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Eton Viper Jr. Carb troubles

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Old 03-30-2017, 07:20 AM
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Default Eton Viper Jr. Carb troubles

Hey guys wondering if anyone could help me out, have a eton viper junior 41.5cc 2 stroke engine in the process of trying to get the thing running. I've cleaned the fuel tank checked the compression and made sure it was getting a spark. Took the carb apart and let the parts soak in diesal overnight put it all back together cranked it up ran perfectly then stopped and couldn't get it restarted, then it started to leak gas at a slow drip. Took it back apart and recleaned everything, the exact same thing happened tried this about 3-4 times. I believe the float is getting stuck or the float needle isn't stopping the fuel coming in? It's a single donut style float that sits on on brass float arms the carb is 16mm and the parts are almost impossible to find and the rebuild kit is from eton says not for OEM carb. Any suggestions on what to do or if y'all have any other ideas on what it could; because I am stumped.
 
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Old 03-30-2017, 08:26 AM
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Old 03-30-2017, 08:58 AM
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The compression was right around 110, so I'm guessing that is good; unless I'm converting the 6.6:1 compression ratio wrong. I really wish I could get this carb working, might have to look into buying a new one though thanks for the link.
 
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Old 03-30-2017, 02:57 PM
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If a compression gauge went up to 110 it should be fine.
Don't have a clue an that 6.6:1 thing.
 
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Old 03-31-2017, 02:16 AM
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Natural air pressure is roughly 15psi, (goes up and down a bit with weather and altitude). If you multiply the compression ratio 6.6 by 15 you get 99psi. Seems fairly low, most four strokes are above 9 to one, but you loose a big chunk of stroke with the ports being open on a two stroke.
 
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Old 03-31-2017, 12:51 PM
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100 psi is usually enough to allow any gas engine to run.

it started to leak gas at a slow drip.
Could be the float valve leaking or float height too high.

But here's a problem I've seen on many different carbs from tiny carbs on 50cc bikes to huge Holley 4 barrels.

A clogged air bleed can cause a siphon situation where fuel either drips from the overflow, or runs into the carb throat. Sometimes just covering an air bleed with your finger will cause fuel to flow out. Air bleeds function as a siphon break in some carbs.

Air bleeds are small brass ***** staked into a hole that allow a small amount of air to pass through. You'll see them on the sides and/or throat of most atv/bike carbs, and down in the throat of auto carbs.

I'd suggest soaking in a carb cleaner and hit the air bleed(s) with air afterward. The diesel probably didn't dissolve much crud.

Many carbs with clogged air bleeds have been tossed in the trash due to the "internal leak" and "porous body".
 
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Old 04-03-2017, 08:30 PM
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Thanks for all the tips never did check the air bleed, but does make a lot of since; I did adjust the float arms some didn't seem to make any better. The float valve seems to be not sealing correctly. Yea I've always gotten away with just using diesel for cleaning carbs, but also never worked on two strokes much or any engine this size; definitely will try soaking in carb cleaner. Will let y'all know how it goes
 



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