Aaargh - what's broken now???

[Guest Nogbad]

I assume that with the standard crossover arrangement, a problem resulting in oil burning on one pot will give oil smoke from both cans, though it would probably be more pronounced on the side with the failure.

[Guzzirider]

I haven't topped the oil recently - yesterday I did 125 miles around the Peak District - no problems. The only significant event in the past 500 miles was the 'yellow lining' this evening. Haven't checked the oil level, but will do tomorow.

51897[/snapback]

 

 

Surprised I did not bump into you- yesterday rode over Snake Pass down to Matlock Bath (full of idiots on Jap bikes hammering it in a 30 limit past crowded streets), pub stop in the sunshine overlooking Carsington Water then back through Dovedale where the roads were relatively empty for a Sunday. The sun was shining and the scenery fantastic!

 

Guy

[GuzzBun]

I was going to say check the banjo fittings for the oil recovery system, and the breather hose from the block to the frame, as these are both well known eventual leaks.... but they would just get oil ON the engine/exhaust and make a hell of a stench and smoke burning off the hot bits.... not come out of the pipes.

 

I would still look to see if your breather hose has deteriorated and cracked, as that is a common thing after a few years of heat, and that does make a mess.

 

al

51912[/snapback]

 

Thanks - will check all those. But where does the strange noise come from - could it be the breather pipe venting under pressure?

 

Robin

[GuzzBun]

Surprised I did not bump into you- yesterday rode over Snake Pass down to Matlock Bath (full of idiots on Jap bikes hammering it in a 30 limit past crowded streets), pub stop in the sunshine overlooking Carsington Water then back through Dovedale where the roads were relatively empty for a Sunday. The sun was shining and the scenery fantastic!

 

Guy 

51920[/snapback]

 

Didn't go out until 3pm - then took the roads from Sutton Coldfield to Ilam - had an ice cream and walk about, then went on to 'something' Head (begins with M, and overlooks a beautiful valley!), then pelted back through a valley with some fantastic fast straights and corking bends, and along the Bakewell to Ashbourne road - cracking route with no straight bits - all bends, weaves and back-doubles. Stopped for a smoko in Ashbourne (a lime green V11 went by - guess it wasn't you), then slapped on down the A515 to Sutton - no caravans, no idiots (except me) and no smoke form the exhausts!

 

Guess I'll be fettling this weekend, rather than riding - unless I go and get my MGS01 from Sussex - yes - think I'll do that!!!

 

Robin

[Steve G.]

The only thing over reving [and you didn't] could do would be to tap a valve, or bend a pushrod, neither of which would cause smoke. A cracked piston ring? Don't think so, as the oil smoke would be more pronounced on one side.

The noise kind of sounds like a vaccum leak or something. Cracked rings don't usually make any noise.

A jambed or blocked pcv valve [positive crankcase ventilation valve] can cause oil to be pushed from the sump up into the top end and past the valve seals, and everywhere actually. I'm sure this engine has one. All engines from the mid seventies had to have them, heck my Norton Commando has one. Basically the system vents crankcase gases back into the airbox to be burned with the incoming air into the airbox. This could be causing the hissing sound as well.

Ciao, Steve G.

[DeBenGuzzi]

The only thing over reving [and you didn't] could do would be to tap a valve, or bend a pushrod, neither of which would cause smoke. A cracked piston ring? Don't think so, as the oil smoke would be more pronounced on one side.

The noise kind of sounds like a vaccum leak or something. Cracked rings don't usually make any noise.

A jambed or blocked pcv valve [positive crankcase ventilation valve] can cause oil to be pushed from the sump up into the top end and past the valve seals, and everywhere actually. I'm sure this engine has one. All engines from the mid seventies had to have them, heck my Norton Commando has one. Basically the system vents crankcase gases back into the airbox to be burned with the incoming air into the airbox.  This could be causing the hissing sound as well.

                                                                            Ciao, Steve G.

