Removing crankshaft/camchain pulley nut on LM2...

[Dukedesmo]

Further to my LM2 piston/valve moment I am wanting to remove the camchain pulleys to check a couple of things. I have the required 4-point socket to release the castle-nut but, as a newcomer to Guzzis, I need to find a way of holding it all whilst I undo without breaking anything.

Is there a recommended method or tool to hold the whole assembly whilst I undo the 3 pulley retaining nuts on the camshaft, crankshaft and oil pump?

These;

[Vasco DG]

Are the connecting rods still in-situ?

Pete

[Dukedesmo]

Are the connecting rods still in-situ?

Pete

Yes.

[Bob Wegman]

I remember reading here one time that someone (maybe fotoguzzi) removed the sump and wedged a wood block between the crankshaft and engine case to hold the crankshaft.  I've never done it but just thought it may be useful to you.

[fotoguzzi]

I remember reading here one time that someone (maybe fotoguzzi) removed the sump and wedged a wood block between the crankshaft and engine case to hold the crankshaft.  I've never done it but just thought it may be useful to you.

that was me and it work fine in a shade tree manner.

[Kiwi_Roy]

Put the bike in top gear and put your foot on the brake, yes you can do it

[Dukedesmo]

I'm not particularly happy to lock it through the gearbox/rear wheel because I can see that potentially damaging the gears, I was thinking of placing a rod (possibly wooden?) through one of the conrod little-ends so that it stops against the crankcase, as I know of people doing this on Ducati engines. I don't know if that was what Vasco DG was getting at by asking about the rods being in place?

However for Ducati engines there are specific crankshaft holding tools designed for this kind of work - and I do know of engines being damaged by the required torque when trying to hold it by other means, so I wondered if Guzzi have such a tool.

I can probably rattle it undone with a power tool although I still need to hold it securely for torqueing it back up afterwards, but mainly I don't want to cock it up and cause any (more) damage...

[fotoguzzi]

you could make a tool/bar that bolts to the timing cover holes and a pin or bolt going thru the slots in the cam gear. or if tranny is off it's easy to lock the flywheel in place.

[MotoG5]

On my G5 I removed the starter and placed a wooden wedge between the fly wheel starter ring gear and the transmission case. Used an electric impact to remove the nut. The wood wedge held the crank well enough to get the nut re-torqued. No damage, the bike ran another 40K after the timing chain tensioner upgrade before I sold it.

[Vasco DG]

Stick a gudgeon pin in the little end to protect it, slide a steel rod through the gudgeon. Rest rod on wooden blocks on case, brace rod against blocks, undo crank nut and oil pump nut, cam nut can be rattled off.

Pete

[pehayes]

Old fashioned 'shade-tree' technique.  Drop the piston half way. Remove spark plug.  Feed in and fill the cylinder with "rope" perhaps 1/4" diameter.  When you can't feed any more rope, go to work on the crank nut.  The rope can't compress and therefor the piston can't ever reach TDC.  The rope won't scar or damage anything.

Patrick Hayes
Fremont CA

[Vasco DG]

Problem is he's got the top end off Pat.

Pete

[chaoselephant23]

Another option is sticking a big flat head screwdriver through the flywheel inspection hole in between ring gear teeth. Place the screw driver at the top/bottom of the inspection hole when installing/removing the nut respectively. To avoid damage to the timing inspection hole, I'd hold the screwdriver when removing/installing the nuts. And wrap the screwdriver in electrical tape to avoid steel on aluminium contact. This method was given in Guzzi's hydro CAM recall procedure.

[canuck750]

If you have the flywheel and ring gear on there is a simple tool available from MG Cycle with a few rows of corresponding teeth that mates to the ring gear, the tool is retained on two of the engine case to transmission studs.



This tool is handy for securing the flywheel while torqueing it down as well as other assembly jobs when you want to lock the crank or cam (via the cam chain or gears).

http://www.mgcycle.com/index.php?main_page=product_info&cPath=80&products_id=332

[mtiberio]

If you have the flywheel and ring gear on there is a simple tool available from MG Cycle with a few rows of corresponding teeth that mates to the ring gear, the tool is retained on two of the engine case to transmission studs.



This tool is handy for securing the flywheel while torqueing it down as well as other assembly jobs when you want to lock the crank or cam (via the cam chain or gears).

http://www.mgcycle.com/index.php?main_page=product_info&cPath=80&products_id=332

Guzzi made this tool. A VW beetle tool also works. Or you can place a rod through the cam gear and into the hole in the case behind it.

[Chuck in Indiana]

Another option is sticking a big flat head screwdriver through the flywheel inspection hole in between ring gear teeth. Place the screw driver at the top/bottom of the inspection hole when installing/removing the nut respectively. To avoid damage to the timing inspection hole, I'd hold the screwdriver when removing/installing the nuts. And wrap the screwdriver in electrical tape to avoid steel on aluminium contact. This method was given in Guzzi's hydro CAM recall procedure.

