valve seals as the #1 problem, and possibly the vacuum advance mechanism leaking, and sucking in oil from a bad crank seal under the left cover.
Anything less than 80K miles and the rings SHOULD be OK, but the P.O. might be the problem...

[TopCatGr58]

Hey Mack,

I checked out the ebay link you posted in the other thread, those are NEW rings from HY company. Those are standard OEM size, not an oversize. Would be curious to see if they also have the 1st oversize ring sets available??

Gangsta, with an abused engine, it might be hard to expect the cylinders to be within spec wear for just a honing and standard rings? Like Ray stated, it's more likely the valve stem seals. I can't recall all of the history of your bike, the low comp could be too tight valve, or slightly burned valve seat. The next step to the HOT comp check would be to squirt a little oil in and see if the value increases. If it rises a lot, then you can suspect worn cylinder/comp rings. IF it doesn't rise then it's the valve/seat.

You would need to take the head off to replace the seals, you can do the lapping and reset the clearances while off, and yes, there's room to remove the head in the frame. Also a good idea to check your cam chain tensioner to see if the plunger is near/at it's wear limit, and if so, then replace the cam chain and the tensioner at the same time, for the ACCT or the MODDED manual, whichever you prefer.

And while you have the head off, you can mic the cylinders to see if they are out of round and by how much, as well as a good look at the cylinder walls for evidence of excessive wear.

Also, just want to mention about ensuring that the carbs aren't flooding and that you don't have gas in the oil, which can also cause gas/oil to get pushed into the crankcase vent and back into the carbs/engine.

Some final info, I did the smaller 1179 Wiseco BB on mine when it hit an estimated 50K miles but had sat, corroded, rusted for 9 years outside. I did NOT split the cases or plastigauge the crank/con bearings. The bike had been running alright prior to parking it with damaged 1st and 2nd gears. These bikes are known to go 100K miles, and I also knew that the bearing shells were quite rare anyways. SO....I rolled the dice and didn't touch the bottom end, just bored/new pistons/wrist pins. Have put on ~24k miles in the last 15 years, still running strong.

As for concerns about what to do IF/WHEN the bored engine starts burning oil/running low comps, it shouldn't be any problem finding old jugs to rebore, get new BB oversize rings and freshen it up again, provided the bearings are still good!

T.C.

[BA80]

The color is white smoke, immediately on startup, and the other cylinders are 150+.

I agree with TC on the valve seals. Smoke on startup is from oil leaking down on the valves through those seals and burning up on startup. It's really not a big issue but it does cause a little embarrassment to some.

Mine does it but It doesn't bother me a lot. The engine runs great and doesn't use a LOT of oil.

The positive way to look at it is automatic top end oiling.

[e30 gangsta]

This has to be some sort massive failure. Ive had valve seals go bad before, but never this much oil out of the pipe. Ill probablly rip the cylinders out, mic them see how bad the damage is and go up in bore to bigger pistons. While I'm there ill lap the valves and change the seals. Might as well since I'm already there. thanks guys.

[ViperRon]

Carbon can build up on a seal and cause the valve seal to leak. Typically in engines that have had a period of time sitting you can have a valve that remains open and it can develop a little rust and that can be the start od a build up. Valves are supposed to spin and build up can deform seals or wear them to the point that do not seal. I would suspect an issue with seals valve or guide. If you are on first size pistons and the wear of the cylinders is not bad then buy oversize rings lightly hone fine grit or a ball hone and file the rings to get a good gap is a much cheaper solution than doing a big bore kit. You will not get an enormous power gain. It is a good solution if you have messed up cylinders. There is another solution if you have one bad cylinder. You can replace the sleeves if you can find a good one. Some times they are abandoned because broken fins etc. and you can get one cheap. If you have a stove you can change the cylinder an about an hour easy.

[e30 gangsta]

A stove you mean like change out the actual steel insert?

Well I did a cold compression test. 90psi compared to all the others which are 150+ cold. Added a little bit of oil, compression shot up to 150+. Seems like its the rings.

So my question to you guys is. I basically have to turn the motor till the timing marks on the cams line up. Then remove the heads, and the barrels. And rebuild her.

I have 3 questions.

1. Can the heads and barrels be taken off with the block in the frame?

2. Is there any timing marks on the crank, incase I need to spin it for whatever reason.

3. What ring gap should I be shooting for?

Thanks guys.

[TopCatGr58]

Hey there,

Well, I normally would direct you to Catatonic Bug's website to ensure that you've downloaded the service manuals he provides, but his site currently is down, not sure if it's due to the extreme weather in that part of the country or what??

