1980 Honda 110

[1985BigRed250ES]

I have been restoring a '80 110 ATC. In the process of restoring it, I had to swap the heads out due to the old one being stripped. the head that I purchased had the CDI setup in it. my atc has the points setup. I had that swapped out at an atv shop. while it was there I had the timing chain changed. I got it mostly back together now except for the muffler and seat. The first spark plug was new and it lasted two weeks. I wasnt fouled, just would no longer fire. I purchased another new NGK D8HA plug from oreillys and it has lasted until two weeks ago(last time it ran). It was kinda sooted but not fouled. I did clean the plug and it will not fire. I put in a "test" plug and it ran great. the plug that came out of the ATC was checked with a meter and it shows to have continuity(sp?) through it. It refuses to fire on the plug. it will only run on the test plug which is a plug I borrowed from grandfathers bigred, take into account that I didnt screw the "test" plug all the way in. My question is: What could be causing the ATC to go through spark plugs? any help will be appreciated. I do have a manual.

[1985BigRed250ES]

oh BTW I am also running it without the muffler, can that have an effect on the plugs?

[MudBug]

without the whole exhaust or without the muffler itself?

[Vealmonkey]

I don't know if the muffler would expect the spark plug, but it isn't healthy for your valves. At least find some kind of universal muffler for it and give it a little back pressure. Also a straight through pipe is more than likely hurting your performance, your exhaust needs a measure of backpressure.

[85Tecate]

I ran a straight pipe on a YTM200. Ran the piss out of it but did seize the engine up 3 times. I think it was due to a 40 over bore and lack of oil to the top end. The cam bearings are what seized. Anyways, it ran perfectly fine other than that. Not sure exactly what caused it.

[1985BigRed250ES]

I don't know if the muffler would expect the spark plug, but it isn't healthy for your valves. At least find some kind of universal muffler for it and give it a little back pressure. Also a straight through pipe is more than likely hurting your performance, your exhaust needs a measure of backpressure.

I will try to get the muffler repaired soon so that I can put it back on the ATC. I am running it with just a pipe and no muffler. Could it be firing too hot, causing the plug to burn out? is that even possible?