Jump to content

compression probs ) help)


Recommended Posts

Ok, I live in mid michigan which i think is around 800ft. My compression was 105 in each cylinder. I milled the head .030" and it raised it too 120/123 maybe 125 Guage has 5psi grads. My question is when I baught the shee the guy said it had a recent overbore, but he didnt know how much. My question is does this sound right? Does the stock compression sound correct and does the after mill psi sound correct. I thought a .030 should of raised the psi 25-35 in each cyl. Should I get a new tester? I didnt do any of the tricks yet...E.G oil in the cyl's, or ring clearance. I didnt do the ring trick because i dont know how. But i do know i can move the pistons fore/aft within the jugs. Am i supposed to be able to do this? And if so how much? Thanks. :whoa:

Link to comment
Share on other sites

Well see the problem is your rings are most likely shot. If you were down to 105, its time for a rebuild. Milling the head will raise the compression and make it run better, but its a band-aid, and didn't fix the problem. Tear it down, see if it needs a new bore, and if still fits the pistons well, hone it and get new rings. Then test it and tell us what you get.

Link to comment
Share on other sites

Thanks bro. I only milled the head to enhance psi,of course that was before I knew the psi was low. because im new to the site and just heard of it. I only checked the psi to see a before and after effect. And im glad I did. Now i know it needs a new top end. How do i know if i can just hone it and put new rings on it? Vs. boring and new pistons and new rings? Also It seems weird that the psi was that low because it started easy, and always started on the 1st or 2nd kick. I thought if it was bad psi that it took a lot to start it.Thanks for the response.

Edited by german hospitality
Link to comment
Share on other sites

Where is a good place to send my jugs too? So If i just send them my jugs and tell them to bore / hone them. They can "mike" it out and tell me what pistons and rings to use? Since now im in the dark because the guy said it was bored and obviously he lied. So i have no idea whats in there unless i pull the jugs and mike the pistons. What is the rule of thumb for this. Say the pistons is _____Diam, what should the jugs Diameter be. I just didnt know if this is something i could do my self by sending the jugs to the local machine shop and then specing out the pistons and rings and assembling them. Or is it easier and more cost effective to just have someone supply me with all the info and parts?

Link to comment
Share on other sites

Sucks that an ass bag would tell you that, it was freshly bored.

My buddies just looked at 2 or 3 banshees in the last month before he settled on a 400EX (yeah...I"m stll laughing at that...)

 

Brought a snap on compression gauge to each one they looked at, pricesless insurance.

Two of them were hard to start (never a banshee trademark) and low and behold, less than 100PSI in those two. Go figure. The next guy came along and bought them I'm sure...

 

There are plenty of builders in MI more than capable of measuring your cylinders and telling you what size to buy for the pistons.

 

Grand River Racing on the West Side, B&R Racing in the Saginaw/Flint area, Magic on the East side...and plenty of machine shops along the way...

 

Get out the yellow pages and do the walking...make the calls, and get a comfort level with who your going to take them to.

 

Good luck...sorry about that dickweed you bought it from...

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...