How Did Gearbox Oil Get Into the Fuel System?

Unfortunately MG/Piaggio decided to try and sweep the problem under the rug, rather than doing a recall. So many of the dealers are clueless. Below is a cam box removal video Pete did to help you get an idea of what’s involved and whether you want to try the job yourself.

Thank you for that video, it's priceless! That looks straightforward enough. I take it the answer to signs of damage lies in that cambox. Gonna drain the fuel tank and then consider following that video. If that's the conversion job than I could do it myself. If it's not too late damage wise. Learning as I go along..

If you've never been inside an engine before it's a fairly major undertaking. Not trying to put you off, just making sure you understand. Certainly your bike, which will require either an 'A' or 'B' kit, (As I said, post up a picture of the inside of the rocker cover and I'll tell you which.) is one of the simpler ones to rollerise as the heads don't need to come off but you still have to ensure that you maintain the cam timing correctly whilst swapping the camboxes.

If you wish I can supply the required parts for you, direct from Europe, for probably a lower cost than you will be able to purchase them in Canada. Once rollerised, and the few other essential maintenance items are carried out, there is no reason your bike shouldn't be reliable. My shop has done well in excess of two hundred rollerisations now and of those we have had two subsequent failures that can be categorically sheeted home to failed tappets and two more that failed for no reason I was able to ascertain, (Mind you they were stripped by their owners so I didn't get to do a forensic examination during the strip down.). One thing that is absolutely certain is that the longer it is left the higher the risk of further damage.

Also be aware that after rollerisation the bike will need to be tuned and re-mapped. To do that you'll need the Guzzidiag suite of tools and some form of manometer for balancing the throttle bodies and before you attempt that it is vital that you understand how the W5AM ECU works on these bikes as fiddling about with the throttlebodies without knowing what you are doing can be very expensive! Note also that many so called Guzzi shops still, even after the system was in production for thirteen years, don't know how to tune a W5AM Guzzi so entrusting this to the sort of shop that would connect the gearbox breather to the tank filler drain is probably NOT a good idea.

Whilst your idea of simply riding the bike to death might seem superficially attractive the fact remains that even if you buy a newer roller motored machine there will still be work required to get it up to speed. Most notably the need to grease the swingarm and shock linkage bearings but it too will need tuning properly as they rarely leave shops well tuned and, now being second hand, there is no way of checking without close examination, as to whether the throttle bodies have been monstered by a shaved ape.

I'd say rollerise the beast you have. We can help you through the process and you'll end up far more confident and with a far deeper understanding of your machine than if you simply buy another one.

I really appreciate all the info and help Pete and everyone else! I'll get back on the above. It's 1 am and got a quick question. I'll go talk to the dealer that likely caused this today. They're really the only one I can get the bike to in my region. There may be another option which I'll look into. The gearbox accumulated a mixture of water, some fuel and naturally the oil FOR A YEAR. So this came to the surface just days ago and I realized things were much worst when I couldn't shift anymore around the block as that crap was pouring out the top. Considering months of contamination and storage what's the likelihood of there being damage to the gearbox from this fiasco? From what I can gather so far the rest of the beast should be ok. Will have a chat to see what the options are and then I'll try to find an even better one. Night from Montreal!

There is quite likely to be rust- whether it is in critical places or not .....
The water in their may have had the air boiled out or absorbed into the oil which will have reduced oxygenation and therefore the amount of rust but ... without stripping it and inspecting ... who knows.


Ideally the shop that did that repair needs to take responsibility for a strip, inspect and rebuild of the gearbox. You need to push that, good luck?

Stripping a Guzzi gearbox requires a big garage so that you can store the frame, engine and bodywork safely whilst you work on it. So if there was no other problem and the gearbox still shifted easily (when full of oil) I would adopt a 'running in apporach' with frequent gearbox oil changes to allow all the surfaces to smooth down.

Pete Roper wrote:

Bizarre!

The only thing I can imagine is that somebody has connected the gearbox breather pipe which usually just goes up and loops up under the tank venting to atmosphere to the fuel tank breather and heat cycling has drawn fuel into the gearbox somehow.

