General Category > General Discussion

Head Gasket woes

(1/4) > >>

wirespokes:
This 'new' G5 has been a true test of my patience. I've worked through most of the issues and have been close to the finish line a few times. Without going into the long version, the main culprit appears to be the left side head gasket.

I got the bike mid June and have been working on it ever since. It was a rolling basket case with many missing parts when the PO got it. He installed new gilardonis, but the bike would stall when warm. I'm guessing he got frustrated trying to get it running right and parked it. Five years later he sold it to me.

I thought it was a tuning issue, at least that's the place to start - valve lash, timing, etc. It would pop and spit at low throttle opening, but run well otherwise. It dawned on me that I should check head torque. I loosened the nuts 1/4 turn and it took 1/2 turn to get them up to torque.

Wa La! No more popping spitting at low throttle opening.

Gradually it started spitting again and, as before, I'd think "it needs larger pilot jets...". And then I got smart and figured I'd revisit the head torque. Sure enough, that fixed it. It had been five or six hundred miles.

So I rode to a friend's house 10 miles away yesterday and it ran perfect. He rode it around the block and it ran fine. Then an hour later I rode home. it spit back two or three times on the ride home.

The left side idle adjustment has been a bit odd, so I'm thinking there's something wrong with the head gasket on that side. My thoughts are that it's been run too many miles needing retorqued and the gasket is damaged or, hopefully not, there's some erosion to the head or cylinder.

Have you ever run into anything like this?

cliffrod:
I think I understand. 

As a new Guzzi owner decades ago with little guidance beyond the factory and haynes manual, I had similar head gasket problems on my V7 Sport after rebuilding it from a basket case. After a couple of failures (first, no or only one retorque and then 2-3 retorques) I finally decided to do the drill at least 5-6 times.  Torque to spec, run engine (not riding) until fully hot, let it cool, retorque. After 6 cycles, there was no additional gain when retorquing.   I never had a head gasket failure after that. 

A few years later, when the entire engine needed a rebuild from unaddressed chrome bore debris issues, I reassembled it and did the same thing.   No head gasket failure.

I understand doing this is excessive in comparison to what service manuals recommend, but it works for me. 

blackcat:
Is there any evidence of oil leakage from that cylinder?  Even if there isn't, I'd buy a new gasket just so you can take it off the list of possible problems. I usually torque the heads with new gaskets after three heat cycles. Also, have the valve clearances been very tight on that cylinder?

wirespokes:
You know, I've NEVER had to retorque a head gasket. I've taken airheads apart and put them back together with the original head gaskets (no retorquing) with never a problem. Not complaining - this is just new to me.

What sort of poor running problems have you had when they need retorquing? With this one it acts like it's running very lean at low throttle opening. I'm wondering if a gasket is compromised into the pushrod channel - it's not weeping at all that I've noticed.

I retorqued the left side this morning but it didn't seem to need it. Valve clearance was fine and the head nuts seemed to go back to the same position. Maybe the problem is on the other side... ?? Maybe your right blackcat - just replace them both to be sure.

Another thing is there's a lot of adjuster above the valve lash lock nut. Like the same distance as the thickness of the nut. And, while I'm on that subject, are the rocker jam nuts high strength or low grade? Mine are pretty beat up and certainly don't feel hardened. I know of other rocker jam nuts that are hardened.

cliffrod - was there any damage to the heads or jugs in your case with failing head gaskets?

Tony F:
I encountered this issue  with head gaskets on my SP1000 about 30 years ago. The gasket would compress and close up the valve clearances so it wouldn't idle. It would take 3 or 4 tightening cycles to bed them down. But no trouble with later gaskets a few years after that. It seemed like there was a bad/soft batch of gaskets in circulation. A friend of mine went through it all as well at about the same time.

Navigation

[0] Message Index

[#] Next page