rossoandy broken his bike again!

[rossoandy]

Note to self: Don't let Rossoandy take my bike out for a spin...

aww, let me run it in?

 

Pete, that's interesting. My great idea of a center steel gear might not be so great after all. It's not the first time. But I'm kind of surprised to be honest. Using different metals should have an ameliorating effect on the problem of galling- I thought that was caused by using two contacting soft metals. Now what am I going to do with the set of timing gears that I've had on the shelf for the last 10 years? Well, anyhow, this isn't the place and I will bow out.

 

Hope your bike is ok RossoAndy- I'll hoist a glass of wine for you.

Thanks jrt, it coulda been worse.....its a shame its happened to me twice on two different Rosso's. Makes me wonder how close the engine no's are.....hmmm I wonder if I have that info..I may have.

Maybe Luggi left his torque wrench at home that day?

But I will admit to riding the bike to within an ich of its life on accasions.....but hey its a big lowly stressed lump....isnt it?.....

I love it, the way jap bike owners keep looking in their mirrors and that big ol tracter is still there! he he just this time Rosso ran outa breath....

[slug]

aww, let me run it in?

 

In to what?

[badmotogoozer]

Rossoandy - puts the "break" back into "break in".

 

Rj

[Guest Nogbad]

Rossoandy - puts the "break" back into "break in".

 

Rj

 

 

He should never have visited that "Motoman" site.......

[rossoandy]

Heads both been off and four new valves installed, intersting to see the 'packing' Guzzi place under the valves...almost like they didnt have the right length so looked around and found some washers to stuff under emm! hmm wondering if this packing is related to the length of the valves ....

Anyway, gave valves a light lap in and reassembled the heads so ready to go on perhaps later today.

Any one got the head torque to hand? guess it be in the manual if I can find it! tappets? oh long as the heads tight and valves got lash..... oh, must look for a stocking to strain the bits outa the oil so I can put it back too...

[luhbo]

Those washers are crucial to adjust the valve springs resp. the spring load to the correct length/force. Especially in your case I'd very carefully measure and adjust things here, 'cause otherwise the valves could act as the limiter the next time you produce your bike, this way making the ecu's one obsolete.

 

Hubert

[pete roper]

Heads both been off and four new valves installed, intersting to see the 'packing' Guzzi place under the valves...almost like they didnt have the right length so looked around and found some washers to stuff under emm! hmm wondering if this packing is related to the length of the valves ....

Anyway, gave valves a light lap in and reassembled the heads so ready to go on perhaps later today.

Any one got the head torque to hand? guess it be in the manual if I can find it! tappets? oh long as the heads tight and valves got lash..... oh, must look for a stocking to strain the bits outa the oil so I can put it back too...

 

If you haven't cut the valves and seats properly the valves will fail prematurely, a 'Light Lap' will not surfice. Where were the witness marks after the 'Light Lap'.

 

The Torque for all six bolts should be 32-34 ft/lbs. Torque them again after one heat cycle and make sure to torque them dynamically. Then repeat at the first service. After that you can forget about it.

 

I still can't understand how you found the locator peg in the bottom of the timing chest. It's not a drive pin and should of sheared as soon as the cam nut came loose. Even if it didn't I can't see how it would of fallen out? Have you got any pictures?

 

Pete

[Guest ratchethack]

If you haven't cut the valves and seats properly the valves will fail prematurely, a 'Light Lap' will not surfice. Where were the witness marks after the 'Light Lap'.

Pete, I'd appreciate it if you could elaborate on this a bit. Though I've done complete valve and seat regrinds several times (had the local Pro's do it), in many cases I've replaced exhaust valves over the years that were serviceable, yet beginning to show signs of pitting at the faces. I'm riding a 4-valve single now, to which I did just this a few years ago, also replaced a spring on that one valve that didn't quite measure up to full spec. In each case, I did a 2-stage hand lap, being very careful to look at witness marks to ensure full & proper seating across the "middle" grind (sorry, my terminology is probably a little weak here, but you get my drift ), ensuring that guides were in good shape and valves well centered. In each case, all seemed well in this process and ever since. Is any part of this not correct procedure?

