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**MartyA** · 08-30-2003, 11:36 PM

Pinging is premature detonation. Assuming everything else is correct, the cause is usually bad gas, or octane lower than recommended. If the gas is good, then it is a timing issue, your spark is happening too early. Do you have a noticable loss of power? A less likely cause is a way too hot engine. And a remote cause is if the pistons were scraped clean recently, small scuffed projections on the crowns could cause the gas to pre-ignite. Generally the carbs are not the cause. (Can a VERY lean condition cause a ping?)

If you have not tried it yet, get some 92 octane in there and try that. In case it is just a case of bad gas, don't buy it from the place that you got the last tank.

One other thing, are you sure it is pinging? Could the Hy-Vo chain be rattling or valves ticking or center stand ringing on the exhuust or something else making a noise that sounds like pinging?

**graybird78** · 08-31-2003, 12:12 AM

carbs

Marty; have tried high octane gas ,helped some what.have checked all other suspect areas.pretty sure its detonation. only happens at wot. ride normal no problems.

**pgg** · 08-31-2003, 04:44 AM

Have the plugs got small black spots on the white insulater? If so, retard the timing 3 or 4 degrees then see how it runs.

**MartyA** · 08-31-2003, 07:34 AM

I agree timing is the next thing to check. Did this suddenly happen, or has it been there?

Before you check the timing be sure the centrifugal advance is clean and rotates freely. Mine was gummed up and not working properly a few years ago. And see if someone has removed and replaced the bolts holding the timing plate. The 80 has special bolts with heads that sheared off when the correct torque was applied at the factory. If those have been replaced someone might have the timing off.

Thinking of carbs, need a guru here. Is there enough of a difference between 110 and 120's in #2 &#3 that would cause this? That might indicate a lean condition, but would that cause your pinging? Is there a LOT of carbon in the combustion chamber? That might be getting hot enough to cause pre-ignition.

Try a throttle chop and see what the plugs look like.

**TopCatGr58** · 08-31-2003, 08:30 AM

Hey there Graybird,

I have an 81SH, and it, too was supposed to have that mix of jets, but straight from the factory, they were 110's across all four. The idea(so I'm told) was to richen the center two cylinders to keep them running cooler since they "might" not get air cooled off as well as the outer 2, but apparently Yamaha abandoned this rationale early on, not sure why the manuals still have this ?erroneous? info.

Yes, run the high octane stuff!!! Secondly, what plugs are you running?? They might be too hot a plug, especially in the summer, and after running the bike a while, you might be getting too hot, so that pre-ignition is happening??

Your carbs might have been cleaned, but a bad gas tank with crud in it can dirty them back up very quickly. Drain your tank into a white bucket and look for residue/rust and dirt particles , bet you'll find some/lots. You may need to recoat/line your tank? Then you'll want to reclean your carbs, put inline filters on your fuel lines. Checked your air filter lately??

Your floats sound like they may be set a bit too rich, not to mention uneven, so you'll probably want to even them out, and probably set them to the .906 spec. to start!! Can you get to your idle/pilot jet screws, or are the brass caps still in place?? If they haven't been drilled out, then the pilot circuit may be clogged or not as thoroughly cleaned as it could/should have been. They are capped off at the factory and preset. I drilled mine out using a very small bit, be careful not to drill too far or too hard,just till you get thru the 1/8" cap, then I put a sheet metal screw into it, then a pair of lock jaw pliers, and then tapped the pliers with a light hammer to pull the caps out, applying some penetrating oil/spray to them first!

I agree with Marty, you will need to monitor your plugs after you get all this other stuff done!! Good luck!

**graybird78** · 08-31-2003, 12:32 PM

re-carbs

Hi guys. I'm running recommended plugs .maybe I should run colder plugs.Have been using 91 octane gas.timing still has original bolts in it. this condition has been there for quit some time.I just try to not use wot.just bothers me it exsists. I will check timing and related for function.not sure about float height though. They are uneven.would adjusting idle mix screws make any diff.looked at screw tips in carb bores and they are diff height too. Their is some carbon buildup on intakes . will let know what I find .Just need to adjust floats properly. thanks for replys.

