Hi guys,
new member, first Guzzi, novice mechanic here and already have a number of questions.
- I have just had delivery of my '14 Griso and already notice an oil leak on the left side of the bike. I came back from a 40/50 min ride and I noticed a cloud of smoke due I think to oil ending up on the exhaust. I inspected the bike and initially it looked like was coming from somewhere around where the cylinder barrel meets the block toward the back of the motor. I read online there could be a number of reasons for this and got to work on the bike today. I took the tank and the side covers off and inspected more closely and noticed a rubber pipe/hose (is it call breather hose maybe?) is in very bad condition and it appears the leak is coming from there, but I know little about mechanics and close to nothing about this engine. Is anyone able to confirm it is indeed plausible that the leak comes from there? it look like that rubber pipes conect the cilinder head/rocker box to breather box at the front.
- on the right side of the breather box there is a hose going back to the airbox. Where this connects to the airbox, there seems to be quite a lot of oil and dirt and the hose does not really look in good condition. What does a breather box do, what is that pipse bringing back to the air box and do you guys suggest to replace that hose too or is fine as is as long as it stays in place?
- I notices another rubber pipe coming from the right side of the block more or less next to rear brake (is that the gearbox?) which goes up and around to the left side and does not connect to anything? Any idea if that is supposed to be like that? or does it need to go in a canister or else?
Thanks you very much in advance for all the knowledge you will want to share here!!
GRiSO ( and most of the big Guzzi’s) breathe a lot of oil vapour then let the oil separate from the blow by and drain back to the sump.
The GRiSO breathes from those hoses on the cam wheel covers at the back of the cylinder heads up to a separator box behind the steering head. From there oil drains down to the back of the sump and vapour is routed to the airbox. The separator box also has a cap covering a pipe that is not used on that model.
Because there is so much oil vapour being moved about by those big pistons, a loose or split hose or cap will leak very generous amounts so the hoses need to be in good condition if you want dry feet and tyres!
Also if you fill the engine oil level above halfway on the dipstick the engine will create so much oil mist that it will overwhelm the separator drip into the airbox and foul the two throttle bodies. This is a bad thing because the oil gum will block the airways making throttle synchronising almost impossible. It is not a nice job removing the throttle bodies to clean the gum out 
.
The gearbox breather runs up to the back of the fuel tank then loops over downwards to stop things dropping into it. They could have made a tidy little breather but that would not be so confusing.
Amazing thanks. That is very informative. I guess I will find the parts then and replace them.
Why does the oil vapour need to go into the Air box if it creates so many problems? Wouldn’t be better just to drain elsewhere?
And is the gearbox breather/hose just left hanging there? Does it just drain stuff on to the ground?
After separation the vapour should mostly be dry blow by gases that have come past the rings. This will not harm the engine so for emissions purposes it goes back in for complete combustion, as long as the oil level is not too high the airbox stays dry. Behind the battery is a 4 screw plastic plate. if you remove that you can see if the airbox is dry.
All of those gearbox breathers that i have seen have been perfectly dry at the end - i cannot imagine normal engine heat and gearbox action driving anything that high lol
Hi Griso Pizzo. If you send me the part numbers of the left and right rocker cover breather pipes I will check if the are the same as those used on the Norge or Stelvio. If they are, I have have stock of them in the UK. I had them made for me as the cost of the original parts is extremely high. You can PM me. Cheers Phil
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Thank you all! Phil, i sent you the part number. I have seen the prices of original parts and they are extortionate (north of £65!!). Gutsi bits seem to have a generic part at a fraction of that (~£10).
Best!
Hi, I’m afraid the Griso does not use either the Norge or the Stelvio pipes so I cannot supply. It will be worth trying the Gutsibits versions I think. Cheers Phil
Thanks Phil! Ended up ordering original parts from Stein-dinse. LH and RH + the rubber pipe for the vapours going to airbox cane at 140£ circa. Ouch!!! The ones on Guzzi bits did not have the right diameters so i preferred not to risk it.
I think that some people on GRiSO Ghetto bodged it with ordinary oil-resistant pipe but (as you know) there is little room around or under the tank so options to run straight hose and gentle bends are V limited
