Thread: stock 800 compression
01-31-2010, 09:38 AM #1
stock 800 compression
did a compression test on my gsx today and the rear pot was about 142 and the front about 152 cold, what would you guy's think i should do? full topend rebuild,just rings?? im also thinking about skimming the head aswell for abit of performance
any help wouls be great
01-31-2010, 09:48 AM #2
ouch. this would be a decision on your part. some people say 5% others 10%. at 10% your still okay.
you need to find out why its droping. probably beacause of it seized at some point. you should take the head off and look for any signs of alumimium on the cylinder walls. if so you might be able to get away with a hone provided that there are no deep scars. snap a pic and post it once you get the head off. i am assuming that you have already change the fuel lines right?
01-31-2010, 10:04 AM #3
Cheers for the reply, the fuel lines dont degrade like in the US,something to do with the fuel we use,rebuilt the carbs last year,hardly any crud in there! im up for doing the topend,but in acouple of weeks i will take the head off and have look,respraying a mate superjet,so should'nt be on here really
01-31-2010, 04:01 PM #4
- Join Date
- Feb 2006
- Warner Robins, GA Home of the 2007 All-Star Little League World Champions!
Pull the head John and inspect the cylinder for excessive scoring and or aluminum smeared on the sides.
Are you running a pipe? Sorry I can't remember.
01-31-2010, 04:15 PM #5
no pipe just R&D f/a rejetted to your specs and R&D nozzles.if i get a chance this week i'll take the photo of the head and bore ok
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)
By NoMo-xp4me in forum 4-Tec PerformanceReplies: 14Last Post: 01-17-2008, 12:06 PM
By qbzonk in forum Yamaha How To & FAQsReplies: 4Last Post: 08-05-2007, 10:24 AM
By izz0 in forum Yamaha PWC Performance (2-stroke)Replies: 2Last Post: 07-23-2007, 05:23 PM
By dhoad in forum Yamaha PWC Performance (2-stroke)Replies: 1Last Post: 12-15-2006, 01:33 PM
By Super in forum Yamaha PWC Performance (2-stroke)Replies: 14Last Post: 07-14-2006, 12:47 PM