Breva 1200 - Valve clearances.

[Motonuzzi]

I've already posted this topic on the MGCGB technical forum, so I apologise if you're experiencing deja vu :roll: .

I've just carried out the two year service at 6,300 miles (yes, I know - pathetic under usage of a motorcycle )
on my Breva 1200. I could barely get a 0.02mm feeler gauge under the rockers - on all the valves.
I'm aware that the inlet valve gap is specified as 0.10mm and the exhaust valve 0.15 mm.

The thing is, the bike has only done 4,000 miles since the last service a year ago.
This is my first Moto Guzzi, so I'm not clear as to whether the valve clearance should have become so tight after so few miles. I've always serviced engines with bucket and shim adjustment previously and don't recall the valves ever tightening up to that extent. I've adjusted the clearances as per ' The book ' and the engine is a lot more tappetty now, but seems to have regained some of its former urge.

Someone has suggested that shop mechanics may be prone to setting the clearances tighter than recommended because of customer complaints about noisy engines. I'd rather have an engine that was noisy but working properly than one that was quietly burning the valve seats :dry: .

Any ( polite ) comments most welcome.

 

[john zibell]

The tech may have set them tight, so just to be safe, check the clearances every thousand miles or so for awhile and see if they tighten up. If they do, you have valve seat erosion that needs to be addressed.

 

[Kev M]

Mine have never tightened up that fast (on my B11 or Jackal), so I'm betting tight initial setting.

I'm not mentioning all the basics (overnight cold, make sure TDC bla bla bla).

Anyway if it were me, I'd reset, then go 1-2k and then recheck... if they haven't tightened up that much again, you're probably good to go for the usual 6k interval.

 

[Motonuzzi]

Thank you for your input, people.
Just to contradict myself; I don't think I can live with the ' clatter ' coming from the engine now, so, after only 200 miles, I'm going back in already . I want to check that the clearances have stayed where I set them, and if they have, I'm going to adjust them so that they are a bit tighter. Just not as tight as I found them; say 0.05 for the inlet valves and 0.08 for the exhaust valves. I'll let you know how it goes.

 

[john zibell]

Thank you for your input, people.
Just to contradict myself; I don't think I can live with the ' clatter ' coming from the engine now, so, after only 200 miles, I'm going back in already . I want to check that the clearances have stayed where I set them, and if they have, I'm going to adjust them so that they are a bit tighter. Just not as tight as I found them; say 0.05 for the inlet valves and 0.08 for the exhaust valves. I'll let you know how it goes.

Those clearances are too tight. The valve cools when in contact with the head. If the clearance is too tight, contact time isn't sufficient to cool the valve. The factory recommended settings are good. Use them. If the slight valve clatter is too much, use ear plugs. Remember a noisy valve is a happy valve.

 

[Motonuzzi]

Noted, John. Thanks.
I may still check my adjustments; just to make sure everything is as it should be.

 

[bobbyblue]

You have my sympathy. I did the same to my Breva 1100, the tappet noise was too clattery so I checked them, to my surprise they were too tight, I adjusted them to the factory specs and now I am slightly embarrassed by the REALLY loud clatter, I'm not sure if I won't tighten them a bit again, although I am worried about burning the valves out.

 

[Guzzistaracing]

The Guzzi valves ARE loud, if you do not follow the spec, valve burning is of great danger! Live with it, it is just ment to be that way! If you have to explain the noise and you feel embarrest about it, get rid of the bike, they are ment to make a racket! You get used to it after a while!

 

[Rafael]

Last time I saw a valve clearance tighten tighten up it was time for a rebuild on my T-3. Let's hope it was a renegade mechanic setting the lash too tight in your case.

Valve clatter can be thought of as an attention issue, or a test. If your having fun flying around mountain twisties your attention is on making sure you don't fly off the mountain you don't hear the clatter then. :lol: So, if your attention is focused on the clatter your'e not having fun!

Guzzi has always been about trade offs for me. Adjusting bucket 'n shim style valves is way too much work for me, though I've never shimmed a bucket.

Another way to minimize valve clatter may try a ride on a Harley for a while then get back on the Guzzi.

Okay, I'll shut up, but one last thing. trade in the Breva for V11 California with hydraulic lifters - no bad idea. First time I heard or didn't hear a CA with hydro lifters, I thought the engine was about to blow up. Till someone explained to to me...

One more thing, never mind, no wait - think agricultural equipment! inch:

Highway 12 Idaho, here I come! Can't wait till next month!

 

[Motonuzzi]

O.K. O.K. I geddit Stop throwing stuff !
I now push the ear plugs in a bit more, and I'm thinking of re-fitting the louder 'silencer' ( I took it off because of the dreaded popping ).
I've done a couple of hundred miles since adjusting the valve clearances and the engine seems fine.
I'm just relieved that I didn't leave it until I'd clocked up 12,000 miles, as per the service schedule. Who knows what damage could have occurred?
I'm hoping to do a run to Scotland and back during the next couple of weeks, so that should give it a reasonable workout. Maybe I'll post a couple of envy-inducing photos .