Scarlet is Dead!

[crazy steve]

I would think that if all 4 were running at the same leaness then they'd be balanced and the heat wouldn't be an issue..

Nope, lean is lean. While having a poor carb sync (different mixtures in different cylinders) can cause the problem to manifest itself faster, you'll still melt pistons if the mixture is too lean, balanced or not....

[motoman]

Nope, lean is lean. While having a poor carb sync (different mixtures in different cylinders) can cause the problem to manifest itself faster, you'll still melt pistons if the mixture is too lean, balanced or not....

+1........no common intake as in the automotive world.

[XS1100_OEM4ME]

Octane

I know many use low octane rating fuel. It runs hotter and pre-ign is much more likely and can contribute to piston failure JIMHO

[TopCatGr58]

Frankly my dear, I don't give a Dam !

Hey George,

Just quoting a line from a famous movie regarding Rhett's feelings towards Scarlet! Check your PM's, you might like what you see!!!

T.C.

[petejw]

hey george,
were you by chance running your float levels
on the lean side?

the ony time i had any heating problems on the xs was when i was
playing with fuel heights, anything more than half a mm on the lean
side i noticed the engine to run hotter,

also curious because you said this happened on another
of ur bikes.

jat

[ViperRon]

So sorry for your loss. I have a question, did the head have large grey black carbon build up on it? Carbon build up can impact the piston making a small crack and from there it takes no time to cut a hole. I ask this because looking at the pictures it looks like there was quite a gap between the piston and cylinder . This may have been from heavy wear on the rings which will tend to burn quickly when running lean also. After the oil rings burn or cylinders wear you tend to burn oil. If the compression is still good running lean the oil may turn to hardened carbon build up and crack the pistons. If you judge lean or rich on only plug color and the engine is also burning oil it may be hard to judge the carb settings. You would have an oil burner running way too lean on gas before the color would be close. If what I think I saw is about a .020 piston to cylinder gap oversize pistons will definately be needed.

The 150.00 kit for 1196 overbore kit was still on ebay last I looked and might be the cheapest solution but I'd make sure and get the mix rich because the bigger pistons will tend to run hotter (less cylinder wall) and tend to have more stress in the center point of piston.

[TopCatGr58]

Hey Ron,

Good theory, but he did say that he had been swapping heads, so I would think that he would have noticed if he had considerable carbon buildup on the underside of the heads once they were off....for the swap!

I don't know if he's working late, or just like he said....busy and may not have gotten on tonight yet....but he'll have a nice surprise when he reads his PM's!

T.C.

[GLoweVA]

I have been busy. I just got done putting in a new dishwasher so now we don't have to hand wash the dishes like in the old days.

TC, Thanks, I'l send you a PM back shortly.

In both cases of my holed pistons, I had a failure and I limped it home (at least 15-20miles each time)
The first time it was a pick up coil, so I was down to 2 cylinders trying to maintain 55mph. SO, One of them got too hot and melted.

This last Monday, the gasket gave out on #1 while pushing it too hard to trying to pass someone on the interstate. SO I only had 2-3 good cylinders trying to get her home too. thus #2 & #4 got too hot too.

I do agree with all of you and believe that we should have properly sync'd and balanced cylinders to minimize the chance of this happening.
That means starting with even compression numbers, then also proper valve clearances and then carb syncronization.
I might have been a little too eager to get Scarlet on the road and not paid as much attention to all of these like I should.

I do love the way she rides and handles, it's completely different than the G.

I'll keep all of you posted on what direction I take her.

[GLoweVA]

She may be down, but she's not out.

Thanks to TC, I now have an engine to transplant into her.
I haven't had much of a chance to play with her, been too busy trying to keep the G on the road so I have something to ride to work.
TC brought over an '81 engine, so I've got to get my mechanical advance off the SG engine and do some other stuff to get the 81 engine ready.

I'll put the resurrection of her on another thread.