Accurate Leakdown Test Procedure 03 Cr250r??

ALB

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#1
Hey guys

I have an 03 Cr250 that was built completely New this past winter(New Crank,Bearings,Seals,Topend,etc..) When I say Bearings and Seals I mean every Bearing and Seal in the entire motor,Tranny and all.Anyway I live at 6700ft with Adv.Temp in summer appx.75 Deg. When summer first began I took the bike out a couple of times and it ran a bit rich but ran very well,after that due to Medical problems(Heart Failure)The bike has sat in the entry way of my house(better part of 3 months) I went to fire it up and it started up on the 2nd kick like it always does,However it runs EXTREAMLY rich down low,won't idle etc... If I take it out and run it hard it seems to clean out and pulls great,but when I let it idle down it won't idle and seems very rich all over again.I checked the RC Valve and it fully opens and closes like it should,I suspect that the Carburetor got a passage or Jet clogged so I have torn it down and cleaned every Orfice and Jet in it and made sure that the Floats are set correctly.However before I put it back together I would like to make ABSOLUTELY sure that the Crank Seals didn't get a nick or flat spot on them during assembely causing a leak,So I researched in other threads and found the $17 Leakdown Tester,does anyone have an accurate Leakdown Test Procedure for the CR250.Thanks
 
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#2
Exact numbers aren't really necessary and vary so much that they are hardly useful. Most of us just go by kickstarter feel.
 

ALB

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#3
Thanks much for your input 76GMC1500,I can appreciate your view.Old school ways(feel) can definitely be a value,I really just wanted to know what the actual leakdown test procedure is for personal info.Thanks
 

D36-108A

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#4
The kickstarter won't show an air leak, only a leak-down test kit will.

Leave the spark plug in, plug the carb boot intake with the kit's nippled plug, plug the cylinder exhaust, hand pump to 6 psi, and start your stopwatch. Watch the gauge and the clock and see how much pressure it loses (leaks) over time.
 

ALB

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#5
Thanks very much D36-108A,I appreciate your help big time.I kinda guessed prior to your post and did like you said,the only difference was that I went at 5psi ( didn't want to take a chance of putting to much pressure in and cause a problem due to my lack of knowledge) Anyway I set it at 5psi and let it set for 15min,there was no loss at all.I will do the test again at 6psi and see what happens,Is the 15min long enough or do you have to let it hold for a longer amount of time? Also if the test holds at 6psi,is there any reason to go to a higher psi or is that considered good? I am so frustrated with this thing,this is one of a very few times in the past 35yrs that I have not been able to get one of my bikes to run clean.I have completely rebuilt the carb,floats dead on( checked multiple times) dropped the stock needle to the leanest position,dropped 2 sizes in the pilot ( 25 ) cleaned and blown out every passage and orfice and the thing still wants to run rich at idle.I live at 6700ft so jetting can be difficult,I talked with JD Jetting yesterday and they insist that there Jet Kit will solve the problem because there kit has both needles and New Needle Jet ( saying the stock needle jet is to rich ) So I went ahead and ordered it,I really HOPE it works.Thanks again for sharing your knowledge.