bunboy1 Posted April 29, 2008 Report Share Posted April 29, 2008 hi all i was wondering if anyone knows how to do a leak down test? when i did a compression test, i left the gauge on overnight and the pressure stayed at 145 psi. is that how you do it? thanks Quote Link to comment Share on other sites More sharing options...
KaosBanshee44 Posted April 29, 2008 Report Share Posted April 29, 2008 Do some searches at the top right and you'll get alot of info and people that ask questions about leakdown testing. Here is a thread that may help ya out! http://www.bansheehq.com/forums/index.php?...5&hl=rnbrad Quote Link to comment Share on other sites More sharing options...
dajogejr Posted April 29, 2008 Report Share Posted April 29, 2008 hi all i was wondering if anyone knows how to do a leak down test? when i did a compression test, i left the gauge on overnight and the pressure stayed at 145 psi. is that how you do it? thanks No....a compression tester has a blow back valve in it. So...in other words, it should not decrease pressure until you hit the relief button. Bascially, you plug both exhaust ports, one intake port...and pump 6 PSI into the motor (yes...ONLY 6 PSI). The gauge you use has to have any check ball or blow back valve in it removed.... Test it for 5 to 10 minutes. No loss in pressure is optimal, but less than 1 PSI a minute is acceptable. Quote Link to comment Share on other sites More sharing options...
98'banshee Posted April 29, 2008 Report Share Posted April 29, 2008 Buy a leakdown tester. they are universal to 2 strokes and 4 strokes. a leakdown test is seeing how much pressure your piston rings hold before there is to much pressure and blowby. Quote Link to comment Share on other sites More sharing options...
dajogejr Posted April 29, 2008 Report Share Posted April 29, 2008 Buy a leakdown tester. they are universal to 2 strokes and 4 strokes. a leakdown test is seeing how much pressure your piston rings hold before there is to much pressure and blowby. Ahh...no. If you can get a cylinder to hold 120 to 125 PSI (stock) the rings will hold 6 PSI. The leak down tester is designed to test the other parts, like base gaskets, orings, crank seals, intake seals... I would have to say the most common areas for air leaks are intake gaskets and crank seals... Quote Link to comment Share on other sites More sharing options...
bunboy1 Posted April 29, 2008 Author Report Share Posted April 29, 2008 hi all, i really don t feel like taking my pipes off again. do you think that i can get away with using the carb cleaner spray around the intake gaskets. if the crank seals are leaking, will engine oil leak into the crankshaft compartment? how much does the leak down tester cost>? thanks Quote Link to comment Share on other sites More sharing options...
Bansh-eman Posted April 30, 2008 Report Share Posted April 30, 2008 dont rely on that to tell u if there is a leak. you can gather parts and build on or go here and buy this if u have a compresser Quote Link to comment Share on other sites More sharing options...
dajogejr Posted April 30, 2008 Report Share Posted April 30, 2008 To be blunt... it's less than 60 bucks for a pre made tester, or you can build your own. You can use carb cleaner to test the ignition side crank seal, base gaskets and the intakes. If removing the exhaust is too much work for you, you might want to get a 4 stroke.... Quote Link to comment Share on other sites More sharing options...
bunboy1 Posted April 30, 2008 Author Report Share Posted April 30, 2008 my banshee is running fine. should i still try to do the leak down test? i have been reading a lot of forums and most say that it is a pain in the ass to do. what do you guys think? thanks Quote Link to comment Share on other sites More sharing options...
dajogejr Posted April 30, 2008 Report Share Posted April 30, 2008 Well...again, if you're not willing to take the exhaust off...then yes, it's a Pain in the ass. Really, once the carbs and exhaust are removed, it's less than 10 minutes worth of work. If the bike is running fine, plugs look good, no missing, back firing, RPM raising for no reason...don't worry about it. Careful builders will compression test AND leak down test a motor before ever firing it up....it's a piece of mind AND point of reference. Quote Link to comment Share on other sites More sharing options...
bunboy1 Posted May 14, 2008 Author Report Share Posted May 14, 2008 hi all, i am trying to do a leak down test. i got the carbs and pipes off, and it seems i have an air leak somewhere. i am losing 1 psi every 30 seconds or so. i am spraying dish soap with water every where, but i still can t find the leak. where is the most common places or what other bubbly solution should i use? thanks Quote Link to comment Share on other sites More sharing options...
Bansh-eman Posted May 14, 2008 Report Share Posted May 14, 2008 one of your crank seals probly Quote Link to comment Share on other sites More sharing options...
bunboy1 Posted May 14, 2008 Author Report Share Posted May 14, 2008 i got some tapered rubber plugs from home depot and i am having a lot of trouble keeping the right one in the intake port. do you guys have any ideas on keeping the damn thing from popping out? does the left side of the crankcase, where the flywheel is, airtight? if i leave the dipstick in the clutch cover snug, i should not get any pressure drop if it is the right crank seal? thanks Quote Link to comment Share on other sites More sharing options...
Bansh-eman Posted May 15, 2008 Report Share Posted May 15, 2008 you can try using PVC end caps rather then rubber plugs. when you squeez soft material against another soft material they dont normally hold well, but the pvc is just like clamping your carbs in there. for the crank seal it should not leak. you DONT have to have your clutch cover on to do a leakdown test. infact you shouldnt have it on so you can see if the seals are leaking Quote Link to comment Share on other sites More sharing options...
bunboy1 Posted May 16, 2008 Author Report Share Posted May 16, 2008 hi all, i went and got some pvc tubes and now the nothing pops out, great!!! now when i do my leak down test, i do have a pressure drop and from 6psi it take 1 min and 19 sec to get to 5psi. do you guys think that is ok? or should be worried? thanks Quote Link to comment Share on other sites More sharing options...
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