acroadam Posted March 13, 2011 Report Share Posted March 13, 2011 I'm doing a leak down test and I read it needs to hold 6psi for 10 min...well within 10min, it will drop almost one psi...I can't find the leak anywhere!....should I just forget about it and put it all together, or keep looking for that leak? Quote Link to comment Share on other sites More sharing options...
252wheelieking Posted March 13, 2011 Report Share Posted March 13, 2011 I'm doing a leak down test and I read it needs to hold 6psi for 10 min...well within 10min, it will drop almost one psi...I can't find the leak anywhere!....should I just forget about it and put it all together, or keep looking for that leak? Your motor passed the leak down test, I was told it was suppose to hold 6 psi. for 6 min. & if you lose 1 psi in 6 mins it's acceptable. So its ok to lose 1 psi in 10 min. but anything more than a loss of 1 psi. isn't acceptable. If it was my motor i would go ahead & put it all back together. Quote Link to comment Share on other sites More sharing options...
gotta_goatsfast Posted March 13, 2011 Report Share Posted March 13, 2011 I'm doing a leak down test and I read it needs to hold 6psi for 10 min...well within 10min, it will drop almost one psi...I can't find the leak anywhere!....should I just forget about it and put it all together, or keep looking for that leak? Keep looking. Mine held all 6 psi for well over 20 minutes. I would have accepted 1-2psi drop within that time. Common places are (but not limited to) pto side crank (around key, I use high temp fuel resistant grease to seal it) improperly seated head o-rings (if it has a cool head) a leak at the case seam (and this could mean from the crankcase into the transmission) around reeds/manifold, main seals if the lip was not packed with grease, base gasket, ect.... An other area that is sometimes forgotten is that your leakdown tester leaks (some don't check this). It could be leaking where you plugged the exhaust or around the rubber boot on the tester's valve/gauge or the valve and seams of the tool itself. So get back to your game of "where's waldo" and let us know if you win. EDIT: read you wrong. I thought you said it dropped to one psi. lol, anyway its still good info but 1 psi drop will be acceptable. Quote Link to comment Share on other sites More sharing options...
acroadam Posted March 13, 2011 Author Report Share Posted March 13, 2011 Your motor passed the leak down test, I was told it was suppose to hold 6 psi. for 6 min. & if you lose 1 psi in 6 mins it's acceptable. So its ok to lose 1 psi in 10 min. but anything more than a loss of 1 psi. isn't acceptable. If it was my motor i would go ahead & put it all back together. Alright.ya I had the 10 min to 6 min part mixed up....so ur saying if I leave the tester on the whole night and I lose more than one psi, than I have a leak? Quote Link to comment Share on other sites More sharing options...
252wheelieking Posted March 13, 2011 Report Share Posted March 13, 2011 Alright.ya I had the 10 min to 6 min part mixed up....so ur saying if I leave the tester on the whole night and I lose more than one psi, than I have a leak? yes, you have a leak if you lose any of the 6 psi. but if you don't lose more than 1psi. in 6 min. your motor is acceptable. I wouldn't even do a leak down test over nite. like stated above check your tester. Use some dish detergent & water in a spray bottle & spray the soapy water in all the areas that could leak. If there's a leak you would see bubbles. I really wouldn't worry about a leak if your motor held 6 psi for 6 min. & only loss 1 psi. Your OK put that motor together & come ride with us @ busco beach NC on May 13th-15th..... Quote Link to comment Share on other sites More sharing options...
acroadam Posted March 13, 2011 Author Report Share Posted March 13, 2011 yes, you have a leak if you lose any of the 6 psi. but if you don't lose more than 1psi. in 6 min. your motor is acceptable. I wouldn't even do a leak down test over nite. like stated above check your tester. Use some dish detergent & water in a spray bottle & spray the soapy water in all the areas that could leak. If there's a leak you would see bubbles. I really wouldn't worry about a leak if your motor held 6 psi for 6 min. & only loss 1 psi. Your OK put that motor together & come ride with us @ busco beach NC on May 13th-15th..... Thanks everyone..haha, that's a little far for me..thanks tho...I'll be at little Sarah Oklahoma weekend of may 20th Quote Link to comment Share on other sites More sharing options...
Jereme6655 Posted March 14, 2011 Report Share Posted March 14, 2011 definately use the soapy water to find any leaks. when i assemebled mine i was losing .5-1 psi every 10 minutes and it just had me a little worried. (even though my builder told me that you could run it perfectly fine like this) So i started working with the soapy water.....trust me....when you find the leak you'll know. Mine was another overlooked one.......it wound up being a leak in one of the sparkplug washers.....i hadn't tightened them enough to create a good seal. After i tightened it a little i did another leakdown.....held 6psi for over 3 hours... Quote Link to comment Share on other sites More sharing options...
acroadam Posted March 14, 2011 Author Report Share Posted March 14, 2011 definately use the soapy water to find any leaks. when i assemebled mine i was losing .5-1 psi every 10 minutes and it just had me a little worried. (even though my builder told me that you could run it perfectly fine like this) So i started working with the soapy water.....trust me....when you find the leak you'll know. Mine was another overlooked one.......it wound up being a leak in one of the sparkplug washers.....i hadn't tightened them enough to create a good seal. After i tightened it a little i did another leakdown.....held 6psi for over 3 hours... I used windex..I couldn't find any more leaks to save my life...so i put the motor back together, sync my carbs. Runs awesome. Now when it stops raining, I will do a plug chop..its close, but still a little rich..thanks for the help guys. Adam. Quote Link to comment Share on other sites More sharing options...
frog Posted April 19, 2011 Report Share Posted April 19, 2011 I used windex..I couldn't find any more leaks to save my life...so i put the motor back together, sync my carbs. Runs awesome. Now when it stops raining, I will do a plug chop..its close, but still a little rich..thanks for the help guys. Adam. So I have a leak between my cases.little air bubbles coming out the rear case vent hose.I alreay tried to midly resurface the cases with emery cloth 12x12'' on 5\8 glass and the the surfaces are PERFECT.There was a little inperfection on the right side(pto).tried diferent sealers(rtv,permatex,threebond) still leaking.Leak down test only holds for 4 minutes then leaks out.Is there another way to seal them.I even changed all the fasteners,new torque wrench,new crank.The only reason I opened it up was the install 4mm crank.Please Help! Quote Link to comment Share on other sites More sharing options...
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