Author Topic: Pinking (pinging)  (Read 9140 times)

Offline a10gf

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Re: Pinking (pinging)
« Reply #30 on: 07.11. 2009 10:49 »
This must be a major irritation!

Still my only suggestion, triple check magneto and auto advance, things may happen as rpm rises, may look ok when setting timing and at idle\low rpm. Maybe borrow and fit a set in known perfect working condition, if only to completely eliminate the ignition as the possible cause.

Had uneven L\R timing and points 'bouncing' at higher rpm, not found before doing this and this

e

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Offline a101960

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Re: Pinking (pinging)
« Reply #31 on: 07.11. 2009 11:31 »
Quote
This must be a major irritation!
You have hit the nail on the head! The problem is I have had the mag and the A/R unit checked out by an acknowledged expert and he said they were both O.K. Now, that is not to say that he could be wrong, but the chap has a excellent reputation as being the best that there is for magneto work. I am reluctant to mess about with it myself on two counts. I do not really have much mechanical aptitude, and I therefore do not have the confidence to carry out this kind of work which would require a high degree of accuracy. I am beginning  to think that there is something fundamentally wrong with either the mag or the A/R unit, the problem is where do I get an a accurate diagnosis from?

Online RichardL

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Re: Pinking (pinging)
« Reply #32 on: 07.11. 2009 13:16 »
John,

It might help if the members offering suggestions knew who your expert was. I realize that you are being appropriately diplomatic in not mentioning the name, but others here may have expereince with, or even be friends with him. No one would deny that you have have been most repectful of his name and expertise. Nevertheless, there are folks here with a lot of experience who might have other opinions of him. Otherwise, knowing the person, they might be able to pose the right questions for you to ask or, even, intercede on your behalf. (I would not be among those who know the man, being that I'm in Chicago.)

Richard L.
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Offline a101960

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Re: Pinking (pinging)
« Reply #33 on: 07.11. 2009 13:40 »
Richard,

No secret about who the man is: Tony Cooper. Tony has a enviable reputation and the general concensus is that he certainly does a good job on magneto overhaul and repairs. As it happens I have just been out for a quick ride (not far because the sky is looking very leaden). The exhaust note has lost the sharp bark that it had before but it seems to go reasonably well. Because the forecast is not to Kosher I did not have time to ride out to my nemesis: the infamous hill that gives me all this grief ( Richard from Mintey knows it well). Anyway I did not have any pinking but the acid test will be the this particular hill. I just hope that there is some clear weather before the local authority start putting grit on the roads.

Online Triton Thrasher

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Re: Pinking (pinging)
« Reply #34 on: 07.11. 2009 13:54 »
Have you tried raising the needle in the throttle slide?

Offline a101960

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Re: Pinking (pinging)
« Reply #35 on: 07.11. 2009 14:01 »
Triton Thrasher,

Yes I have tried raising the needle in the throttle slide and to honest I could not detect any difference.

Online RichardL

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Re: Pinking (pinging)
« Reply #36 on: 07.11. 2009 14:06 »
We are going to have 67 deg. F. today in Chicago and I plan to take advantage of it.

As soon as I read the name, I recognized it from accolades here on the forum, and a search turned up a lot of them.

Richard L.
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Offline a10gf

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Re: Pinking (pinging)
« Reply #37 on: 07.11. 2009 14:22 »
Quote
I do not really have much mechanical aptitude
After having sorted out this problem, you will!
"Problems are sources of knowledge"  ;)

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Online Triton Thrasher

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Re: Pinking (pinging)
« Reply #38 on: 07.11. 2009 17:55 »
Conventional wisdom says that if you're sure the mixture isn't weak and you're sure th timing is correct at all rpm, you may be using a compression ratio too high for your engine with the fuel you're using.

Online RichardL

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Re: Pinking (pinging)
« Reply #39 on: 07.11. 2009 19:13 »
TT,

I seems hard to imagine that the 8.5:1 pistons are too much compression with the 99 "RON" petrol a101960 says he's using. Now, I'm not that familiar with the "RON" system you use in the UK. In the U.S., "regular" unleaded gasoline is 87 octane. I see that "ordinary" unleaded in the UK is 95 "RON". So, maybe this means the 99 RON is not so high in "octane" as the number implies. I look forward to being set straight on this.

Richard L.
Plan on signing up for the world-wide 2017 DISTINGUISHED GENTLEMAN'S RIDE on September 30, 2018. Watch website at https://www.gentlemansride.com for details.

Richard

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Re: Pinking (pinging)
« Reply #40 on: 07.11. 2009 21:27 »

Offline a101960

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Re: Pinking (pinging)
« Reply #41 on: 07.11. 2009 23:18 »
Richard,

99 RON = 99 octane   95 RON = 95 octane. 95 is regular petrol 99 is premium. We also have 97, and 98 and 100 octane lead petrol is on sale still at a few outlets. The problem is that it is the small independent guys that stock it, and they are becoming fewer and fewer because low volume sales make it uneconomic to stock. There is a very heavy tax penalty which makes it expensive. I always used to use it when my local filling station had it, but it is now no longer sold there.

John

Offline Josh Cox

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Re: Pinking (pinging)
« Reply #42 on: 07.11. 2009 23:34 »
100 Low Lead is easily available at any light aircraft airport, AVGAS.
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Online muskrat

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Re: Pinking (pinging)
« Reply #43 on: 08.11. 2009 07:28 »
Josh uses the enema tube to syphon his plane to fuel his bikes. Percs (sic) of the trade !
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Online Triton Thrasher

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Re: Pinking (pinging)
« Reply #44 on: 08.11. 2009 09:22 »
TT,

I seems hard to imagine that the 8.5:1 pistons are too much compression with the 99 "RON" petrol a101960 says he's using. Now, I'm not that familiar with the "RON" system you use in the UK. In the U.S., "regular" unleaded gasoline is 87 octane. I see that "ordinary" unleaded in the UK is 95 "RON". So, maybe this means the 99 RON is not so high in "octane" as the number implies. I look forward to being set straight on this.

Richard L.

I agree.  I'd have thought you'd maybe get away with "ordinary" unleaded at 8.5:1 in a 650 with alloy head.  I suspect something is making the engine overheat.

Timing should realy be checked up to high rpm with a strobe, which is a bit of a fiddle on a bike like an A10.  Points on a loose pivot can make the timing do strange things at speed.


Incidentally, isn't USA fuel rated by the MON octane number?  Which means your 87 might be our 95?

Just googled it and it might even be PON!


http://www.btinternet.com/~madmole/Reference/RONMONPON.html