 

Please advise.

 

Many thanks.

[rossoandy]

If you haven't cut the valves and seats properly the valves will fail prematurely, a 'Light Lap' will not surfice. Where were the witness marks after the 'Light Lap'.

 

The Torque for all six bolts should be 32-34 ft/lbs. Torque them again after one heat cycle and make sure to torque them dynamically. Then repeat at the first service. After that you can forget about it.

 

I still can't understand how you found the locator peg in the bottom of the timing chest. It's not a drive pin and should of sheared as soon as the cam nut came loose. Even if it didn't I can't see how it would of fallen out? Have you got any pictures?

 

Pete

Don't worry Pete, there was a nice grey ring around both lalves and seats after only a few second with fine paste,and in the middle of seat too!. I more worried about the valve spring packing, I put it all back whence it cam e but I've got new valves now so will poss need adjustment. But..its all back tgether now...hmm maybe I can dissmanle valves with heads on if needs be....Anyone know about this packing in detail?

As for the pin it def didnt shear and I cant remember pulling it out and even if I had I wouldnt have laid it in the bottom of timing cover...

I have carefully cleaned the thread for this nut and loctited it on! Its done up as tightly as I dared...

 

Those washers are crucial to adjust the valve springs resp. the spring load to the correct length/force. Especially in your case I'd very carefully measure and adjust things here, 'cause otherwise the valves could act as the limiter the next time you produce your bike, this way making the ecu's one obsolete.

 

Hubert

Hubert can you enlarge on this please?

I thought it may have something to do with spring rating/length/and ensuring they do not become coilbound?

I reckon I can get vavle collars off and back on with heads on with a little imagination and a tool made up for the job.

[pete roper]

Don't worry Pete, there was a nice grey ring around both lalves and seats after only a few second with fine paste,and in the middle of seat too!. I more worried about the valve spring packing, I put it all back whence it cam e but I've got new valves now so will poss need adjustment. But..its all back tgether now...hmm maybe I can dissmanle valves with heads on if needs be....Anyone know about this packing in detail?

As for the pin it def didnt shear and I cant remember pulling it out and even if I had I wouldnt have laid it in the bottom of timing cover...

I have carefully cleaned the thread for this nut and loctited it on! Its done up as tightly as I dared...

Hubert can you enlarge on this please?

I thought it may have something to do with spring rating/length/and ensuring they do not become coilbound?

I reckon I can get vavle collars off and back on with heads on with a little imagination and a tool made up for the job.

 

Two things about the valves.

 

1.) The shim stack.

 

This is used to preload the valve springs so their seated pressure is correct. When the seats are re-cut it may be neccessary to add more shim to keep the preload correct. Most if not all big block valves are shimmed to the same height (47mm compressed height? Something like that.) but different models over the years have used a variety of springs. Most decent head shops will have a spring tester and the spring preload can be establishedwith this by compressing the spring to suit and getting a reading. Too little shim will lead to inadequate preload and a tendency for the vales to float earlier than they should. Too much, especially with a higher lift cam, can lead to the springs reaching coilbind with disastrous results.

 

2.) Cutting in new valves.

 

Whenever new valves are installed it is extremely wise to re-cut the seats to suit. Even if you get a clean witness mark in the centre of the valve mating face there will of been wear to the surface. The valve and it's seat should have a difference of a degree or so to help cope with the deformation of the valve lip when seated. If this isn't established on installation it can lead to premature wear, hot-spots and burning of the valve due to it's lessened ability to dump heat when seated. In a lazy old slug like a Guzzi motor it isn't probably going to be an issue so much as some but I'd still recommend that the job be done correctly to maximise the life of the valve and seat.

