I've been reading but still have a question.

[QRFan]

I took my bike in to have the carbs cleaned up,rebuilt ,whatever. Although I've ridden the bike some,it sat for ten yrs prior & appeared to need new rings- blue smoke.The mechanic purchased new gaskets,rings,had the head sent off to clean off the glaze & whatever else they do. I asked him about bearing replacement etc.I wasn't comfortable w/his answer & since I left my book w/him I've been looking here for answers. He told me that there are no rod bearings on my bike that the rods just attach w/ a pin on top? I asked about cam & crank bearing ,main.he told me that the crank bearings are pressed on at the factory & if u have to replace them u may as well get a new crank ,,,blah blah blah......He also said no sense replacing the ones where the cam rests,,,,,, Now my question is,,,,,,,,,,,,,,am I getting accurate info or is he blowing smoke? I am NOT a mechanic .the bike has 57k.It's a 1979 xs1100 special ,one owner before me.It didn't knock or anything like that before I took it in. Do you think I should have these bearings changed or leave well enough alone?

[oseaghdha]

If it was not making bad noises before, it's probably ok, but getting on a bit in mileage.

To change the crank bearings, you have to spilt the case= a lot of $$ if you hire it out. And yes, there are rod bearings.

Either there was a communication failure or your mechanic is uninformed.

[bikerphil]

Engine has replaceable crank and connecting rod bearings. They are not pressed in, they are just half shells. The rods do attach to the piston on the top with a pin, but use bearing shells to attach to the crank. Now the cam doesn't have replaceable bearings. Usually the head is junk if the clearances are beyond limit. The crank is usually ok to re-use unless it's scored. Cranks are dime a dozen on eBay. Hard to tell about the condition of the bearings without seeing them, and they ain't cheap. HTH

[ccogswel]

I'll try to answer it. But there will be a Guru for sure or someone to chime in that knows this for sure but I'll take a stab at it. There is I believe rod and crank bearings. They are not pressed on. The rod bearings can be replaced by removing the rod caps. The crank bearings can be replaced by tearing the case's apart as I believe they sit in the case's when put together. There is no cam bearings to say. The cam sit's in the head. That is it. Of corse it has caps that bolt down over the cam and sometimes if you over torque them they can starve that part of the cam for oil. It sounds like your mechanic doesn't know all what he is doing when it comes to these old bikes.
Now you said the bike had sat a few years. Sometimes the rings can stick in their groves from the old oil and carbon build up. Now you can try this as I haven't tried it myself and don't remember anyone here saying they done it but maybe someone here has and I missed it. But if you had been reading like you said you have then I'm sure you read about this stuff called "sea foam" You can pour in your gas or oil, and from what I read off the can the other day it said you can pour it into the intake of a running engine to help free pistons rings that are stuck and to clean carbon build up. You just have to do each cylinder. After you pour it in when it's running shut it off. Let it sit for a few minutes then start it back up and let it clear out. It said to do it in a well ventalated area. It's worth a shot and a whole lot cheaper. But I'd say you just need to ride that bike to clear it out. When I first got my bike running it smoked like a freight train. But after a few trips up and down the rode it quit.

Well good luck!
I know there will be someone here to better answer your questions.

[QRFan]

That helps a lot

So in your opinion should I have this mechanic split the case while he has the head & jug off & check the lower end of the motor or just let it go since there has been no probs until now? I only want to do this once but I also understand sometimes if its not broke don't fix it. I need good advice. Thank you for the input.

[QRFan]

thx again

I tried the seafoam & it fixed my compression problems. I truthfully think the smoke lately was white from gas not blue from oil but since I've been working a lot of longhours the past year I decided to take the extra money & invest some into my bike.I figured if i went ahead & had new rings put in it would remove all doubt.The jugs & head are already off the bike & he showed me how the cylinder walls were smooth & glazed over,,,,,,,,, he has been trying to show & explain as he tears the bike apart & then i plan to be there when he puts it back together...I appreciate all the info he shares however I am still uncertain what to do w/ the lower end. I don't know if he just doesn't want to hassle w/ the bottom end or if it really is unnecessary. I don't like to question someone's advice but I want this bike to be ready to go & dependable when it comes out of the shop.

[HobbyMan]

IMHO, I would not let this mechanic split your cases. You would be better off doing it yourself. Sounds like he is uniformed about your bike. I believe that there are a lot better mechanics out there.

[ccogswel]

How many miles does it have?
Do you know if the previous owner rode it hard? I mean very HARD.
That you know of was it ever run low on oil?
I'd say you would be alright to leave it.
If you have your mechanic do the work he may mess it up.
There are members on here with over a 100,000 miles on their engines with no rebuilds and still going strong. Your call. If it were me I'd leave it.
If you want him to do anything go and print out in the help section or what ever it's called I can't think of it right off hand but anyway print out all the work on how to do the 1st & 2nd gear dremel fix. Give it to him. That will probably be the most important thing you could do while your this far into it. And you don't have to tear the case's apart to do it. You could have him under cut or back cut the dogs on all the gears to prevent the slipping gears that are common with these things.

