SHEEMAN0415 Posted April 13, 2015 Report Share Posted April 13, 2015 Hey guys, just picked up a banshee it dont really have any balls til i hit the powerband. I dont have a leak down tester yet so while it was runnin i sprayed carb cleaner around all places i thought there might be a leak and didnt get nuthin. Im getting a tester this weak so ill know for sure. But anyways did a compression test got 95 on the left 120 on the right. Theres i noticeable less exhaust coming out of the left pipe, and alot of oil spits from the right. What you guys think? new rings or just rebuild the whole top end? Quote Link to comment Share on other sites More sharing options...
uman1030 Posted April 13, 2015 Report Share Posted April 13, 2015 Probably ran lean on the side with 95. You'll want to figure out what caused it before tear down. 1 Quote Link to comment Share on other sites More sharing options...
Phelps Posted April 13, 2015 Report Share Posted April 13, 2015 110 is about minimum for any performance. i would consider even 120 to be too low. def time for a rebuild. 1 Quote Link to comment Share on other sites More sharing options...
SHEEMAN0415 Posted April 13, 2015 Author Report Share Posted April 13, 2015 Ok so thats definitely why it has zero balls? LOL and im pretty sure he ran it way lean> the guy before me didnt take very good care of his stuff. That or i think there is an airleak somewhere. I will know this weekend when i get my leak down tester:) Quote Link to comment Share on other sites More sharing options...
SHEEMAN0415 Posted April 13, 2015 Author Report Share Posted April 13, 2015 your left side is toast if its only 95psi, have it bored n honed, piston kit, gaskets blah blah blah, you'll be back in business in a jiffy better do a good carb cleaning too, left side sounds plugged up to me. prolly why its 95psi lol. One other question, do i have to get it bored or can i get away with just getting it honed? thanks! Quote Link to comment Share on other sites More sharing options...
uman1030 Posted April 13, 2015 Report Share Posted April 13, 2015 (edited) Some one capable of measuring the bore would have to tell you that really. it could be slightly oblong/out of round or larger then the other jug. Edited April 13, 2015 by uman1030 1 Quote Link to comment Share on other sites More sharing options...
SHEEMAN0415 Posted April 14, 2015 Author Report Share Posted April 14, 2015 yeah thats what i think too i just cleaned one a couple minutes ago but gotta do the other one tomorrow ran outta time:(. maybe there out of sync. Thanks guys btw i appreciate it!!!! 1 Quote Link to comment Share on other sites More sharing options...
blowit Posted April 14, 2015 Report Share Posted April 14, 2015 I tend to disagree with the "just bore it" sentiment. The main reason so many Banshees are on their last bore. Only bore if it is needed! the only way to know is to have it properly measured by a machine shop. I look for things like a ridge at TDC from the rings, taper, oval, and overall dimensions. We draft a worksheet for bores to determine all this. It might not seem a big deal if you are at a low bore but what if you blow it and need several bore sizes to clean up the bore? Never bore unless required. All the numbers you need are in the manual. Brandon Mull Engineering 2 Quote Link to comment Share on other sites More sharing options...
registered user Posted April 14, 2015 Report Share Posted April 14, 2015 I tend to disagree with the "just bore it" sentiment. The main reason so many Banshees are on their last bore. and crack the intake bridge or boost port 1 Quote Link to comment Share on other sites More sharing options...
SHEEMAN0415 Posted April 15, 2015 Author Report Share Posted April 15, 2015 Im gonna pull the jugs off next week and im picking up a whole top end kit and engine honer this weekend gonna do it right! Hopefully the cylinders dont need to be bored. Old lady would want me spending that much on it lol, giess ill just have to kick her to the curb Quote Link to comment Share on other sites More sharing options...
blowit Posted April 15, 2015 Report Share Posted April 15, 2015 I would recommend if you are buying anything, first buy a 2-6" telescopic bore gauge, and a mic set. Even the China ones will do just fine for this. Then you can be sure what you have. Anything less will be guessing. You can probably own all this for $150 bucks and have the ability to check any other bores in the future. I have personally bored a few engines with nothing more than a 3 stone hone in a pinch, but I don't recommend that unless you know the tricks. You can screw this up pretty quick. Final finish should be done with a 240-280 grill ball hone which will help smooth the port openings, BUT you still need to do a proper port chamfer. 1 Quote Link to comment Share on other sites More sharing options...
SHEEMAN0415 Posted April 15, 2015 Author Report Share Posted April 15, 2015 I would recommend if you are buying anything, first buy a 2-6" telescopic bore gauge, and a mic set. Even the China ones will do just fine for this. Then you can be sure what you have. Anything less will be guessing. You can probably own all this for $150 bucks and have the ability to check any other bores in the future. I have personally bored a few engines with nothing more than a 3 stone hone in a pinch, but I don't recommend that unless you know the tricks. You can screw this up pretty quick. Final finish should be done with a 240-280 grill ball hone which will help smooth the port openings, BUT you still need to do a proper port chamfer. Ill invest in a bore gauge i already got a set of mics cause im big into reloading so. Thanks for the info! Quote Link to comment Share on other sites More sharing options...
blowit Posted April 15, 2015 Report Share Posted April 15, 2015 I would just add that the crosshatching in cylinders is actually VERY important as it aids in oil retention. We rarely tear an engine down and not at least hone it to renew crosshatching. If you are new to this, do some reading on it and tune your hone speed and cycles to get the correct angle of crosshatch. I have seen a LOT of guys (even at the dealership) just grab the drill and spin her up to max and hone like a wild man. You will actually run these pretty low speed. 2 Quote Link to comment Share on other sites More sharing options...
SHEEMAN0415 Posted April 16, 2015 Author Report Share Posted April 16, 2015 I would just add that the crosshatching in cylinders is actually VERY important as it aids in oil retention. We rarely tear an engine down and not at least hone it to renew crosshatching. If you are new to this, do some reading on it and tune your hone speed and cycles to get the correct angle of crosshatch. I have seen a LOT of guys (even at the dealership) just grab the drill and spin her up to max and hone like a wild man. You will actually run these pretty low speed. Run the hone at a slow speed? What kinda crosshatch would you prefer? Quote Link to comment Share on other sites More sharing options...
registered user Posted April 16, 2015 Report Share Posted April 16, 2015 chinese bore gauges will likely get the job done but have a look through ebay first. many times you can find great deals on used mitutoyo stuff. sure it may have been dropped a time or two but its probly still as accurate as the chinese stuff . chinese stuff should be your last resort if all else fails and your broke Quote Link to comment Share on other sites More sharing options...
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