51944[/snapback]

that might explain the puff of smoke I got one time, I was freaked out by it but now I feel better knowing thats probably it

[Steve G.]

Talking to Mike from MPH Motorcycles at the Laverda rally a couple weeks ago, mainly about the current Guzzi engine. He confirmed that it is a very tough old girl, and is extremely rare for one to break mechanically from long use or abuse. The crankshafts on these things are made of nodular iron, very strong. The week link on this engine is the top end, and before anything blows up, she will bend a pushrod or float a valve.

Ciao, Steve G.

[DeBenGuzzi]

So put in stronger valves and do a once over on the electrical and youre set for life? Sweet I need new valves

[not_scooter_Scura!]

Great no more going for the redline, no more wheelies Man I can't have any fun on this bike now I might break something.  oh well I'll try not to think about it for now. 

51904[/snapback]

 

it's all about corneing speed DeBen,

otherwise get a supermoto as well like me.

[not_scooter_Scura!]

that might explain the puff of smoke I got one time, I was freaked out by it but now I feel better knowing thats probably it 

51945[/snapback]

 

can confirm, watched my mate redline in front of me, puff of smoke (not like a slower rich mixture smoke_ but a huge puff.

 

checked over, all good, sound good, ride home &

 

 

so keep on I hope.

[Guest davidb]

sounds like crankcase vent blockage. The crossover is one big opening inside(I opened mine and looked) so you cannot make a cylinder side judgement from the exhaust. But the fact that it happened near red line. creating a large amount of crankcase pressure (beemers do it too) I would agree with everyone too.

[jrt]

There's a small, soft-rubber vent line right on top of the spine- near the head. Check that first- it vents the oil recovery system in the spine. I pinched mine one time and when it built up pressure and blew....scared the heck out of me.

I agree with Steve- it's probably an oil recovery or crankcase vent problem- your symptoms are not consistent with a bent valve. Besides, I yellow line mine all the time and it's just fine.

[GuzzBun]

There's a small, soft-rubber vent line right on top of the spine- near the head.  Check that first- it vents the oil recovery system in the spine.  I pinched mine one time and when it built up pressure and blew....scared the heck out of me. 

I agree with Steve- it's probably an oil recovery or crankcase vent problem- your symptoms are not consistent with a bent valve.  Besides, I yellow line mine all the time and it's just fine.

51984[/snapback]

 

Thanks guys - given me plenty to look at! It's certainly not the first time I've yellow-lined her, and I have red-lined on a couple of occasions - damned if I know what speed was indicated - I couldn't open my eyes long enough to read the speedo!

 

Someone off-line has suggested it might be a head gasket - whatever, I'll give her a thick coat of looking at tomorrow. It's the noise that intrigues me - a sort of rattly wheeze when pulling hard on wide throttle.

 

Robin

[Ballacraine]

Thanks guys - given me plenty to look at! It's certainly not the first time I've yellow-lined her, and I have red-lined on a couple of occasions - damned if I know what speed was indicated - I couldn't open my eyes long enough to read the speedo!

 

Someone off-line has suggested it might be a head gasket - whatever, I'll give her a thick coat of looking at tomorrow. It's the noise that intrigues me - a sort of rattly wheeze when pulling hard on wide throttle.

 

Robin

51999[/snapback]

 

Always difficult to diagnose from a description of a sound.

 

It could be head gasket. If a head gasket is letting go, the noise will get steadily worse, and to varying degrees will always be present whilst the engine is running. If it is that sort it ASAP. If you leave it the mating surfaces will pick up damage from blow-by where the gasket has let go.

 

It might also be an air leak somewhere on the intake side.

 

Nige

[jrt]

Just for kicks and grins, check the valve lash when you go through her. Another cheap, effective, hopefully negative probe is to stick a 'magnet on a stick' down the sump (use the oil cap) and fish around for metal. I hope you don't find any.

 

I would be good to know where the noise is originating from...If it is a head gasket, wouldn't it be blowing oil out at the seal?

J