 

Lapping of valves is something that really went out with the Ark. A modern Serdi type bench will cut valves and seats accurately enough that no lapping is required, even a set of decent hand cutters will need nothing more than a quick wallop on the head of the valve with a ball-peen hammer to seat the freshly cut valves correctly. I don't think I even own a lapping cup any more? Although I do have some grinding paste somewhere!

 

Pete

[Guest ratchethack]

2.) Cutting in new valves.

 

Whenever new valves are installed it is extremely wise to re-cut the seats to suit. Even if you get a clean witness mark in the centre of the valve mating face there will of been wear to the surface. The valve and it's seat should have a difference of a degree or so to help cope with the deformation of the valve lip when seated. If this isn't established on installation it can lead to premature wear, hot-spots and burning of the valve due to it's lessened ability to dump heat when seated. In a lazy old slug like a Guzzi motor it isn't probably going to be an issue so much as some but I'd still recommend that the job be done correctly to maximise the life of the valve and seat.

 

Lapping of valves is something that really went out with the Ark. A modern Serdi type bench will cut valves and seats accurately enough that no lapping is required, even a set of decent hand cutters will need nothing more than a quick wallop on the head of the valve with a ball-peen hammer to seat the freshly cut valves correctly. I don't think I even own a lapping cup any more? Although I do have some grinding paste somewhere!

 

Pete

Many thanks f'er bringin' me into the new century here, Pete. Hand lapping of valves may've well gone out with the Ark, but then some would say that (and worse!) about Yours Truly -- and the Guzzi I rode in on, f'er that matter . . . In years past, I've found it one of those labors of love that I wouldn't ever consider trusting anyone else to do. Lately many operations that once actually required hand craftsmanship seem to've all been replaced with low-cost automated processes (that no doubt yield higher quality results in many cases) and few even remember many o' those man-machine "bonding exercises" I once took great satisfaction in. [. . .sigh. . .]

 

Up until just a few years back I'd re-face aluminum heads of singles and twins with alternating stages of wet-dry paper on a pane of glass running a stream of hose water through the spark plug hole. Why? I reckon it's a matter of pride in self reliance and not trusting anyone else as much as I trust my own work. Always worked like a champ, and I could generally get it done in less time than a couple trips to the local machinist to drop off & pick up. Ah, the bad old days. . .

[Guest Nogbad]

Agree totally about starting from a proper recut.... but I wouldn't be so hasty as to throw out a light lap followed by a check with the old marking blue. Seems a mite more sophisticated than the new "Birmingham screwdriver" method.

 

But hey, I don't have to rebuild heads at a profitable rate.

 

[Guest ratchethack]

. . ."Birmingham screwdriver" method.

That's wot they must've used to build my old A65 Thunderbolt.

[rossoandy]

Well folks all is well in Rosso land again...

 

All back together and after a 10mile run and then an oil change/tappet check/head re torque I wet for another run this tme using many more revs....but..not found the rev limiter yet!

Runs fine although idle at times a little erratic,even stalled on me at one junction. I guess I need to re set the injector bodies.linkages etc so will pay a visit to see Baldrick at Corsa in London...He got it as smooth as silk last time he tinkered with it. Idle seems a tad slower than used to be...

Now...wheres that fireblade..................

Intereresting the comment on valve seating...I agree factory valve lappng went out yrs ago but unless the valves are coated with someting during pruduction I can see no harm in a light lap to confirm visually it is seated ok. I actually poured some gasoline into the ports and looked for seepage when I finshed as a way of double checking the seats seal and flushing any possible residue grinding paste outa the port. I happy with result but a little concerned shimming under valves may not b spot on anymore..

 

I looking forward to maybe joining run out to Hastings this weekend...

 

Thanks to all my pals on here for showing interest in my drivel on here...

 

Special thanks to the sites owner for creating it.

[Ballacraine]

Pleased you have managed to redeem the situation!

 

Nige.