Anyone tried to change connecting rods by himself?

[snatch]

Hi everyone, that's my first post here (unfortunately, it seems that if I had come across tha forum earlier I would have prevent myself from many nasty situations..)

As an owner of 2 steamers (a '94 Mikuni carb'ed and a '98 Keihin carb'ed) and after spending hundreds of hours fixing minor or major things myself (even though I'm not a mechanic) I thought this time I could go a little deeper and try renewing all 3 con rods by myself.

So, the question now is simple: provided that I have already 'experimented' on de-assembling my '94 engine (that was a blown engine, the whole bike was purchased for spared parts), are there things beyond my knowledge that  I should know? One thing I 've learned for sure is that "taking apart" is always easier than "putting together"..

Thanks for taking time reading that post, I have to say that a lot of people here seem to know lots of stuff about steamers. In fact, I got myself smiling in threads like the one for Nology coils (I use the PVL of my '94 spare, they 're by far better than the newer english ones, before that I had already purchased a couple of new ones for 160€ each!) From now on I 'll take a look over here before buyng anything for my steamer!

And if anyone could provide me with any links for buing those con rods online, it would be much appreciated. (Price in local dealer in Greece is 190€ for each rod. I bet I can find better than that.)

[Mustang]

My question is why do you have to renew the connecting rods ?

[snatch]

Lol mustang, yes u 're right..

I wouldn't do that for fun of course. I get a nasty sound when the engine warms up. The mechanic that heard it told me that it's only one of the rods that needs replacement and that the problem is bound to be on its upper connection to the piston. Since I 've already heard how a blown tiger engine sounds like, I trust him (it sounded hell worst than this one)

But since I'll do the job, i thought I should replace all 3 of them.

[Mustang]

you are aware that in the alternator the cush drive bolt breaks off and makes a hell of a racket ....................like a rod knock  :shock:

http://www.bikebandit.com/houseofmotorcycles/triumph-motorcycle-tiger-885-carbs-serial-number-71698-and-below/o/m6913
Bike Bandit . com

Rods are $133 US dollars and the bolts and bearings are available too .

[nightrunner]

Yeah make sure its not alternator rattle (DAR) first.  DAR will make noise at low RPM but go away as you raise RPMs.  A worn rod or pin bearing will clatter at all RPM's

I have never rebuilt a M/C engine but have done a few cars.  Its usally not necessary to replace rods, just bearings.  But if heavily worn, you have to machine 0.010 to 0.030" off the crank journals and then use proper (thicker) rod bearings to make up the difference.  If the crank journal is not too badly worn you could get away with just new rod bearings.  I see from Mustang's link that the Tiger does not use a replacable upper rod bearing.   If that is where its worn out as your mechanic says, then ideally you would replace the rod and the pin (Gudgeon pin) as a set so you'd have both new mating surfaces.   Also if they are not clattering, don't mess with them.  If it really is just one cylinder, I would just replace that rod.  However if it requires machining the crank, then go through and do them all.

The best way to learn is by doing and you're obviously doing that.   Get the factory service manual and the Haynes manual if you don't have them.   Its cheap insurance.  Mistakes in the crank case can be costly.

Good luck with it

[snatch]

First of all, thank guys for your help.

Mustang, I recall having already suffered that alternator bolt failure 4-5 years ago, but I think the noise was constant, regardless of whether the engine was warm or not (I get the noise after 10-15 minutes of driving, either in a cold day or a hot one). But maybe I'm wrong, so I 'll have a look at it before doing anything else. But, mostly, thank you for that bikebandit.com link, 133$ (~85€) for each rod is beyond my best expectations (as I already told you, it's 190€ each at the local dealers store!)

@nightrunner. Thanks for the workarounds, it would be a good scenario having to replace only a couple of bearings. Right now I don't have a service manual, I do have the parts catalogue however (it's a small zip file, if anyone here thinks he could find it useful I'd be happy to upload it here, if it's not against any rules of course.)

I'll keep you guys informed with my progress, probably I'll start during this weekend. If u think I should post some photos, just let me know.

[Dr. Mordo]

Photos of any job are always a good idea.  That way if anybody else tackles it they have the photos to see what they are getting into.

[snatch]

So, it took me some time to make up my mind and start, but I 'm finally into it.

Here's my invaluable co-assistant, Persa, very useful when I ran out of rags for cleaning my hands (just kidding..)


By snatch_uni8, shot with COOLPIX L4 at 2008-05-16


By snatch_uni8, shot with COOLPIX L4 at 2008-05-16


By snatch_uni8, shot with COOLPIX L4 at 2008-05-16



I felt lucky when I saw that alternator bolt broken, as Mustang had said in the first place..


By snatch_uni8, shot with COOLPIX L4 at 2008-05-16


But since I was already there with the engine on my desk, and two mechanics had already heard the noise generated by it, claiming that it's bound to be a con rod, I had to go deeper and check.


By snatch_uni8, shot with COOLPIX L4 at 2008-05-16

The middle con rod was in a mess, its bearings where so distorted that they could actually rotate around the con rod (a couple of "teeth" should prevent that but they were f***ed up). It's obvious that the crank has to be smoothened.


By snatch_uni8, shot with COOLPIX L4 at 2008-05-16


By snatch_uni8, shot with COOLPIX L4 at 2008-05-16


By snatch_uni8, shot with COOLPIX L4 at 2008-05-16

I guess I can't invite my girlfriend in that room for a while..


I 'm waiting for the ordered parts from bikebandit, until then things stay that way. So if anyone wants more or specific photos please feel free to ask.

[Mustang]

Love the assistant , big furry fellas only want to help

[Stretch]

Eew.  Spun a bearing.

[John Stenhouse]

Brave fella, when that sort of thing happens I call in the cavalry :lol:

More power to you Snatch

[nightrunner]

So you're sending the crank to be turned down 10 or 20 thousandths?   I think you'll be in good shape with the rebuild.  I assume the con rod is otherwise OK?  Please keep us posted.  We dont hear of too many folks tearing down a steamer engine.

Be very careful in extracting that broken bolt from the alt.  New ones are not cheap.  Suggest you have a machinist do it.   Also, go with higher grade bolt when you assemble it.  IIRC the stocker is DIN 8.8 which is pretty good already.  But I found DIN 10.8 in that size and used one of those.   Also check for any rotational play between the shaft and the vane.  If the splines jiggle a bit then the new bolt will break as the old one did.  The tiny amount of play causes the bolt to slowly tighten until it breaks.   The companies that make treadlocking compounds also make compounds that are designed to take up the space in worn keyways and splines.  Its about the only decent fix I can think of and its what I did.

That's a fine looking helper!