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Post by ewasleske on May 27, 2015 12:09:32 GMT -5
Hi guys, my current project is CL deal. 2007 fact owned (and neglected) by a college kid. This scoot was covered in mud and grime. So first step- tear down and clean and begin parts and repairs. Turns out it has an Airsal cylinder installed! The carb has a 70 main, I lowered the clip one notch. Will it hurt to run without upjetting? I idled it last night for 15 mins. The pipe was only warm to the touch. Exhaust leak? There also seems to be oil dripping from the air cleaner..what might cause this?
Your comments and help are appreciated!
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Post by Fox on May 27, 2015 13:04:37 GMT -5
2 strokes will actually spit some oily gas out of the carb throat toward the air box. Eventually the filter gets saturated and it will drip out. The remedy is to clean the air filter element regularly so it doesn't get too saturated. Usually it's a foam piece that can be washed with dish soap and water.
As far as the jetting: Take the spark plug out and look at the color of the tip/electrodes. They should look brownish. If they are light gray, whitish then you need a bigger jet. If they are black and sooty then you are a bit rich.
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Post by ewasleske on May 27, 2015 19:59:41 GMT -5
Thanks Fox. I will have to ride to check the new plug. Old one looked oily. Maybe the oil feed needs adjustment.
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Post by niz76 on May 28, 2015 0:33:45 GMT -5
Assuming the scoot has the stock carb, stock airbox (snorkel in? or snorkel out?), and stock exhaust, it still seems that a 70 mj may be a little small... Of course, there are tons of factors that affect carb jetting like elevation, temperature, etc. so no two setups are alike. I would take Fox's advice and do some research on reading the spark plug. Keep in mind that the carb works in many different stages like idle, partial throttle, wide open throttle, etc. so if you simply put a new spark plug in and just go out riding, you'd see the effects of all the different settings of the carb when you may just be trying to evaluate WOT and the main jet for example. Maybe your idle circuit is a bit rich, but wide open throttle (main jet) is lean- you won't really know by looking at the plug since the idle circuit may have been the setting to give it good color... This is why we do "Plug chops". Always err on the rich side and run as big a jet as possible without hurting performance! (Again, I personally think a 70 mj is a little small for a BBK).
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Post by ewasleske on May 28, 2015 8:15:30 GMT -5
Thanks for that clarification. This will be my first attempt at a tuned scoot since the bbk is on already. I'm nervous about the aluminum cylinder since I have read they can seize easier. It appears the previous owner installed the old head- any issues there?
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Post by 90GTVert on May 28, 2015 15:31:39 GMT -5
If you mean there's a 49cc head on it, it could be too small so compression would be really high. If you can do a compression test it's an easy way to get a rough idea if it's alright. You usually don't push too far beyond 180psi. Sometimes even that can be too much.
Keep it on the rich side and you should be alright. Start with a jet you think is too large and work your way down rather than starting small and working up.
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Post by ewasleske on May 29, 2015 10:20:52 GMT -5
I just assumed he used the old head because the box of parts that came with the scooter included the old cylinder and a brand new aluminum head. Can I tell by looking at it if it is a 50cc or 70cc head?
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Post by filip on May 29, 2015 11:32:34 GMT -5
you can from the inside
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