checking for air leaks

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zepplin153
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checking for air leaks

Post by zepplin153 »

rough running KDX 200. I think I have an air leak somewhere on the intake system. Here is what i have done and can rule out:

- compression check (150)
- Jetting will not make it go away. (yes i have followed the jetting guide. I think I have it memorized). plus i think whatever is going on is effecting my ability to jet properly.

I have also been getting some milky stuff in my carb. I run ethanol free gas too so its not my fuel. I think its an air leak. all sighs point to it. So how can I find it? Just start replacing stuff until it goes away? if so where do i start?

Here is one other thing i have done (feel free to make some jokes) with the throttle cable/cap on the carb I covered my hand over the filter side of the carb and sucked on the reed side and was able to draw air in. I heard it too. Not sure if there is supposed to be any air coming in through there but I suspect it is not.

Any input?
'98 KDX 200 (KLX300 Forks)
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G22inSC
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checking for air leaks

Post by G22inSC »

I would start with both a pressure test and vacuum test. They will check your crank seals, cylinder gasket, head gasket, reed block gasket, etc. Not hard to do with a few tools and adapters to block off the intake and exhaust. It would either give you piece of mind everything is ok or help you locate and identify the possible air leak.
'05 Kaw KDX200 ('00 KX125 forks / '02 RM125 Showa "K2" shock)
'14 Yam YZ125(x) (oldest boy's)
'22 Yam YZ125X (youngest boy's)
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'10 Honda Recon (wife's)
'08 Kaw KX65 (Sold)
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bufftester
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Re: checking for air leaks

Post by bufftester »

Generally, the milky white stuff is water mixing with the oil in your premix, very common on PWCs that have a tendency to suck water. On your bike there are a couple of likely culprits. First is the fuel tank, easy enough to add some drygas additive, or drain and dry your tank. Make sure you aren't over oiling your filter. Check your intake boot for cracks, and ensure the filter is sealing against the airbox when installed. Easy way to find air leaks is to spray some carb cleaner around the suspect areas while the bike is running. Sucking on your carb you might be able to pull some air through the threads of the air screw, some folks have fitted an o-ring to it to help seal, I use a dab of teflon tape. You could also be pulling air through the cap where the throttle cable enters, but it shouldn't be enough to muck things up unless your carb is badly worn or damaged.
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