knocking and pinging

[toymechanic.]

First off I always put the highest octane fuel the station has, in the motorcycle!

I have a bad knocking and pinging, under acelleration, around 2000 -3500 RPMs. I also have a hesitation between 2000-4000 RPMs still I have had the carbs apart ten times everything is clean all the passage ways are clean. I've tried bigger and smaller main jets. I've tried bigger and smaller pilot jets. I have checked the timing with a timing light and the timing seems to be right on the mark!
Since the timing can not be adjusted what might my problem be. It runs great over 4000 RPMs. I have performed a cylinder leak down test and I have 2% leak down at 100 psi. All four cylinders have 130-140 psi compression. Spark plugs are burning very black! The only thing that has made a difference is having the jet needle raised .125 of an inch. I can atleast ride the bike with the jet needle raised, without the jet needle raised, it won't even rev up.

'82 GS1100GL, stock exhaust, stock air box with a K&N filter element.

Would poor ignition cause this and if so, where can I buy replacement aftermarket ignition components? I have not yet ohmed out the signal generator or the ignitor or test the coils. How do you test the coils?

[toymechanic.]

Could it be bad fuel?

[Gary Lich]

Maybe air leaks in the carb boots or o-rings from taking them off so many times.... (but that does'nt explain the black plugs). Also check that you have a good seal between the K&N and the air box and the rest of the air box seals are good too. These bikes are real sensitive to these things.

[toymechanic.]

I have misted water all around the boots while it was running & sprayed carb cleaner all around the boots. No change in the idle!

[flyingace]

That's an interesting combination, knocking and pinging with black plugs. I'm assuming the plugs are black and dry, as in sooty. One symptom indicates running lean (pinging), the other running rich (plugs).

I can only guess your pinging is related to ignition timing. Have you actually done a check with a degree wheel to deterimine if your spark is occuring at the right point before TDC? Almost sounds like the advance is stuck.

Maybe the carb people will have different idea.

[83'GK]

I would guess that you have an intake boot/O-ring leak, even though the water shows none. You have attempted to remedy this by raising the needle, but with the leak, it is falling out of suspension causing your plugs to go black. It does not take much leak to disturb the ratio, and does not take much 'lean' to make it ping, especially the 2 valve engines..

[SqDancerLynn1]

I had problems with my 850 pinging It was the intake boots causing the problem. REMOVE them from the engine, examine them close & replace the O rings

[earlfor]

The problem may in part be due to using too much throttle while being at too low of an engine rpm in too high a gear. I can make any bike ping and rattle, just by going WOT in 5th gear at 1500 rpm. :-) I would take some bets that youre not letting enough rpm build before shifting to the next gear. Might try running each gear up to about 4500 before shifting to the next one.

Earl

[KEITH KRAUSE]

Like some other say, we're getting mixed signals here. Rich AND lean symptoms?
I'm also a little confused over your words: "it runs great over 4K", but you also say that it wouldn't rev at all until you raised the jet needles 1/8".
Jetting depends on throttle position more than rpm and raising the needles wouldn't be the sole reason the bike now revs. Extremely lean mixtures will still allow the bike to rev. The revs would just be slower to return to idle.
I don't know the carbs history, but if the jetting was stock, then raising the needles is a mistake. 1/8" is a big increase in fuel. If you believe the carbs are in otherwise stock condition and all the little parts have been assembled in the correct order, then put the needles back to stock position. Most common reason for CV carbs to not accept any throttle above idle is one or more diaphragm assemblies not installed right or possibly torn/cracked/leaking. Only takes one carb to cause this.
Also make sure the primary and pilot air jets in the intake side are clear/clean.
Since you believe the timing is correct I think your pinging may be related not to a lean condition, but maybe this rich condition has been around long enough that you're getting carbon deposits built up in your cylinders that are burning red hot and causing some pre-ignition. At least the black plugs and pinging would make sense then.

[toymechanic.]

Hesitation gone!

I figure out what the whole problem is. Thank you all for trying to figure it out. Here is what the problem was. Never having Suzuki carbs apart, I put them back together like they came apart(wrong, some one else had them together wrong). When I raised the needle an 1/8" by putting the plastic spacer on bottom, compared to the metal spacer being on bottom, it helped. That was the whole problem the P/O had the metal washer under the circlip and the plastic spacer and spring above the circlip. SO when I put the pastic spacer under and the metal washer over I was close to being right. The spring goes under too. How I discovered this was a friend was over Monday night and I was telling him about my hesitation and things I had tried to fix the hesitation. So I grabbed a set of carbs that I had bought off of Ebay for parts (to show him what all I did) and when I removed the snapring and discovered the spring of them was under the plastic spacer, I said that might be my whole problem. SO I went and looked on the microfiche and sure enough the spring goes under 1/8" plastic spacer and the 1/8" plastic spacer goes under the circlip and the metal washer goes above the circlip.

