Jump to content

plug breaking


400banshee

Recommended Posts

Never running a 485, my opinion might be void but 145 main and 44 pilot jets on that large of a motor sounds incredibly lean. Most 421cc cubs are running 160+ mains and 50+ pilots. What is your elevation? It could be possible that detonation/heat cracked your insulation? Anyway, carry on...

891 feet a.s.l

Link to comment
Share on other sites

I ran my 492 with 35mm carbs for years with 145 mains and a 40 pilot. When I went to 38mm carbs i run 162 main and 45 pilot. Every motors different..I also jetted a couple 421 cubs. There mains were in the 165 range, 45 pilot.

Link to comment
Share on other sites

Never running a 485, my opinion might be void but 145 main and 44 pilot jets on that large of a motor sounds incredibly lean. Most 421cc cubs are running 160+ mains and 50+ pilots. What is your elevation? It could be possible that detonation/heat cracked your insulation? Anyway, carry on...

Usually when the main is to lean the piston melts. I've seen it happen more then once. This was not the case.
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...