Yes, you can remove the head/jugs in the frame, the jugs are about 3" tall with I think about another 1" or so for the skirts, there is like 7-8" of clearance between the top of the head bolts and the underside of the top frame rail. There are timing marks on the crank ignition timing plate. You have to rotate the engine first to the "C" mark, then while watching the cams, rotate the crank again to position the opposing cam sprocket bolts in the UP position so you can access them first. Then rotate the crank again to end up at the "C" mark so that the remaining sprocket bolts will then be UP, so you can then remove them, and then pull the sprockets off of the cam shoulders without further rotating the cams/crank, and then unbolt the head and remove it...but you will still need to remove the cams from the head to get the head off while preserving the chain. Now if you plan on replacing the cam chain then you can cut the chain after you have removed the 2nd set of sprocket bolts and the crank/cams are in the "C" alignment position.

Now that I think more about it, if you are cutting the chain, you don't necessarily have to remove the sprockets for the disassembly, just get the crank/cams dots aligned at the "C" mark, and then cut the chain, loosen the head nuts and remove/lift up the head directly off of the jugs. You just need to be careful not allow the crank to rotate once the chain is cut, because the pistons can then come up and hit the open valves that are being held open due to the cams still in the head.

Then putting the new chain in/on, you will need to connect it to the OLD chain end, feed it in/down/around the crank....you can rotate the crank NOW to advance the chain, until you get the new ends up, and then you'll need to secure them with some form of tension retaining device while reinstalling the head to keep the chain engaged around the crank sprocket. Would be best to remove the tranny/engine pan to allow visual inspection from below anyways for a final assurance before actually joining the chain ends back around the cam sprockets with the master link that will need to be peened. And you'll need to ensure that you have the crank and cams again at the proper "C" and alignment dots when joining the chain, then install the ACCT/CCT and preliminarily setting the tension. Then you can rotate the engine a couple of times to recheck the "C" alignment timing marks before you can call it done....along with truly verifying the chain is engaged in the crank sprocket teeth. A member had their chain stuck BESIDE the crank sprocket and crank and there was enough tension/friction to allow it to turn the cams surprisingly in time, but when he actually went to start it, slipped and ruined several valves!!

Piston Ring End Gaps, top and second: 0.2 to 0.4mm standard, LIMIT= 1.0 mm/0.039in
0.008-0.016in,
Oil control rails: 0.2 to 0.9mm, 1.5mm LIMIT.
0.008in to 0.035in, 0.059in limit.
The expandable oil ring is unmeasureable.

T.C.

[e30 gangsta]

Ouch that incident has to stink with the cam chain. Awesome thanks so much for the info, I guess now I need that FSM and the torque specs and I can jump into this rebuild. This will be the first motor I rebuild So I am kind of excited lol.

Im going to do the 1196 big bore kit from ebay the $150 one, and new valve seals and lap the valves. Hopefully I can get this done under $500 with my own labor.

Also the bike is a 80, is there a better year head and or cam combination that makes more power?

Thanks guys.

[b.walker5]

Some years ago i did some research into Hasting's rings and compatible types and sizes for XS11's. I'm not sure if anyone took it further and sourced some, but emails to Hasting's at the time certainly indicated that they could supply suitable replacements in all oversizes.

Do a search of the forum to find the discussion, or click the link and email them direct. I'm sure they can help.

https://www.hastingspistonrings.com/

[ViperRon]

On the 1196 Cylinder bore kit make sure to let a high quality machine shop do the work and do not cut all the material away in one cut. You are cutting so much material that it generates heat and if the cut is too deep it will start to deform sleeves. I would suggest doing what I had done and get someone with a machine high speed hone to hone to final bore. What I got gone was by a high performance race shop locally and they charged me 225.00 If the cylinders are bored to where you have the minimum skirt of .0016 in clearance you are golden. The kit I received all pistons were exact to where I could not measure a difference and with that skirt clearance the ring gaps all fall into place to where it will not seize. This piston kit is not a high performance kit it is like original equipment and is the cheapest solution to a full renew with a small gain in power. There are specialty piston kits that have higher compression gains and if you are doing this for performance that is where you need to go

Removing sleeves is as easy as cleaning assembly turning jugs upside down on a support and putting them in an oven on 400 degrees and after about 15 to 20 minutes they will just drop out. to reinsert reverse the process and they will drop in. Much cheaper solution then boring 4 sleeves if you have one bad one. Also the sleeve may not be bad the rings can rust or stick and cause the same issues with bad compression. Also squirt some thick oil in and if compression jumps back up its rings if it does not its valves. If you find a cylinder that has broken rings and it has run this way for a while then I would suggest replacing the piston too as the ring grooves are more than likely worn.