**TopCatGr58** · 09-01-2003, 08:25 PM

Hey there GrayBird,

Rob Reil, the carb GURU down in Atlanta gave a little seminar at last years NC rally, and showed that the Pilot Circuits do have some input thru much of the RPM band, even when the mains are kicking in.

Like Marty said, I'd look closely at your vacuum advance plate, spin it by hand, make sure it turns easily, doesn't snag or feel any drag on it when you turn it, and that it returns to original position. Also, check your vacuum line, look for holes, cracks, and test it, pull it off at the carb and apply some suction and make sure the plate will turn!! Is it attached to the right port, the one on the carb body, not the intake boot??

What do your plugs say, check out the tech tips, there's some nice pictures on what they should and should not look like!!

Finally, you can still get octane booster to add to your gas. We can get 92 around here. Are you using a cheap brand, or major brand, from new station, or old one with possibly contaminated tanks?!?! Good Luck.
T.C.

**graybird78** · 09-05-2003, 11:01 PM

re carbs

well finally got to look at carbs really good. problems i encountered when taking carbs apart were float pins did not want to come out of floats. #4 float pin brass insert for float was missing. #2 & #3 carb float pins were partially sticking due to brass inserts in floats were corroded. #3 brass insert for float actually fell apart in 4 pieces. only good float pin & brass insert was #1 carb. idle mixture screws were still factory sealed. upon removing them #4 was missing small metal washer that goes on after spring to seal "O" ring down in bore. none of the idle mixture screws were the same number of turns out. float levels were all wrong. book calls for .906 - floats were actually higher i think than spec. but none of the floats were even the same drop. reset the floats to book specs. cleaned carbs thoroughly with carb cleaner & lots of air. everything seems to be clear. did check ignition vacuum advance & seems to be functioning properly. does not appear to be sticking or binding. vacuum line to unit is ok. will hold vacuum. vacuum line to carbs all routed properly. while carbs were off did look in intake valves do have carbon deposits on back of valves. problem that i'm trying to fix is pinging at wide open throttle. maybe i'll try colder spark plugs or octane boost & see what that does. any other input or advice would be GREATLY appreciated. i'm going to stick with this problem until i get it fixed. other than that bike seems to run fine.

**fusionking** · 09-06-2003, 03:14 PM

Ok my question is , even tho it's wide open is it when you first hammer down on it or after it has built up speed and RPM,s? The reason I ask is cause when you really think about it the vacuam advance probably won't do much when the butterflys and slides are totaly open but when the butterflies are open and the slides are partly open would be differant. Play with unhooking it and see how it reacts if you haven't already done that. Vac advance is usually a part throttle cruise thing. P.S. have you tried seafoam or Berryman B-12 in it yet? (good stuff)

**MartyA** · 09-06-2003, 04:09 PM

That's a good question. Years ago when it was not unusual for cars to ping, it was usually at the lower RPMs. You could get it to ping even more by opening the throttle up at lower RPM.

I'm wondering if that carbon is part of the problem. I know pieces of carbon in the combustion chamber can get hot and hold that heat long enough to preignite the fuel.

Someone on this forum had a ticking sound they thought was coming from the top of the engine, like a cam-on-spacer sound. Turned out it was an exhaust leak. So my quesiton is are you sure it is pinging like you have bad gas, or are you actually hearing something else, like maybe a loose Hy-Vo chain? Can the clutch housing 'ring?' Or something like that?

Just thinking out loud...

**pgg** · 09-06-2003, 04:50 PM

If you've installed a free flow filter, it'd be advisable to rejet richer than standard. A hot motor and lean mix will cause a ping alright. A temperature gauge running directly off the cylinder head is useful for jetting and fine tuning the motor too. Useful when fitting a 4-1 and free flow filter or such like. If the jetting is even slightly lean, the motor runs wickedly hot. With a very slightly rich mixture, my 78e runs at about 110-115 deg celcius at 60 mph cruising. My 'hotted up' xs with higher compression and flowed head runs at around 135 deg c cruising. On a hot day, even with the right jetting, the gauge needle can get pegged at plus 150 deg c in stop /start town riding. I've felt a small "ping" down low at that temperature. You should be able to fix your "pinging" motor by experimenting with mixtures and small timing adjustments. It doesn't sound like you've got serious detonation problems - and anyway the alloy won't start liquifying until around 700 deg c. If the motor starts flowing onto the road surface things could get a little bit concerning though.

