We have a 2007 Eton Viper 90R (4 atroke) which has just recently been bogging down when you give it throttle going up a hill, and also if you get going full speed downhill after about 30 seconds or so it starts to bog and smoke billows out of the exhaust. I had a friend look at it who is good with small motors, and he got the carb off but could not get the bottom off due to ceased screws. He said it was a weird carb, and looked like a "pretend Mikuni", so I am thinking of replacing it with a real mikuni.

Does anyone have any idea what the problem is? I am using conditioned gas, and also added about 1/2 tank of fresh conditioned gas, (which did not make a difference), but the dealer (Switzer Motors in Whitby, Ontario) says that theses Etons are so finicky that you have to use absolutely fresh gas (not even 2 weeks old) or they will not run right. (The distributor also told me just today that the smoking may be caused by too from too much oil in the crankcase, but I have not added any. He also said a Mikuni would probably run worse!)

Any advice would be much appreciated, including advice on how much a new Mikuni would cost (if I can get one with the right specs!)

 

excuse me, but what is conditioned gasoline?
find a penetrant called AeroKroil. spray the seized carb screws with this. it'll loosen them up in about an hour. that's the best stuff on earth.
what color smoke?
bogging = dirty carb/jets
today's gasoline has ethanol--easy to gum up after sitting for a while.
carbs are easy/cheap to replace if you can't get it apart.
let us know.

 

Hey, Jaster94, thanks for the reply. By "conditioned" gas I mean with fuel stabilizer added, and BTW Rob at our local marina, sells gas without any ethanol in it.

I'll try to find some Aerokroil, thanks for the suggestion.

The smoke is white, and it happens only intermittently (every 20-30 seconds), and lasts for about 5-10 seconds.

BTW the local Eton distributor said a new carb would be $200 - well the whole ATV is probably not worth more than $1,000 at this point, so if anyone knows where I can get an Eton carb cheap, can you please let me know?

 

"sells gas without any ethanol in it"
Hmmm, My buddy which owns a gas station told me that all fuels have ethanol now (like 10%).
Call Hetrick Racing, they can help with a aftermarket carb and such.
I disagree with the "2 week old" statement. They are not that touchy and why should they be.
IMO, I'd be checking the valve adjustment and valve seals.

 

Thanks, LT80. I will check out Hetricks, and also see about the valves.

BTW, it is rare to find ethanol-free gas, but my marina has a special arrangement with Petro Canada to get it, so we are indeed pampered with our small engines!