Burning tip off spark plug!!!

[20fan20]

I'm sure I'm not the only one tha has experienced burning the tip off the spark plugs... Can any one tell me what would cause this... Thank you

[dereksehi]

Too high of heat range for you application I would drop one heat range and try that or call the spark plug manufacturer and tell them what you have going on.

[SLM98]

Too much timing, too lean on carb, too hot a plug, not high enough octane fuel, or a vaccum leak can all cause this

[powerslide]

Better get it fixed before it burns the pistons. As SLM noted, Too much timing, Too Lean, Too hot of plug, Not enough octane. Tell us what plug you have with what Compression with what fuel and how much timing.

[20fan20]

Ar3933 plug, 34 deg timing, guessing 13.5/14- 1 compression... Been getting fuel at the track suppose to be 112 fuel...I kno I should stay away from track fuel

[lilsumo]

To lean then probably, I run that plug with the same timing, compression and fuel. Is this a 2 barrel or 4 barrel? Jey sizes? Cubic inch? There are to many unknowns right now. I saw a guy fight this for 5 nights to find out it was cracked intake. One of those cast 2 barrel bowtie ones. He found it when he finally burnt a piston. Like powerslide said, better find it now or you will pay.

[20fan20]

18 deg 406... 4 barrel carb 86/88 jets... I've just started having this problem what's the odds off the track selling 110 fuel and saying it's 112 ... Do you thnk I should try different fuel 1st?

[sj valley dave]

This won't be the problem that is causing the burned off tips, but most 18 degree heads like a little less timing than 34*. Try 32* and see how it feels, IMO

[SLM98]

Dave is right. Have run the same combo mine liked 30*. This a aluminum or iron block?

[20fan20]

It's a iron block... I'll try 32 deg timing I was goin off the assumption 34 would be good but I'm no engine man that's for sure... Never had the engine on the dyno to tune it... What size carb would be good for this combination ?

[dereksehi]

How many rpm are you running and how big of track?

[SLM98]

1.450 to 1.500 venturi

[superstock50]

86/88 sounds a little lean to me...... i ran about that on a "stock" 23* head in a bomber type class, you might wanna talk to your carb guy. i think Lilsumo may be on to something too, look for a bad intake gasket or carb gasket

[sj valley dave]

I agree with SLM98. We have a 1.65 and a 1.375 that we use. The bigger carb is a lot softer on the bottom and most of the tracks we run on are smaller and the 1.375 is very crisp and responsive on the bottom. We use the bigger carb on the 1/2 mile tracks...I think, if I remember, LOL, that on the 1.375 we are at 84/88 or 86/88 as far as jetting...

[powerslide]

It's a iron block... I'll try 32 deg timing I was goin off the assumption 34 would be good but I'm no engine man that's for sure... Never had the engine on the dyno to tune it... What size carb would be good for this combination ?

I think at this point, you admitting you arent a motor man and you having problems i would spend some money on some dyno time and get the tuning worked out. And yes you should buy fuel elsewhere.

[JustAddDirt]

if you are burning off all the electrodes I would increase jet sizes on all corners.
if you are burning off the left side 1357 plugs.
increase the left side of the carb jetting 2-3 on both left side jets in carb, or get a tapered carb spacer.

[20fan20]

It's been on the left side every time... I'll bump up jet size ... Could it be coil,msd,plug wires or something like that?

[50j]

Intake gasket leak?

[Dirtrunner35]

Check the timing at higher rpm to make sure it's not going to 70 or 80 degrees

[Spbulldog]

May sound funny but it's g force related. It's getting lean on left bank because of g force. Fuel wanting to go to right bank. Run the jets on the left bigger or just richen up fuel mix on that bank