This is Guzzi special tool GU blah blah blah.  Pretty much the same as a bent up coat hanger for the transmission reassembly tool that works fine, too. Oh. Costs a lot less. (Guzzi content)

[canuck750]

This is Guzzi special tool GU blah blah blah.  Pretty much the same as a bent up coat hanger for the transmission reassembly tool that works fine, too. Oh. Costs a lot less. (Guzzi content)

Problem with the coat hanger is I can't seem to keep blue paint on them

Cheers

Jim

[jabberwocky]

I find that my little cordless impact driver zips it right off, no need to lock the crank. Then when re-tightening the nut, just put you foot on the brake with it in gear. I can't remember the torque value, but it's not that high.

[Dukedesmo]

Thanks for the advice. 

I've removed the pulleys using the rod through the little-end method, took some force to 'crack' the two big ones but no dramas.

I wanted to check the crankshaft woodruff key which is fine and to see what cam is fitted so at this stage it was not much more to do it.

Camshaft has a 'K' stamped into the end of it, no other visible markings - is this the stock cam?



The only thing I found that is not quite right is that the cam pulley has lightly scraped the casing, don't know if this is 'normal'?

[mtiberio]

Those are machine marks from when the camshft retainer mating surface was machined at the factory.

Show/look at the side of the lobes. Will show weld up if cam modified that way

[Vasco DG]

The 'K' designates its at factory B-10 'Production Race' cam. It's actually nothing special but is more aggressive than the stock 'Lawnmower' cam. With 30 year old, early edition, valve springs you have your 'Smoking Gun'

Get new, decent, springs and exhaust valves, service the heads, I think you have a decent chain tensioner in it so you'll be good to go.

Pete

[Dukedesmo]

The 'K' designates its at factory B-10 'Production Race' cam. It's actually nothing special but is more aggressive than the stock 'Lawnmower' cam. With 30 year old, early edition, valve springs you have your 'Smoking Gun'

Get new, decent, springs and exhaust valves, service the heads, I think you have a decent chain tensioner in it so you'll be good to go.

Pete

Thanks, no doubt there was some 'operator error' with some over-rev but as you say the cam + springs + HC pistons didn't help.

I'm rebuilding with Gilardoni 88mm pistons (lower), new valves & springs so hopefully things will be good.   

[Vasco DG]

There are hundreds, probably thousands, of older Guzzis running this set-up. Do as you suggest and you'll be golden. No 'Special Stuff' required.

Since the top end is off and the valves have kissed the piston it might be worth throwing a new set of big end shells in just on the off-chance.

Pete

[Dukedesmo]

OK thanks.

On another note, I've just received the 88mm Gilardoni kit and, yes the cylinders fit into the crankcases as stated but the pistons are heavier; 525g compared to 485g for the old pistons.

The Gilardonis are claimed to be the same weight as stock pistons so maybe my old pistons are lighter than stock? Will the extra 40g per pot make it shake itself to bits?...   

[Hahnda]

What about the pins? I think the pins are lighter weight than stock.

[Dukedesmo]

Actually the Gilardoni pins weigh 95g and my old pins weigh 90g, bare piston weighs 385g and my old piston weighs 355g.

[Hahnda]

I thought they were lighter???

This is from the HMB site.
--------------------------------------------------------------------------

Cylinder Kit, 88mm bore. Complete set including cylinder, piston, piston rings, gudeon pin and circlips.

Cylinder upgrade Kit for 850 Le Mans, 850 Le Mans 2.

Our upgrade kits are machined to fit the slightly smaller bores in the engine housing of these 850 cc models. Cylinder kit can be used without further modfications.
Gudeon pin is lighter than the original one. This compensates the weight of the heavier 88mm piston in this kit. No rebalancing is required.
---------------------------------------------------------------------------

[Dukedesmo]

Maybe OEM Guzzi pistons are heavier than mine which are 'Mondial' high-compression pistons? - although having a 3mm higher dome I wouldn't think they'd be much if any lighter than stock?

Problem would be that, I believe to balance for a heavier piston would require weight to be added to the crank which is not so easy as removing it. But it's a bloody big crank so maybe it can tolerate a few extra grams? and who knows if it was ever perfectly balanced before anyway? 

[Chuck in Indiana]

Maybe OEM Guzzi pistons are heavier than mine which are 'Mondial' high-compression pistons? - although having a 3mm higher dome I wouldn't think they'd be much if any lighter than stock?

Problem would be that, I believe to balance for a heavier piston would require weight to be added to the crank which is not so easy as removing it. But it's a bloody big crank so maybe it can tolerate a few extra grams? and who knows if it was ever perfectly balanced before anyway? 

It's really no big deal to add weight to the crank if necessary. Correct weights are in the shop manual. While you're there.. you might as well do it right.

[smdl]

I would agree with doing it right while in there.  I just had mine balanced, and the guy doing it was surprised by how far it was out.  It was necessary to add Mallory metal, and that did add a bit to the cost, but worth it, in my opinion

Cheers,
Shaun