[QRFan]

lmao

I would not let this mechanic split your cases. You would be better off doing it yourself. Sounds like he is uniformed about your bike. I believe that there are a lot better mechanics out there.
Today 12:47 AM

that describes why i'm getting this sick feeling I'm getting in my gut........

[QRFan]

57k

No the previous owner was my father & he never abused the bike.He just got to sick to ride & it sat for a long time (10 yrs)before it was put back on the road. Before he passed away he told me it needed the carbs redone. After I inherited the bike,It sat for a while again until I had the time & money to start fixing it. I've already had it to 3 different places( all highly recommended),trying to get the bugs out.It sat 2 more yrs between the 2nd mechanic & this one. Now I know why dad did not have the carbs fixed, he didn't know anyone who was capable of working on them. I would love to be able to do this myself but I feel as if I'm taking on calculus w/out the background in Algebra or trig. Thx for the tip about the 1st & 2nd gear dremel.

[prometheus578]

Leave the crank and rod bearings alone. Probably nothing wrong with them.
As he already has the head and cylinder off... just let him proceed with what he's doing.
Odd, though... I thought standard sized rings were no longer available, but I may be wrong.
Let the mechanic finish up... but next time, ask our permission first before you take it to a shop.
Everything that the mechanic is doing, you could have done yourself. We've talked people through tougher problems. And if they could do it.. so can you.

Plus, it's a lot cheaper that way.

[QRFan]

but next time, ask our permission first before you take it to a shop.
Everything that the mechanic is doing, you could have done yourself. We've talked people through tougher problems. And if they could do it.. so can you.

lmao ,ok Thx for the advice.

[TopCatGr58]

Hey Prom,

You can't get the original sized pistons, and I don't think the original sized rings, but you can get the 1st oversize, and then file down the end gaps to that they will fit within the original bore.

QRFan, be sure to ask if he MIC'd/micrometered the cylinders to check if they were out of round, beyond spec for HONING!? If within spec, then he should be able to hone them..break the glaze, and with the new rings do a re-break in procedure to get it the rings to seal/seat better, no leak/oil smoke!

Make sure he's putting in new valve seals, and at least laps the valves and seats, vs grinding new faces on both! Make sure he reads the chapters on setting the timing chain and cams up properly, remind him that the engine/crank rotates BACKWARDS...CW viewed from the left side so that the proper tension is put on the cam chain, and slack is at the front for the tensioner to press against....otherwise, you'll end up like Crazcnuck's bike with a bunch of bent valves!!

I did a little big bore kit on my 81Sh after it had sat for 9 year with a busted trans with an estimated 50K miles... my odometer broke at 997 and I never replaced it! Just put new pistons, rings, bored, wrist pins, and above valve lapping and seals work, did NOT touch the bottom end, NO NEW crank or rod bearings, has been running just fine for many years, and 10+k miles with a fair amount of HARD running, so like you said, it should be just fine! Only 10K miles because I just use it for fun stuff, not a daily runner!
T.C.

[prometheus578]

but you can get the 1st oversize, and then file down the end gaps to that they will fit within the original bore.

Yeah, that I know about.
But I find it doubtful that too many shops would do something like that.
Stuff like that's fine for individual owners to do... but for a shop... to many things that could go wrong.
And you know... if something engine related, (but unrelated) ever happened to the bike, the first thing the customer is gonna cry in court is, "... because the mechanic put in the wrong rings!"

[QRFan]

so far

He has cleaned up the pistons - every little nook & cranny- they look almost new . He had the cylinders honed& then "cross hatched"(not sure if correct term)..... He hasn't picked up the head from the machine shop yet,the work they've done so far didn't suit him so I'm hoping that he really is as particular as he would lead me to believe. Yes you can get the orig rings from Yamaha.1 dealer told me no,,but another was able to order them 78$ each set. I called back & forth btwn the 2 dealers to find out why one said yes & another said no they were discontinued & unavailable,,,,,,,I was afraid i was being sold after market parts for a high price when Bike Bandit has them for 54$ set. Bottom line,1 dealer(John's) went to the effort of looking up the part number & searching using YMS (yamaha's system)...the other in Chillicothe just did a search for the rings using fish finder. When I gave the part number to the (Chillicothe) dealer ,he found he was also able to order the parts too.

Here's the part number for anyone who wants it 3J2-11610-00-00 . The following link is for Yamaha's parts catalog. http://www.starmotorcycles.com/star/parts/home.aspx

Thank you guys for all your advice..I'm starting to feel better w/your support & after talking to the Mechanic again today.BTW_He asked who I'd been talking to . LMAO Maybe I'll finally get some sleep tonight Feel like I'm waiting for one of the kids to get home .

remind him that the engine/crank rotates BACKWARDS

I'll give this info to the mechanic ! Thanks to everyone.I'll keep you posted.