My thought exactly, no other way this could happen.

airbornebaby wrote:

I really appreciate all the info and help Pete and everyone else! I'll get back on the above. It's 1 am and got a quick question. I'll go talk to the dealer that likely caused this today. They're really the only one I can get the bike to in my region. There may be another option which I'll look into. The gearbox accumulated  a mixture of water, some fuel and naturally the oil FOR A YEAR. So this came to the surface just days ago and I realized things were much worst when I couldn't shift anymore around the block as that crap was pouring out the top. Considering months of contamination and storage what's the likelihood of there being damage to the gearbox from this fiasco? From what I can gather so far the rest of the beast should be ok. Will have a chat to see what the options are and then I'll try to find an even better one. Night from Montreal!

Hmm, yes. The length of time the gearbox internals have been submerged is an issue. The fact that it stopped selecting is also not good. It's a shame as the 1200 8V six speeder is basically bulletproof, really, in thirteen years I don't think I've ever had to open one up and have several spares sitting on the shelf gathering dust. Quite literally, as you can see by the pic I posted.

Yes, definitely worth approaching the shop that screwed it up but could you trust them to put it right? If their 'Mechanic' doesn't understand a breather what hope would they have of rebuilding a gearbox correctly?

Airbornebaby not sure if you joined the Ontario Guzzi Riders group, lots of help and friendly rides. (Ontarioguzziriders.com) Also Carlo at Corsa is an expert he did the roller conversion on my old 2012 Tenni.

I plan on removing the fuel pump tomorrow with the goal of changing the fuel filter. This makes sense and it was suggested. I've never done that before, there are no instructions in the service manual (missing my Kawi, Haynes and for dummies manuals) and I haven't found them online. Any advice on how to go about it? You know instructions for a caveman

The OEM filter would take over 5 weeks to get from local dealers in Montreal. Haven't found a part number but it seems the Mahle KL145 could do the trick. It's available on Amazon.ca, link below, and the shipping is fast but it doesn't confirm the compatibility. Is it the right one and a good choice? Any suggestions for clamps/tools? Seeing different stuff online. If there are better options I'll pay up to get it from another country.

Mahle KL 145: [You must be registered and logged in to see this link.]

That filter will work. My GRiSO had the Mahle KL-145 in it when I replaced it.

No special instructions, or tools, required. I used regular hose clamps when I reassembled it. Don't overtighten the pump fixing screws when you reassemble it. 6 Nm is the torque spec.

Airbornebaby have you found the workshop manuals on this site?

I just did thanks to you lcjohnny. Wow what a resource! Had been looking for more books, stuff online.. I'm going through it right now.

Pump is out. A KL-145 is already in there. Gonna order that now. I can see Oetiker clamps and just plan on using side cutters to get them off. Seeing 11.3 mm clamps online so from what Beetle wrote I'll likely just get some from the hardware store. Washing the tank though I was surprised to find a lot of water flying out that fuel nipple. I figured it was getting into the tank but found out it's designed that way. That was the one connected to the gearbox. So you can imagine the water that accumulated over time as it rained and I washed it over a year. Til it burst out at the start of this new season. It's unbelievable!

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Pete you wrote  "Most notably the need to grease the swingarm and shock linkage bearings"
It's something that I've felt I should tackle next time I do a Winter upgrade and service.
Is there a tutorial on how to go about that ? The videos and tutorials on rollerization were invaluable !

Nah, but it's all pretty straightforward.

Paul Brice did a walkthrough you may find helpful:

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2 questions. Is that plastic thing part of the battery drain? And is the condition of the wire on the right something I should fix ASAP? I've never worked on the electricals before but it's something I want to learn. Got a friend that could help out. But if it can wait I'd leave it for now. Been doing the work that was suggested. Found the canister job had already been done. I plan on tubing both tank nipples to the ground, sides & away from the rear wheel.

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Errr? Which plastic thing? There seem to be several!

As to the connector boot? Just tape it up. It's the engine temperature sensor plug, it's unlikely to get water in it and short out simply because of its location. All the plastic boots break up over time because they're basically shite plastic. I have to say though, at least in Oz, the fact they're all rooted rarely if ever seems to cause problems.

Sorry I meant the rubber boot in the first picture. I found it just sitting there underneath the battery box, it's not connected to anything. Any ideas where it might go? Or garbage. As for the wire I'll tape it up.

Does your neutral indicator light work? Do you have to pull in the clutch to get the bike started? It looks like it might be the neutral light connection.

The light works, I don't have to pull the clutch to start. I'm sure it's no big deal but I'm curious where it's meant to be. I'll go through the manual and pictures and hopefully can spot it.

Spare part from the factory

Annoying thing is it looks very familiar but I can't for the life of me think what it connects to....

Is it part of the evaporative canister kit?

Don't think so, that has no electrical connection.