**graybird78** · 09-07-2003, 09:04 PM

re-ping

well ,when the motor is cold runs ok .But as motor warms up knocking or pinging is more predominent.I'm sure it's a heat issue.I do have a uni air filter installed ,to which i was told is free flowing. this knocking or pinging only happens under heavy engine load.motor in neutral rev engine to red line no noise. the best octane gas I can get is 91 around here. Iwork at a gas station so I know not to buy gas at low volume pumper .I have certain stations that I buy gas from cuz i know they do good volumes of gas. heck my station alone gets 3 deliveries a week. I have been using ngk plugs.only the heat range listed in clymers. I do have dyna coils installed to plug gap to .035. Carbon in cylinders is about 15-20% . have been using techron in gas to help with carbon ,but does'nt seem to be helping .so just switched to something new. It's called BG mil 3000. It's for carbon deposits. will see how it works. Have used carbon remover before called BG 44 k but at $24 kind of exspensive. Also makes bike stink out exhaust. Will do what ever it takes to fix this problem cuz I love to be Xsive.to good of a bike to give up on.

**dntemp_ca** · 09-08-2003, 10:49 AM

Graybird78
Hello, Michael
Try taking the left side cover off and glance at the vacuum advance when you're riding. If the advance is chattering (moving back and forth wildly), it will resonate and make a metallic pinging sound. The cause of the vacuum chatter could be a leak in the vacuum hose, carb boot, dirty carbs, etc, etc. ...OR... as I saw in another recent thread, an unusual noise could be caused by a dry drive shaft assy. Although I have had the rear wheel off and lubed the final drive hub, I'm going to look at the whole drive shaft assy next because my bike also has a knocking/pinging sound like yours ... seems to be coming off the left side of the bike. It drives me crazy!@#$ Three summers of riding and I'm still looking for it! Otherwise it runs like a champ! Let me know if you solve yours. I'll do likewise with a post to the forum.
In efforts to solve the noise, I have:
-replaced the vac adv hose
-replaced carb boots
-tested vac advance diaphragm
-cleaned carbs
-cleaned & lubed centrifugal advance mechanism
-lubed rear drive hub
-changed exhaust header gaskets
I have no noise when tooling around town, but when the engine warms up and I get up to hiway speeds, it rattles. Same as you, I can rev till the cows come home in neutral or on the centre stand and there's no noise.
Ride smilin'

**TopCatGr58** · 09-08-2003, 08:18 PM

Re: re-ping

Originally posted by graybird78
well ,when the motor is cold runs ok .But as motor warms up knocking or pinging is more predominent.I'm sure it's a heat issue.I do have a uni air filter installed ,to which i was told is free flowing. this knocking or pinging only happens under heavy engine load.motor in neutral rev engine to red line no noise. the best octane gas I can get is 91 around here. <snip>I have been using ngk plugs.only the heat range listed in clymers. I do have dyna coils installed to plug gap to .035. Carbon in cylinders is about 15-20% . <snip>Will do what ever it takes to fix this problem cuz I love to be Xsive.to good of a bike to give up on.

Hey there again GreyBird,

As I was told, all engines run leaner as they warm up, and with your Indy Filters, you are running a little more leaner than stock! And the leaner you run, the hotter it will run! Jetting guide says to go up 2 sizes for Indy filters, and 2 more for 4-1 or better header pipes, but to subtract 1 size when combo. Jet sizes go up 2.5 increment, so from 110, you could probably go to 115 with no problem. I've got both above, and run 117.5.

Also, you're running hotter coils, so you possibly could also try a step colder plug! You stated that the higher octane gas helped a little. After trying the other changes above, wouldn't hurt to try some octane boost. But, final thought, how many miles on your engine? What's your compression? Could you be hearing piston slap under heavy load due to worn rings/cylinders with too much clearance?? I don't think the carbon buildup should be that much of an issue, but I'm not an engineer guru, it might be retaining excess heat leading or contributing to detonation, but I think if you get it richer, and better octane, you should be able to eliminate that ping!? HTH, Good Luck.
T.C.

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