Spark plugs coming out

[sprinklerman]

Trinity Racing logic ftw.

[oldskool]

How many times you kick to get 140? Did you have throttle wide open?

[RadarRacing]

It has higher c9mpression than that with 18cc domes. Since Kevin Herr did the porting how bout you call him and spend $60 or $100 or whatever he charges for his domes nd have him hook you up right. Spitting plugs out doesnt ALWAYS do damage quickly but it can. I dont even check cranking compression because it isnt necessarily correct depending on the motor and gauge. I check squish and CC the volume and check the math.

[stoopidfast]

I kicked until the needle stopped moving with WOT.

[stoopidfast]

I see "squish" mentioned a lot.  What exactly is that and how do I measure it?

[sleeper06]

As stated 18cc domes are race gas domes regardless of static compression with your set , go buy 110 octane put it in , if plugs don't back out u found your issue , do a leakdown domes on the ragged edge will deto from lean condition

[sleeper06]

Stick a peice of solder in the cylinder parralell with the wrist pin , bend solder so it touches the cylinder and domes mating area, kick the bike measure the solder

[oldskool]

you want to see  .040 to .050   .045 being ideal

[Rigid_Banshee]

^^ On any motor setup ? ^^ im still fairly new to measuring squish too so just wondering

Edited May 21, 2015 by Rigid_Banshee

[okbeast]

You mentioned Kevin did the port work, did he set up the domes also? I would check with him on this issue if so. A lot of times port work may show a lower kicking compression number which can be misleading.

[Larry's Shee]

So, where did you get the domes? Who recomended that size? What fuel were you using?

 

Other than backing plugs out, did it make unusual noises? (mostly for my own info)

[CrazyBRONCOguy]

I am having the same issue with a 4 mil dune/play port Herr Jugs motor. Plan on checking the squish this weekend. I fully believe the domes need to be bigger on mine to run pump gas like it was suppose to be for.

 

do you cc the domes with a plug in it or fill in the plug hole with some clay or the like?

 

Have read else were that if you have an adjustable timing plate to check that and make sure it has not moved, I read that as an issue that can cause the detonation which makes the plugs back out.

[stoopidfast]

So, where did you get the domes? Who recomended that size? What fuel were you using?

 

Other than backing plugs out, did it make unusual noises? (mostly for my own info)

I believe I got the domes from Kevin, they may have also come from F.A.S.T.   The dome size I believe was a calculation of what kind of performance I wanted from my machine, based on elevation, port, fuel and timing.  When I put my engine to gether I was getting 140psi, and by reading many other posts that should have let me run pumpo gas, so I was running premium.  Plugs were backing out then and also when I am running a 50/50 between VP108 and premium.  My next run will be 100% VP.  As for the noise, there seemed to be quite abit of ping coming from the exhaust and no matter how I ran it there still seemed to a wet oil residue at the tips of the pipes.

Thanks.

[98_sheester]

That noise might be from early deto i believe i read that around here some where

[trickedcarbine]

I am having the same issue with a 4 mil dune/play port Herr Jugs motor. Plan on checking the squish this weekend. I fully believe the domes need to be bigger on mine to run pump gas like it was suppose to be for.

 

Ya don't say.....?