I made the change last night and took it for a test drive and low and behold no more hesitation. YEE HAW It'll pull a wheelie now.

LESSON LEARNED: Never trust that anything you are working on is together right unless you see an exploded view!!!

Thanks again to everyone for helping!!

[KEITH KRAUSE]

I figure out what the whole problem is. Thank you all for trying to figure it out. Here is what the problem was. Never having Suzuki carbs apart, I put them back together like they came apart(wrong, some one else had them together wrong). When I raised the needle an 1/8" by putting the plastic spacer on bottom, compared to the metal spacer being on bottom, it helped. That was the whole problem the P/O had the metal washer under the circlip and the plastic spacer and spring above the circlip. SO when I put the pastic spacer under and the metal washer over I was close to being right. The spring goes under too. How I discovered this was a friend was over Monday night and I was telling him about my hesitation and things I had tried to fix the hesitation. So I grabbed a set of carbs that I had bought off of Ebay for parts (to show him what all I did) and when I removed the snapring and discovered the spring of them was under the plastic spacer, I said that might be my whole problem. SO I went and looked on the microfiche and sure enough the spring goes under 1/8" plastic spacer and the 1/8" plastic spacer goes under the circlip and the metal washer goes above the circlip.

I made the change last night and took it for a test drive and low and behold no more hesitation. YEE HAW It'll pull a wheelie now.

LESSON LEARNED: Never trust that anything you are working on is together right unless you see an exploded view!!!

Thanks again to everyone for helping!!

Not to toot my own horn, but your cure was mentioned in the middle of my previous post.
With any carbs that you don't know their history, check that all the little parts are correctly assembled. PO's make all kinds of mistakes that can drive you nuts. The most common mistakes is with the jet needle/diaphragm assembly.

[toymechanic.]

Keith,

You saved me a lot of headaches and time.

[KEITH KRAUSE]

Keith,

Yes you shouldn't toot your own horn. Because in a post a month or so ago about my hesitation I mentioned putting the 1/8" plastic spacer on bottom and no one had the presences of mind to say that it goes on the bottom. I not trying to be an ******* or anything because I am thankful for everyones help on this site. But that would have saved me a lot of headache and time.

Hmmm. OK.
First time I've ever received a negative because I mentioned a cure to a members problem.
I'm not sure about this other thread you mentioned or if I responded to it, but it's easy to miss a word, or a few words during the course of a thread. I answer a lot of technical threads and try to retain info as I browse and try to come up with something helpful. In many cases it's difficult to follow.
As for this 1/8" spacer that a PO installed incorrectly, not many here, including myself, have an "exploded parts" diagram burned into their memory. On some models, yes, but not all. So it would be easy to not suggest the correct cure in that threads case.
If you ever read any of my posts, I have a habit of preaching about the basics to troubleshooting problems. One of those basics I commonly mention is to never trust a part that you don't know the history of. In the case of carbs, with their multiple components, you should always check what you have against a trusted diagram or other info. You have to know this before continuing.
So I don't know if I'm one of those members who somehow made your problem harder and took longer to find simply because something was missed or something wasn't mentioned, but nobody's perfect. Sorry. I guess.

[flyingace]

Keith,

Yes you shouldn't toot your own horn. Because in a post a month or so ago about my hesitation I mentioned putting the 1/8" plastic spacer on bottom and no one had the presences of mind to say that it goes on the bottom. I not trying to be an ******* or anything because I am thankful for everyones help on this site. But that would have saved me a lot of headache and time.

Dude,
This is a free forum with people willing to give you advice out of the goodness of their hearts. Do you really think it's reasonable to EXPECT someone to give you the right answer first time every time? Get real.

[earlfor]

Aw hell Keith, I've given the correct answer, had someone refuse to use it and do something else and have it still be my fault when the bike didnt run. LOL
Your average is a helluva lot better than average. :-)

Cheers!

Earl


[QUOTE=KEITH KRAUSE]Hmmm. OK.
First time I've ever received a negative because I mentioned a cure to a members problem.