Sno Scoot won't run properly

phazernut

phazernut

New member
Joined
Feb 9, 2007
Messages
38
Age
56
Location
Torbay, Newfoundland
I have an 88 scoot. It starts fine but it won't run well past 1/4 throttle. Ive cleaned the carb and have done every thing with the screw on top of the carb. Nothings seems to help. It's like its loading up with fuel. Right of the start it takes the throttle and takes off fine...then it starts to load up and won't speed up at all. Just sputters and eventually won't take any throttle at all. I'm thinking about taking out the reeds to see if there is any trouble there. Before I go any further I wanted to see if anyone here can offer any suggestions. The oil injection is disconnected and I run mixed gas at 50:1.

Any suggestions...my 5 year old is getting anxious
 

You may have to get a new carb. Is it hard to start? If it is hard starting and running like that do a leak down test to rule out a crankcase seal. Check all the cheep stuff first. Fuel filter? Fuel pump? All hoses? Jetting? If you know someone with an ultra-sonic parts cleaner have them throw your carb in there for a few days to get it good and clean. There is also a chance your clutch is not shifting right.
 
It's not real hard to start. Someone installed a primer on it and I usually prime it 3 times and kick it over. I have to hold the throttle to get it to start but once it starts it usually just idles fine. There is all new fuel lines on it and I removed the fuel filter completely for now. I filter the gas going in the tank. The fuel pump is not an original part. It is a regular mikuni pump not the yamaha pump. I assume that makes no difference. It was on it when I bought it. When it is shut off it takes 2 kicks to get it going and I have to hold open the throttle. For the running my little guy does right now it actually works OK as it is not real fast and won't get him in trouble but I want it to run like it should.
 
I would get a filter back in the tank. It doesn't take much to plug up them little carbs. What about your jetting? Have you looked at your plugs?
 
I have an inline filter on it this morning. I changed the plug as well. No difference. It is fouling the plug though. Would the fuel pump cause this if it was on the way out?
 
Fouling the plug. Is the jetting set for your altitude? Take out your air filter and see how it runs without it. If the filter is dirty clean it or get a new one.
 
The sled spent its entire life here in Newfoundland so I doubt there is a jetting issue. I have a new air filter on it. It seems to be loading up with fuel. I disconnected the choke today and it ran fine for a while. Then it started loading up again. Whoever had it before had butchered the inside of the carb. I had the float boal off today and the screw for the float is stripped and the piece holding the float in place appears to be JB welded back in place....I think a new carb may be in order.
 
Hmmm. Since the float is rigged it is probably not adjusted right. You may be able to get it to run. It is real common to see them float mounts snapped off and glued back on. I would get a new carb while you can still get them. Since your into the carb, what size jet is in there? What is your altitude? typical daily temp for this time of year?
 
Can't get the jet out. I'm about 500 feet above sea level. Temp ranges from 0 - -15 celcious. I put the carb back on to get it running for the day. Little guy was not happy. Going to the local dealer tomorrow to see how quick I can get a new carb
 
Sea level to 2000 feet is a 103.8 main jet for zero degrees to -30. Above zero you can drop to a 101.3 main jet. I would go with the 103.8 since you are at 500 feet and check your plugs to see if you need to adjust. If temp drops to -30 the book calls for a 105 main jet. Your pilot jet should be a 62.5. Were you able to get a new carb? Hope your having fun.
 
I got a new carb...sort of...its attached to another scoot that I bought yesterday. The dealer wanted 400.00 for a carb...I only paid 1000.00 for the new scoot.It was like the day it came from the dealership......it also came with a spare carb so I'll put that on the other scoot and probably sell it. The little guy is very happy now especially since his new scoot has electric start and I don't have to start it for him.
 
wide open

Just a thought because sometimes it is passed on but have you checked the exhaust and made sure it's not partially plugged which in turn would make sound like it is running extremely rich.
 
Checked it as best I could. I took the rear half of the exhaust of and rode it. No difference. Unless its plugged in the front part which I doubt.
 
Sno Scoot

9 times out of 10 it is the carb. I have three carbs and only one Scoot. One of the carbs I have cleaned so many times I can't remember. I have replaced the jets, gaskets, etc. and it still doesn't run right. I bolted on a new carb ($235.00), and it has never run better. I don't understand it either.

If you can't get the main jet out you can try this; Order a new jet since you will probably mess up the one you are going to take out. Lube it up real good with penetrating oil (PB Blaster is great stuff) take a torx bit, I can't remember what size, and tap it into the top of the jet. Make sure it is real tight and then twist.

I and others have used this method numerous times with succuss everytime.
 
If it idles fine and then loads up at full throttle it is most likely the main jet. If the main jet gets reamed out to many times from cleaning it will get bigger and cause it to run rich. Another thing to check is that the rubber plug that covers the pilot jet is in place.
 
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