8v Sluggish - Bad Gas?

Hi all,

I have a 2010 8v that was rollerized back in 2016, but I haven’t ridden much over the past 18 months.  I started it up a week ago and was very sluggish to accelerate once moving, and took an excessive amount of throttle to start moving from a stop.  I drained the gas and put in new, but not much improvement.

Unfortunately there are no longer any “good” Guzzi dealers near me that I can take it to - any ideas on what the issue might be?  Thanks!

Are the brakes dragging? Is it firing on both cylinders? Is the air filter blocked?

Thanks Pete. No on the brakes and air filter, but the cylinder thing didn’t occur to me. This happened once before years ago and I obtained a new chip(?) under warranty.

I just started it up it again and it’s hard to tell by just listening, but the left header gets hot pretty quickly while the right header is slightly warm at best. If this is it, could this simply be a bad spark plug due to sitting around for so long?

Could be a fouled plug. Could be a damaged plug cap. Take the plug lead cover off and watch and listen for the spark *Snapping* to earth around the bend in the cap. If they were removed by pulling them up from the top the cap is probably damaged. Correct way to remove them is by inserting a long, thin screwdriver through the cooling tunnel above the exhaust manifold and levering them off the plug from below.

If the cap is damaged a temporary repair can usually be effected by smearing the crack with silastic and wrapping the whole area with electrical tape.

I took the Gris into the local shop, but they are no longer a dealer so don’t have access to the factory diagnostic equipment. However, they did confirm that one cylinder is only intermittently firing. Rather than trailer the bike to the nearest actual dealer 30 miles away, wondering if I might suggest any way to narrow the problem. My ideas:

1) years ago I had a “chip” go bad on one cylinder, which was replaced under warranty. Might I suggest the shop switch the coil/spark plug lead to the opposite side to confirm any components are bad?

2) I have purchased the recommended replacement plug caps and could just have them remove the stock caps and install these? However, if this is not in fact the problem, I would like to avoid doing this as the replacement caps are straight (no L shape) and I fear the little caps with the Guzzi logo will no longer fit and the leads will just be hanging out in the air?

3) any other ideas?

Thank you!

If you take the plug lead covers off and start the bike in the dark you will almost certainly be able to see and/or hear the spark snapping to earth at the plug tube or rocker cover. That will confirm the problem.

The way to remove the caps is to lever them off from underneath by inserting a long, thin, flat bladed screwdriver through the cooling tunnel above the exhaust manifold in the head and popping them off the plug. Not by grabbing them from the top as it is this that damages the caps.

The NGK caps will fit fine. You just have to bend the lead a bit brutally at the top of the cap to get the cover on. It's a bit cringe inducing but it works just fine and the cover will still fit.

I had a recurring problem with my 2013 (factory rollers, Beetle map, otherwise stock). The symptoms would occur right after a fill-up.

The bike would struggle to start, refuse to idle and would only run at higher RPM.

After 10-15 miles the problem would go away and the bike would run normally.

I did the NGK swap to no effect, checked the fuel cap drains and sacrificed a chicken inside a pentagram at midnight of a full moon.

Every time I thought I had a fix I would fill the tank and (sad trombone). Finally, I deleted the carbon canister and plugged the lines.

No trouble since then but... Why? Was the canister filling with gas and causing a rich condition? Plugs never looked black.

I hadn’t thought of the chicken (!), but did ask the shop to start the bike in the dark and check for arcing. If this is the problem, I gave them the new NGK caps to install. I could do all this myself of course, but hesitate to ride it home now that I know it’s running essentially on one cylinder.

This whole thing is a mystery as the problem arose out of nowhere after sitting unused for 6 months - ran fine previously.

This is what i did to my now deceased 15 GRiSO it was much improved after adding ngk red wires [You must be registered and logged in to see this image.]

Pretty! Did you drill a hole through the plug cover for the lead to exit and add a rubber surround to keep out water? (Not that it rains much in Southern California, but is currently.)

No rubber grommet . You still have to remove the cover ,I rode it in torrencial florida down pours with no issues . Those are ngk racing wire cut to fit i went to napa for the coil end terminal

A better pic [You must be registered and logged in to see this image.]

Well, after replacing the plug caps with no improvement, I trucked the GRiSO across town to a real Guzzi shop. They were quickly able to discern that I had a bad injector. Still no idea how this would happen while sitting unused in my garage for months, but perhaps starting up with old fuel in the system played a role. Anyway, it’s fixed now.

Very odd failure. The injectors are normally very reliable. Nothing's infallible though.

ICE vehicles do not like sitting unused
Corrosion grows with condensation in electrical connectors, insulators go brittle if UV can get at it hoses will go hard and modern fuel is less stable than it was 20yr ago