Need some help... Trying to do the leak down test. Motor will not hold air. Leaking on the clutch side. Near the rear, there is a gear, behind the clutch, with a little window to the gears in the trans... That is where the air is coming out. Is this normal? Do I have to split the cases? If so, anyone made a case splitter yet? Need lots of help and info.
HELP!!! Air leak on clutch side. Cases?
- Thread starter Jwhite11
- Start date
You could have a leaky crank seal, thats how the air gets into the gearbox.
There is no need to split the cases to replace it, just remove the stuff in the way, pluck out the seal and replace with a new one.
Do both sides while you are at it.
There is no need to split the cases to replace it, just remove the stuff in the way, pluck out the seal and replace with a new one.
Do both sides while you are at it.
Welcome to BF !! I:I I:I I:I
Now is also a good time to tell you to either get a Clymers repair manual or find the link to the download manual. Don't know if it's because of your parts description, but to me it doesn't sound like the crank seal. Pull clutch cover and spray soapy water around crank seal while pressurizing cylinder. What was the situation that prompted you to do a leakdown?
Now is also a good time to tell you to either get a Clymers repair manual or find the link to the download manual. Don't know if it's because of your parts description, but to me it doesn't sound like the crank seal. Pull clutch cover and spray soapy water around crank seal while pressurizing cylinder. What was the situation that prompted you to do a leakdown?
Blaner
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welcome, I made up a rudimentary case splitter which worked perfectly...
http://www.blasterforum.com/do-yourself-20/diy-crank-puller-43994/ but like its been said, no need to split cases anyway!
http://www.blasterforum.com/do-yourself-20/diy-crank-puller-43994/ but like its been said, no need to split cases anyway!
Thanks all. The motor didn't have any bottom end power, I mean it would hardly run. It had low compression so I did a top end job. Went to do the leak test after top end rebuild and ai was leaking out of the crank case vent. Alot of air, it wouldn't hold any pressure. So I take side covers off.
Replaced left side seal, Put air to it while checking right side seal, with clutch and everything removed. Noticed air coming from the rear of the clutch area from the trans.
Would the right side crank seal stop air from getting into the trans?
Thanks for all the info!!!
I am getting frustrated.
Replaced left side seal, Put air to it while checking right side seal, with clutch and everything removed. Noticed air coming from the rear of the clutch area from the trans.
Would the right side crank seal stop air from getting into the trans?
Thanks for all the info!!!
I am getting frustrated.
Hats off for doing a leakdown test before starting it back up. You'd be surprised the number of people who show up here after "doing a top end" and it locked right back up afterwards and they can't seem to understand why.
You are already light years ahead by having the knowledge of what a leakdown test is!
If you have the clutch and primary drive gear off the end of the crankshaft and that seal is not where the air is coming from, chances are you have a broken case/case halves. It's a problem that occurs when people don't freshen up the top end soon enough and run it until the piston is slapping around inside the cylinder. The slap stresses out the intake side of the piston until a piece breaks off and that piece gets lodged between the crank and the case. Usually results in a hole between the crankcase and balancer shaft area. Don't despair however, all hope is not lost.
Cases can be repaired back to 100% in most cases (no pun intended) and have your engine back up and ready to run again.
In order to truly asses the damage however, you'll probably have to split the cases.
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Thanks so much for the info. I have made my mistakes before with the two strokes, so I have learned a leak down is a must. Made a leak down from home depot parts for 28.00 including the plugs. Good tip, buy the rubber feet for tables or crutches. They work well! And thick enough to drill and screw a fitting into..
I guess I better plan on making or buying a case splitter. How are people repairing the cases? Welding or brazing them? Seems like a more delicate task then I could do, especially if it is on a sealing surface... I have another bottom end I bought for parts, maybe I will try the new top end on it?
I guess I better plan on making or buying a case splitter. How are people repairing the cases? Welding or brazing them? Seems like a more delicate task then I could do, especially if it is on a sealing surface... I have another bottom end I bought for parts, maybe I will try the new top end on it?
I generally quote people $50 per case half plus return shipping. It seems to be a decent balance between people throwing out cases unnecessarily and me losing money spending time to fix case halves...
I just might have to PM you about a repair.
As to the O P, there is ther outside chance that it is leaking between the case halves on the sealing surface, still have to split the cases. Use ONLY a Blaster flywheel puller, and somewhere there is a thread on how to make a case splitter, member Blaner posted it. I:I
Feel free, you know where my PM box is. I generalize and say $50 for most breaks and most anything under the size of a quarter is the same price. If it requires A LOT of reconstruction, the price can go up from there.
I've considered putting my cell phone number out there so people could call and discuss stuff but I hate to admit it; if my cell phone rang at 2am and it was someone wanting to talk blaster stuff, I'd have to cuss them like a dog...
Update for those who are helping me... Cracked cases, both motors!!! I don't have the motor that was in the quad torn down all the way, but I can see the crack just in between the crank. The cracks are on both cases and cross over the sealing surface. Fun times. Plan on making a splitter and welding up the cases. Splitter will be made from channel and all thread.
Question, do u need a special tool to assemble crank into cases? Or will the case screws sinch it down?
Question, do u need a special tool to assemble crank into cases? Or will the case screws sinch it down?
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