Can Mobil 1 2X cause Pinging?

[WetBehindEars]

I remember someone else writing this about mobil 1 around here, and I seem to recall the same thing happening when I first used Mobil 1 awhile back. In any case, I can't figure out what is causing pinging on my cycle ('75 Aermacchi/H-D 175).

Ever since I replaced the rings on my cycle, I've noticed pinging. But it seems to be about the same time I started using Mobil 1. I already switched to super from premium gas. I even tried race gas and octane boost that seems to make it go away, but is very expensive to use every ride. I thought it was an air leak in the manifold since I did put the air box on kinda sloppy, but I finally got around to putting it on good today, but it still pings.

1. Can Mobil1 2X cause pinging?
2. Do new rings have a break in period? / cause pinging?
3. How bad is pinging supposed to be before being taken seriously? I can't hear it except when I am idling, and I take my helmet off. (Although my bike is really loud).

 

[Propflux01]

You hear it at idling? if so, it ain't ping.....sounds more like wrist pin or broken piston ring if your hearing a 'ping' at idle....

 

[honus402]

1)If you changed rings, your compression ratio should be higher, requiring a higher octane fuel. That is; if you're sure it's pinging.

2) Mobil 1 is a PAO and conducts heat and NOISE much better than a dino oil. My Harleys are quite a bit more noisy with M-1, but run much cooler. Again; are you sure it's pinging?

 

[WetBehindEars]

No, I am not sure what I am talking about. That's why I am called wet-behind-the-ears.

I don't hear a 'ping' noise per se. What I hear is a rattle noise/metallic noise at idle. From what I've read that metalic sound is pinging, isn't it? Although it's usually described as happening under load not at idle.

Anyway, I've heard that same noise about 1 year ago when using mobil 1 as well, and I did the rings a couple of months ago. So the noise might have something to do with the oil.

My compression is very good for that bike year/model presently. My parts guy/aermacchi guru told me it should be between 100-125 lbs.; and mine is on the high side. (I don't remember exactly the amount of lbs. right now). So perhaps I didn't screw anything up when I did the rings, and it is in fact a loose pin?

[ June 18, 2005, 09:50 PM: Message edited by: WetBehindEars ]

 

[wileyE]

Not likely your able to hear ping on a twostroke, Mx2t wouldn't cause it. Did you measure the piston when you did the rings? it could be a bit loose in the bore and cause a little slap. Does the sound go away or get better when it heats up? If it's doing it under high load? have you checked the timing lately, I'm guessing it has points? any fiddleing with the gap can change the timing.

 

[WetBehindEars]

1. No I did not measure the piston.

2. It gets worse when it heats up.

3. I can't hear anything except a really loud lawn mower/weed wacker noise under load - the thing is one loud dirt bike.

4. I did adjust the timing yesterday and it didn't help; it was only off by like 1/12 of an inch anyway. So I doubt it's a timing issue.

5. That thing doesn't have points actually, but a cdi box - that is new incidentally.

The compression is good, so how bad can the bore be? It always had that rattle then, but more noticeable with M1. I swapped out the oil with Motul. The little rattle is still there, but not as loud however. It must be something like a ring or the bore not being all too tight. Is it still rideable like that? It's a faint noise anyway. After reading these replies, I am almost sure I am making mountains out of molehills.

 

[Cujet]

It is very unlikely that the oil would affect detonation in any way. The simple addition of oil to the gas reduces the effective octane of the fuel by a few points. Oil injection or premix really does not matter, as the oil finds it's way into the combustion chamber.

The effect is small in general, so the maximum difference in actual effective octane between oils is likely to be tiny.

Chris

 

[Jaybird]

It could very well be that the bike is not properly jetted, allowing for a lean condition at all curciuts.

The type of pre-mix shouldn't have much effect, but the carburation sure can.

Are you mixing the pre-mix yourself or is it injected? If it is injected, unhook it and start mixing your own. They are not reliable, no way, no how.

If you are mixing yourself, what ratio?

 

[blano]

Look for a air leak. It could also be caused by your air screw on the carb being too lean. Fatten up your air screw setting and or pilot jet. What carb does this bike have on it?

 

[sands]

2. Do new rings have a break in period? / cause pinging?


Yup...When you replace the rings you're usually getting better compression raising the need for a higher octane and good jetting. If you're too lean across the board a higher octane leaded fuel will richen you up quite a bit. a good leaded fuel works excellently in those old air cooled 2 stroke motors...Not only does it lessen pinging you can realize a significant drop in cylinder temps with a high octane leaded fuel and if anything it's worth it for the smell.

Of course there maybe other reasons for the sounds you're hearing as indicated in the suggestions of the other posters...Those old air cooled bikes are loud to begin with so keep that in mind as well.


My buddy was using a mixture of leaded and pump in his Varner modified CR250...He lessened the amount of leaded fuel after a while and it seemed to do well except the bike was starting to lose a tad bit of compression because of the time he had on the motor...His rings were worn so he did a complete top end job...

Well, the compression was back up and the lighter lead fuel mixture he was using before with no problems caused it to ping with the bumped up compression.


The Mobile MX2T wouldn't be the cause for the pinging...

[ July 14, 2005, 03:27 AM: Message edited by: sands ]

 

[badnews]

quote:

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Originally posted by honus402:
1)If you changed rings, your compression ratio should be higher, requiring a higher octane fuel. That is; if you're sure it's pinging.

2) Mobil 1 is a PAO and conducts heat and NOISE much better than a dino oil. My Harleys are quite a bit more noisy with M-1, but run much cooler. Again; are you sure it's pinging?

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How many degrees cooler ???