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hello whats everyone doing with the crank breather that goes into carb? found a one way valve from ktm should i install and then put a little filter on end of hose? dont really want hot vapors going into carb and diluting intake charge any suggestions would be helpfull thanks
 

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hello whats everyone doing with the crank breather that goes into carb? found a one way valve from ktm should i install and then put a little filter on end of hose? dont really want hot vapors going into carb and diluting intake charge any suggestions would be helpfull thanks
Here's what I am using:
http://www.speedpartz.com/uni_crankcase_vent.htm
I just plugged the carb nipple:
http://store.nutsandbolts.com/rubber-caps-...oses-lines.html

You can find these rubber caps at Home Depot or Lowes....
 

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I'm using a Thumper Racing one way check valve, spendy but worth it..
 

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I have the one you are talking about - https://www.ktm-parts.com/mm5/merchant.mvc?...;Category_Code=
Works a treat. I cut it into the crank breather hose up behind the side plastic and then vented it down the back of the motor with the carb overflow lines.
No filter required because it only lets the preasure out. It won't suck back.
The other problem with running a filter on the end of the crank breather hose is that the filter will block up with oil after a few months, and then let nothing out of it.
I know, it did it to me and preasurised the crank case. One real fast way to do some damage.
I was lucky as I lost my clutch before any seals were blown.
 

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Driver and I dyno'd the thing, Like I said before we'll dyno anything, we found no gains with it open or hooked back up to the stock location, so I left it hooked up to the carb (just incase it failed)
 

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You can buy one of these one way valves in 10mm, 8mm, 5/16, 3/8, 1/4 off ebay used on gas and diesel engines as a crankcase vent and they run anywhere from $2.00-$55.00 shipped. I understand how they reduce stress on the engine, but thumper actually believes it increases horsepower. Doubtful and doesn't according to our buddy ranchero. If you get one of these valves off ebay you still have to get the block off for your carb or just put it in line with your carb.
 

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I think on the 530 engines, which have a separate crank to gearbox oil setup, they would be allot more prone to heavy breathing, they don't have the gearbox volume to dilute the engine rotation pulse, and hence why these engines (530s) have a hard breathing issue.

normal low buck automotive PCV vents aren't the greatest quality........

just my thoughts.....
 

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These aren't pvc valve actually... A pvc valve is just a flapper type check valve and will not work for something that would be flipping back and forth so quickly. These are diaphragm type just like the ones by thumper. They "trip" at 1.5-2lbs, which would be perfect for anything 400cc and above. Look much like the ones issued by ktm. I have one from KTM, I was just putting in my input. People trust them on their multi thousand dollar Hot rods.... So I guess it'd be alright to assume they would suffice. If you watch thumpers video there one way trips at approximately 2lbs as well.
 

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If anyone would trust a 2 dollar diaphragm one way to protect their engine they deserve to blow it up IMO. I was just giving and accurate starting eBay price for the valves themselves. The reputable ones with and accurate/consistent trip ratings are starting around 25-30 dollars. I personally wouldn't pick the thumper racing valve over the KTM valve and the KTM valve is less than half the price.
 

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I bought the Thumper Racing valve too!
 

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I've had both the KDS and the Thumper Valve. I lost the KDS out in the dunes so now I have the thumper valve and am pleased with either or. I have never seen the kTm version of the valve so I can't comment on it.

Brian
 

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anyone else ever experiment with using the exhaust flow to eliminate bottom end pressure?
 

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anyone else ever experiment with using the exhaust flow to eliminate bottom end pressure?

I have often thought about doing this and think it would be an awesome way to create a vacuum in the engine. I think it would be tricky to find a way to keep engine oil from getting sucked up through it though. I dont think the current engine case design with the lower breather tube outlet would work very well with a constant suction.

Brian
 

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we shall see real soon, haha ;)
 
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