Satsol67 Posted November 21, 2006 Report Posted November 21, 2006 Ok now I am stumped. I just redid the topend again but this time I took the cylinders to the shop to have the pistons fitted. I thought it needed just a little bore but when i picked them up he told me all it needed was a hone. When I got home I checked the ring gap to be sure and they are the exact same and they all are .010. After I got it together I did the compression test and the left side is 145 and the right is 115. It seems to be running good but I know thats not right. What should I check? I am reusing the O rings for the cool head. Would that be it? There is no cross over tube. I dont think that would be the problem. The domes do have some piston damage from the last time the piston came apart. Would that be it? Can it be the reeds going bad? Please give me some suggestions Ron Quote
bansheefreak Posted November 21, 2006 Report Posted November 21, 2006 i am curious if the damaged dome is the side thats low??? if so i would get need head or dome... Quote
Satsol67 Posted November 21, 2006 Author Report Posted November 21, 2006 I was wondering the samething. I didnt pay attention when I put them back in. I would like to go down a size or 2 but if the compression is going to be 145 with 22cc then I will just stay with them. I dont have the cash for new domes right now. Will it do anything if I run it like this for a while? Quote
Bansh-eman Posted November 21, 2006 Report Posted November 21, 2006 i would NOT run it with the sides being mor then 10% differance... and in your case its much mor then that... now thats taking that your tested is right... how many times did you check it ? also did you make sure your threads are clean and dont have metal or debris on them? the dome having marks wont make your cyliders be that far off... 1 to 2 lbs MAX and thats being generous.... if your head was leaking the needle should drop on your tester... if its not dropping your holding the pressure... Quote
Satsol67 Posted November 21, 2006 Author Report Posted November 21, 2006 Hrmm. I dont think my compression test is set up like that. I dont think it will let air back out. It has a pin at the bottom where it goes in the head like a valve stem. I wonder if it would mess it up if i drilled it out then I would be able to tell if its leaking. If in fact it is leaking would it be from the O ring around the dome? Quote
Bansh-eman Posted November 21, 2006 Report Posted November 21, 2006 there or the threads on the dome... i wouldnt waste a compression tester to see if its leaking... pressurize your top end and shoot some water with soap around all your gaskets and shit and see if anything bubbles.. Quote
Satsol67 Posted November 21, 2006 Author Report Posted November 21, 2006 ok good suggestion. I will try that tomorrow. Quote
Satsol67 Posted November 21, 2006 Author Report Posted November 21, 2006 there or the threads on the dome... i wouldnt waste a compression tester to see if its leaking... pressurize your top end and shoot some water with soap around all your gaskets and shit and see if anything bubbles.. I thought about this all night and was wondering how I would pressurize the topend. I would somehow need to plug up the intake and exaust ports then kick it over. Would it work if I just ran it and did the soapy water trick? Quote
Satsol67 Posted November 21, 2006 Author Report Posted November 21, 2006 I was thinking about taking the head back off and putting just a tiny bit of sealer around the O ring that goes around the domes. What do you think? Quote
Bansh-eman Posted November 21, 2006 Report Posted November 21, 2006 running it will tell you if your blowing air but if you have a leak on your jugs when running your going to suck air not blow air.... if you run it get some carb cleaner and spary on the gaskets and the motor will cutout its just a little harder to tell then bubbles... Quote
dajogejr Posted November 21, 2006 Report Posted November 21, 2006 Go to a new machine shop... At this point, get a new base gasket, NEW orings for the head, and have your cylinders measured...again, by a different machine shop. I posted the piston to wall clearance in another thread....both MM and English. I think the ring end gap is supposed to be .012 to .018, but not 100% certain. I'm certain being at .010 is not causing your uneven compression.... Did you seat the rings on the piston ring lands properly when reassembling this? Did you buy oversized pistons or standard pistons? I think your piston to wall clearance is out of whack... The wrecked dome isn't helping you any, and I personally would replace it...but, it's not causing your uneven compression either... Quote
Bansh-eman Posted November 21, 2006 Report Posted November 21, 2006 I posted the piston to wall clearance in another thread....both MM and English. HAHA i think you mean both metric and standard .... heheheh i know with wiesco prolites on a stock boe you need .010-.012 gap... id always go with the higher number to be safe and not have a ring weld together once it heats up and expands... if you read the papers with your pistons it will tell you how to determine how much gap you need per mm of bore... Quote
dajogejr Posted November 21, 2006 Report Posted November 21, 2006 HAHA i think you mean both metric and standard .... heheheh i know with wiesco prolites on a stock boe you need .010-.012 gap... id always go with the higher number to be safe and not have a ring weld together once it heats up and expands... if you read the papers with your pistons it will tell you how to determine how much gap you need per mm of bore... Doh...yep, MM and American is what I meant...you smart guy you... LOL :beer: Quote
Satsol67 Posted November 22, 2006 Author Report Posted November 22, 2006 I'm going to recheck the compression tomorrow and if still not right i'm going to pull off the right side and see whats going on. It just runs so damn good! Quote
dirt-riceburner Posted November 22, 2006 Report Posted November 22, 2006 Hey, if you do want some domes for cheaper than retail, I have a pair of Noss 21's. It will fit the Pro Desine. It's been used for about 2 months and it's in great shape. $40 +ship. If you or anyone needs it, PM me. Quote
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