Excessive pinking

I've just completed a 3200 mile tour down to Spain & back. I have noticed that she pinking fairly badly when pulling strongly from the lower part of the rev range. I had put about 500 mile on her after doing the roller cam/beetle map upgrade & this was largely in wet conditions so was probably driving her a bit more conservativly.


I never run her on 98 ron cause I'm a stinge & only heard the odd pink from her before. I will pull the plugs & check colour & recheck the valve clearances incase the exhausts have tightened. She still pops a bit on overrun so will also check exhaust for leaks.

The temps were bloody hot (For a Scot) 29-32 deg & she got a fair cooking in almost stationery traffic entering dumbarton (funny smellz)

Never pinked like this before so is their anything else that could be going on?

Dont really want to be dropping it more gears to get it higher up the rev range to escape the pinking zone, especialy now that the wall of torque post mapping , is so much more enjoyable. I'm also not lugging it excessivley.


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When you remapped it after rollerisation dis you clear the trims? Also did it get a full tune up after rollerisation? TB balance etc? Something isn't right. Those sorts of temperatures are normal summer siding over here.

Oh? And are you sure it's detonation you're hearing? It's couldn't be camchain rattle could it? When you rollerised did you replace the sump spacer gasket between the block and the spacer?

Hi Pete

Not sure I cleared the trims TBH. T.B's were balanced & TPS reset & reset parameters? (Not correct term) IIRC. It's running beautifully otherwise & has never been this smooth before.

Sump spacer gasket was also done at this time & I am confident it's pinking, more evident under heavier load & lessens out as the revs climb up higher & the load lessens higher up the rev range.

Only time I really heard it before was 1st running of the year with 5-6 month old fuel a couple of years ago.

Did a fair bit on the French motorways 5k rpm for quite a few hours with no issues.

Final day was 720 miles , from Poole to Skye. Was giving it some berries on the final few miles & thats where it was most evident, although I had been hearing it most of the tour, when I was overtaking etc.

Was generaly behaving & respecting speed limits trying to protect the old license.

OK. Nothing there sounds wrong so we need to look elsewhere. Do you have ethanol in your fuel?

Thats a good point , Spain & France was mostly E10 & possibly some of the U.K too, that could be a big factor couldnt it? Also I am right in thinking if it was running lean it could also pink?

Been getting really good gas mileage out of her, loads better than pre roller/map, strangley the fuel computer says it's worse but it clearly isnt.

That's a bit odd. If you 'Re-set the parameters' that is clearing the trims so you're good there.

To be honest, while the ethanol issue may be relevant I'm thinking there is probably something else happening here as well. A bit more history on the bike might give me a few pointers?

I bought her @ 8000 miles with 1 prev owner & apart from it being badly behaved at low throttle it's been pretty much flawless. After watching your youtube vid on T.B balancing I managed to iron out the low speedy around town whiskey throttle/constant clutch feathering issue. It was a bit of a handfull TBH.

Rollered it at 12000 mile & apart from a bit of a hastle with the tps & T.B balancing, turned out to be T.B inlet manifold clamps were not very tight & sitting over the winter had not really helped the throttle cables & linkages be as loose as they could be. After a couple of hundred miles I did another tps reset & she trued up no worries.

Pre rollering fuel was giving about 47 avg on the computer & after it dropped to avg 39-40 on computer for the general out country riding I do, shes actualy doing around 57 now when I work it out. I'm light & not exactly tall so that probably helps a bit. around town it drops a bit I think.

Like I said the initial post rollering rides I did were mainly on wet roads although not all & I would have noticed her pinking. I work evey day with engines & all sorts of mechanical stuff & diagnosis & repair is what I do.

I'm interested in plug colour incase she's running lean & will give them a pull & check. Ive just given her a well overdue wash & will leave it to dry out.

Also it's always been an asshole when it's cold or even if it's been standing 30 mins after a full temp ride, first 5 mins it's a bit reluctant to pull cleanly.

I suppose recheck the basics will be the most appropriate cource of action.

One thing I will add is when I was balancing the TB's I had a lot more rod flutter on the RH cylinder , the rod in the morgan carbtune I mean, even when I swapped the tubes over it stayed on the same cylinder.

This had me wondering about inlet valve sealing effectiveness on the RH cylinder.

Prior to using it I had pulled the carbtune apart & polished the stainless rods.

OK I pulled the plugs approx 4000 miles old , here they are. Maybe slightly lean, but I look after a lot of 4cyl Yamaha outboards  that run leaner looking plugs.

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Here's some crappy borescope pics. Both cylinders look the same I'd say.

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Plugs look like it's a bit on the lean side. Have you noticed any pinging riding around home? Haven't they mandated some ethanol in all fuel there?

Hi Beetle

At the moment we have E5 here localy & prior it hasn't caused me a problem, I'm still in recovery mode from my trip & havn't hoped on it since getting back on Friday night.

I believe the last couple of fill ups were with E5 but I cant say with 100% certainty.

Also should have stated that the bike has no other modifications. Could this be caused by a O2 sensor going out of whack?

No, because lambda is deactivated in my maps.

If the TB balance is good, then it's potentially an or leak or fuel delivery issue. I think a fuel problem would create more than just pinging.

With GuzziDiag connected with a cold engine, do the engine temperature and intake air temperature agree with each other? That is, are they within a few degrees of each other?

Just checked the temps & they are within 1 deg of each other.

Interestingly on both sides the clamp onto the inlet stubs took a couple of turns to tighten them up, the LH side was showing signs of weeping the type of clag you get in the inlet tracts.

I had only recently snugged these clamps up prior to leaving, the rubbers look alright too.

Is there a MAP sensor or is injector duration worked out on the tps only? I see there is some kina barometric measurement in Guzzi diag.

No MAP sensor. The pressure reading is ambient, read from the sensor in the dash. RPM, TPS, intake & engine temperature, plus ambient air pressure, are the used to calculate injector pulse width. The TB flow rate is set on the bench, hence the "sacred" screw.

Cool , if it dries up I will go for a wee blast just incase the clamps tightening has had a positive effect.

Left field ideas
(1) the inlet air temp sensor in the airbox (top right front side) can get covered in oily gunge which seems to insulate it and upset the running. Easy to check + easy to clean (Gently)
(2) loos exhausts can clang against the head at peak bmep giving the sound of pinking - worth checking

Just taken her out for a good thrapping & not one single hint of any pinking. And I tried! , even engaged highly inapropriate speed.

Same fuel , air temp down to 12deg instead of the 29 dropping to 22 when it last did it. , & only the inlet boots tightened.

Being September in the Highlands, probably aint gonna see temps that high again for a good while sadly.

Thanks for your help guys, much appreciated.

Good news. Next summer will be the test.

I am avidly lurking, learning and taking notes. I found the clamps to the intake spigot almost loose and tightened them up. Now I Know that I also need to check the free play as I did try to evenly and minimal cable play. It might be not enough play/looseness. The Ethanol is a 10% curse here.(Texas) I CAN get leaded gas as it is used for our farm and ranch equipment and you show a permit to purchase it. I don't think it's high enough in rating for the compression of our engines.

Change the fuel filter , and check your air filter. Running low octane in hot weather is definitely asking for detonation problems. You know what happens to your stomach when you drink cheap scotch.