BlueSmoke199

I Have a Enticer 400 top end on a Et340 case and it burnt a hole on the pto side piston. The mag side has a dimple. The exact Hrs Idk but it had about 20L of 91 through it. The heads were decked and opened up for the bigger bore. I am running a stock Ovation Carb and enticer stock Exhaust. What's weird is it was running strong and smoking normally. Anything I can check I want to before I reassemble so Please help!
Andy

kccats

The Ovation 2 barrel is a PITA! There is a welch plug on top in the center! I had another prob with it with the choke plunger! You would be better off with the 440 Exciter single carb and open up the stock exhaust!

BlueSmoke199

I have No problem understanding this carb is a pain in the rear! But I thought I had it sorted. I am likely to go back to a single carb manifold port it and put a taper bored flat or round side on. I have enough rise on the bars the cable isn't stock and I don't mind making something work. Also I have a semi complete exhaust I am working on (stinger to a mbrp can)

ALL that aside why'd she burn up after running so strong? Lean, timing or Fuel?

kccats

Lean! The exciter carb is a straight bolt up with the oil pump cable! The stock pipe has a can built into it! And the mod is very straight forword and simple!

BlueSmoke199

I'm thinking it could be the choke cable binding was making it run rich then relaxed. Or my wiring harness has issues bc my light was working intermittently. Don't wanna roast another top end, I still have the 340 top end and carb maybe I will start there. If it's a crank seal it would lean out so then I could be risking $400 in parts and a cold walk home on a snowy day. From what I understand you would slap it back together and just swap the carb?

yamadad4

they always run the best just before they melt. if your crank seals are good, i would question the fuel you used or the fuel requirements that may be needed do to the alterations.

shaved head=increased compression=higher fuel requirements. 91 aint always 91, add some ethanol and you got it too hot. over advanced timing makes it hot as well. lots of variables to consider as to the burn down.

you can usually distinguish detonation between lean burn based on the pistons. since yours holed out, pre-ignition or detonation comes to mind, especially if the other piston was just about to follow.

kccats

You could put it together and then test the seals? Or just replace them while it's down!