Burned up the #2 piston....again (Revisted)

[emdsapmgr]

Re: Burned up the #2 piston....again

Re: Burned up the #2 piston....again

A missing water deflector can take out just one cylinder. Did you measure the head temps with a laser gun while idling? How do you have the telltale hooked up-the original telltale hose going through the original lower cowl restrictor nipple? Any chance that #2 shows any sign of water in the cylinder?

 

[Reggie08]

Re: Burned up the #2 piston....again

Re: Burned up the #2 piston....again

you by passed the vro system. and used 25:1 premix. did you cap of the oil inlet airtight?

when you unplugged the Vro did you check your overheat alarm was still active?

did you replace the waterflow deflectors in the block?
they swell up and do cause waterflow restrictions.

just a thought

The VRO was already disconnected when I picked up the motor. I didn't do anything different to it other than replacing some of the fuel lines. I know the inlet nipple at the lower cowling is plugged off. Outside of that, everything else is still hooked up as far as I can tell.

A missing water deflector can take out just one cylinder. Did you measure the head temps with a laser gun while idling? How do you have the telltale hooked up-the original telltale hose going through the original lower cowl restrictor nipple? Any chance that #2 shows any sign of water in the cylinder?

The water deflectors (I'm assuming you're talking about the small tubes inside the cylinder head) are installed. But I didn't measure the head temps. And unfortunately, the sensor was in-op and was something I was getting ready to replace. The sensor on the #1 and 3 cylinders worked properly (set off the horn when grounded) but the other one didn't work The telltale is hooked up the same as it was before. The only change to that is I replaced the nipple on the lower cowling. The #2 cylinder didn't show any sign of water in the cylinder. After each trip I would pull the plugs and check them. Friday night I noticed the #2 and 4 plugs were black which told me there wasn't any water intrusion but that it may have been running rich.

 

[Reggie08]

Re: Burned up the #2 piston....again

Re: Burned up the #2 piston....again

What did you set the timing at? What spark plugs are you using?

Dhadley,
The plugs are Champion QL77JC4's gapped at .030. I was able to put the motor in the water and verified the WOT was set at 28 degrees. Unfortunately I marked my flywheel improperly so I couldn't verify WOT timing on each cylinder and it was getting late in the evening. I'm going to re-mark my flywheel hopefully this evening and re-check the timing on each cylinder. I say "hopefully" cuz my wife came home from work not feeling well so we ended up not running errands. However, we'll probably run those errands tonight.

But here's the method I figured I would use to determine TDC for each cylinder. I'm going to count the number of "teeth" on the flywheel and divide that number by 4. Then starting from the "24" mark on my flywheel, count the number of teeth and mark the flywheel. And since the #1 should fire first, I'm going to assume, each mark will be in succession (#2 then #3 then #4). Is this a correct method or is there a better/correct method?

 

[Dhadley]

Re: Burned up the #2 piston....again

Re: Burned up the #2 piston....again

I use what they call a motorcycle timing gauge. It's nothing more than a dial indicator that screws into a spark plug hole. You can do the same thing by using the method in the book that describes how you found TDC to set the pointer. This time instead of moving the pointer you'll be making a line with a number above it.

 

[Reggie08]

Re: Burned up the #2 piston....again

Re: Burned up the #2 piston....again

Yeah the method I used last night didn't include my piston stop tool nor did I figure in the 28* degree difference for WOT timing on each cylinder :redface: So I have to remove my marks on the flywheel and re-accomplish it.

 

[Reggie08]

Re: Burned up the #2 piston....again (Revisted)

Update.

I thought I'd try determining WOT timing for each cylinder using J. Reeves' static method. This is what I came up with. I marked each TDC for each cylinder then advanced that mark 28 degrees and marked it as my WOT timing mark for that cylinder. I'm sure the mark weren't definitely correct, but I was looking for consistency meaning for example, if all my marks were off by 1/2" to the left of my timing pointer, it would at least tell me if the cylinders were firing properly. Make sense?

Here's what I found:

When I check the #2 cylinder, I see my marks for #2 and #4 I verified it by adding a small mark to the left of the #2 mark and a small mark to the right of the #4 mark. Both marks showed up in my timing light. When I check WOT timing for the #4 cylinder, I see only the #4 mark. The #2 mark is on the opposite side of the flywheel as it should be.

Additionally, when I checked my WOT timing for #1, I see my #3 mark about an 1 1/2 inches clockwise from my #1 mark. When I check #3 mark, I see only my #3 mark with the #1 mark being on the opposite side of the flywheel. Again, as it should be.

I know this probably isn't the best way to check all four, but I thought this might be a good starting point. Based on what little I know, I'm guessing my powerpacks may be fine but my timer base could be shot?

Any suggestions on what I need to check?

 

[Reggie08]

Re: Burned up the #2 piston....again (Revisted)

bump

 

[Reggie08]

Re: Burned up the #2 piston....again

Re: Burned up the #2 piston....again

Dhadley,
Tried to send you a PM but it said your mailbox was full. I'm hoping you can give me some insight to this

 

[Dhadley]

Re: Burned up the #2 piston....again

Re: Burned up the #2 piston....again

You're on the right track. When you run it in the water make sure the pick up on the timing light is as far away from other wires as possible. Keep us informed as to what you find.

 

[Reggie08]

Re: Burned up the #2 piston....again

Re: Burned up the #2 piston....again

Thanks Dhadley. I'm going to try to get it in the water this week/weekend to verify what I found.