Williamallisonx Posted June 28, 2014 Report Share Posted June 28, 2014 First post on this so apologies in advance for any mistakes.. Problem banshee was pressurising cooling system (blew pipe one day) and air bubbles in radiator so I assumed head gasket? Striped of head had it skimmed and repaced both top and lower gaskets and retorqued 22fp.. Tried to fire bike up wouldn't start finally got it started by putting bit fuel through air intake but no bike revs nearly full throttle as soon as I fire it up which I'm assuming is an air leak? I did a compression test and both cylinders coming up 70psi which I know is low but when I put my hand over reeds when doing comp test I can feel air coming out through them is this normal? Why would I have such low compression after replacing gaskets maybe rings? Any help would be appreciated thanks.. Quote Link to comment Share on other sites More sharing options...
Surfrjag Posted June 28, 2014 Report Share Posted June 28, 2014 are you holding the throttle open while your kicking until the guage stops moving? did you put the choke tube between the carbs? if you don't it can rev up Quote Link to comment Share on other sites More sharing options...
Williamallisonx Posted June 28, 2014 Author Report Share Posted June 28, 2014 (edited) I did the compression test with the carbs off altogether but beforehand when they were on yeah choke tube was on tight.. Edited June 28, 2014 by Williamallisonx Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted June 28, 2014 Report Share Posted June 28, 2014 Think of any of the stupid stuff not in the manual. Seen many times where someone is in the top end so they move all the cables and wires and something gets moved or bumped so it's loose or not connected. The throttle cable has all the ends in the bungs of the 2/1 section, the ends is seated in the carb tops and throttle perch? Quote Link to comment Share on other sites More sharing options...
Williamallisonx Posted June 29, 2014 Author Report Share Posted June 29, 2014 Cheers for the reply but that wouldn't explain the low compression I'm getting and the air coming back out through the reeds I'm thinking maybe bad rings? Quote Link to comment Share on other sites More sharing options...
Larry's Shee Posted June 29, 2014 Report Share Posted June 29, 2014 Worn/broken reeds would allow air back out. Rings have absolutely nothing to do with it. Try a different comp gage. Was this previously running? Quote Link to comment Share on other sites More sharing options...
Williamallisonx Posted June 29, 2014 Author Report Share Posted June 29, 2014 (edited) Yeah ok must check reeds then as can feel air coming back out through them.. Yeah bike was running 100% started first kick was just using Coolant and pressurising cooling system hence why I did the gaskets.. As for comp gauge it's brand new and reads ok on my car.. Edited June 29, 2014 by Williamallisonx Quote Link to comment Share on other sites More sharing options...
tfaith08 Posted July 1, 2014 Report Share Posted July 1, 2014 (edited) For 4 posts, you seem to have done your research. Assuming that you just got it, check these: Airleak. Make sure your leak-down tester doesn't have an airleak. That'll have you running in circles for days. Jetting (rare without throttle opening) Throttle position on both sides - also check to see if the PO put the wrong slide(s) in because I've seen it happen. Carb caps, rubber gasket, Carb boots and carb fitment Leak at crossover tube Check the carb for cracks or chips; I've also seen that happen. It's very unlikely, but it's a possibility nonetheless. The low compression side of things is likely unrelated to the sporadic revving, but it isn't impossible. Take your pipes off and look through the exhaust ports at the back of the cylinder. It helps to tilt the quad on the back end while doing this. Take a flashlight and look through the spark plug holes to check the sleeve around the exhaust port. You won't be able to see everything, but you can see a good bit of your cylinder. Do the same thing looking through your with your reed cages off. Rotate the crank until the pistons rings are in sight from the exhaust port. If you had coolant troubles, you likely overheated the cylinder and fried the rings (and potentially the cylinder). Low compression is due to bad rings, piston damage, sleeve damage or cracks, head damage or warping or cracks, head gasket sealing issues, a bad compression gauge, previously cross threaded spark plug threads, or a lack of available airflow. If those don't get you an answer, get back to us. EDIT: Only a few of these will be related to problems experienced on both cylinders. Edited July 1, 2014 by tfaith08 Quote Link to comment Share on other sites More sharing options...
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