Jump to content

spark plugs coming loose


Alex29573

Recommended Posts

Plugs backing out are caused by detonation due to too low octane fuel for your compression.

Vibration will not do it unless they are only finger tight and lean jetting will cause pre-ignition which will melt holes in the piston.

 

Dont run it like that. It will be expensive.

 

You bjust beat me with your answer, but 7 deg timing could also be a cause

Edited by Rodneya
Link to comment
Share on other sites

Sounds like to me that 7 degrees timing might be a little too much timing...I would back it down to at least 5 degrees timing. Sounds like it is pre detonating at 7 degrees. We have had plugs starting to loosen up at 5 degrees with 110 octane race fuel. We usually run Sunoco or Turbo Blue.

Link to comment
Share on other sites

Sounds like to me that 7 degrees timing might be a little too much timing...I would back it down to at least 5 degrees timing. Sounds like it is pre detonating at 7 degrees. We have had plugs starting to loosen up at 5 degrees with 110 octane race fuel. We usually run Sunoco or Turbo Blue.

 

 

x2 cant hurt to back it down and try it.

Link to comment
Share on other sites

You've got some detonation issues going on. If your plugs are backing out, don't just keep tightening them up and keep riding. Fix the problem. I'd try by backing your timing down a little bit and see if it helps. If not, then you have 2 options... bigger domes, to drop your compression to where the detonation stops, or change fuels. If it were me, I'd just swap to methanol and keep the domes and timing you have now. It takes a hell of a lot to detonate meth, and your engine will run cooler.

Link to comment
Share on other sites

Can someone tell me if when sparkplugs get loose - if its a problem with not enough octane or is it a problem with too lean of a jet?

 

thanks

I had the same problem on mine a while back.I had no detonation and the jetting was right on.My plugs just seem to loosen slightly after a hard ride.I bought a plug lock for mine on ebay and solved the problem.

Link to comment
Share on other sites

I had the same problem on mine a while back.I had no detonation and the jetting was right on.My plugs just seem to loosen slightly after a hard ride.I bought a plug lock for mine on ebay and solved the problem.

 

Running a plug lock is asking to demo your motor.

Link to comment
Share on other sites

the plugs look good but then again i havent kept riding it. i let it happen twice and i stopped riding.

 

im at a plus 7 timing b/c jim from passion told me to do that. its a 421 setup. he told me to do 110 octane but i think the problem is that sunocco 110 is not really the same as vp. im going to talk to him today.

 

thanks guys

Link to comment
Share on other sites

 

im at a plus 7 timing b/c jim from passion told me to do that....im going to talk to him today.

 

thanks guys

 

not that the folks here don't know what they're talking about, but getting in touch with your builder would be the best first step.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...