I bought a Yamot 150 about a month ago and had the opportunity to take it out 3 times so far. The kids love it, but our fun has been cut short the last two times. The last time ended up in a 4 mile tow.

The first time we took it out, it ran great but after a couple of hours it started to stall whenever allowed to idle.

The second time, after about an hour of riding, same problem, but after we took a rest, we could not get it started again. It would turn over and idle for a couple of seconds, and then die. Any application of the throttle and it stalled instantly.

That weekend, I took it apart to clean the carburetor. What a pain. I had to remove almost everything to get to the airbox and carburetor, and I believe it is impossible to get to the throttle idle adjustment without removing the gas tank.

I thoroughly cleaned (blew it with air and used carburetor cleaner) the carburetor and fixed the airbox. The hose from the carburetor to the airbox had popped into the airbox so no air was going through the filter. I trimed the hose about 1/2 an inch, and siliconed the connection between the airbox and the hose. Otherwise, I couldn't find anything wrong anywhere.

I put it all back together, and the test drive ran great. After warming up, I adjusted the throttle idle screw, and also the throttle jet screw. Everything was working perfectly, the only difference was about a 25% drop in power because now the intake had to go through that thick filter (K&N is a must).

So we took it out to the desert again, and we had a repeat. After about an hour of riding, it started to stall whenever idling. Then after a few stalls, it would not start at all. Towing that thing over four miles of rough dirt roads was not fun, so for the forseeable future, that thing is not leaving site of the camp.

I called Patriot and they said to disconnect the automatic choke or cut off the tappered portion of the long jet needle (not sure what the correct name is). They were responsive and supportive, and mentioned that the automatic choke on the 150s has been problematic. If that doesn't work, they'll replace the carburetor.

I am disappointed that I am restling (and spending time and energy) on a quad that only has about 4 hours of run time, but so far Patriot seems responsive so I don't want to give the impression that they are not working with me.

Nonetheless, I want to hear if anyone else has had similar problems, and if they have found a solution.

Does anyone know how the automatic choke works so I can disable it?

I am not an experienced motorcycle mechanic, so I am not ready to rip into this thing and reengineer any design flaws. Also, I have not given up on it, yet!

 

Dear Squirt:
I am sorry to hear about the problems you are having. #1 who ever sold you that unit should not be having you do all that work on it. I mean it is always nice to have someone willing to try and fix there problem, but it sounds like you have done a little to much! Patriot has been very good in supporting there Yamoto ATV's. But I really would suggest that they or the dealer you bought the unit from just send you out a different carb. I have had a few problems here and there with the carbs. I really think you should call Patriot or the dealer you bought the ATV from and just get a new carb and I think your problems will go away. If you cannot get any help with this please give me a call and I will help you out!
All The Best.
Kids ATV Raceway ATV

 

I wonder if you have a fuel filter on your model?

 

I am having the same problem with mine that I purchased for my wife. It does have a fuel filter and that does not seem to be the problem. As squirt noted, is seems to be an issue with the choke. The unit runs fineuntil it gets warm and then it dies. There seems to be plenty of fuel flow. If you let it get cold it will fir right up and go again. I have not figured out how to disable the choke. I will probably give patriot a call sometime this week and see if I can get this issue resolved. It would be greatly appreciated if anyone else has a solution to this problem.

 

I have the same problem with ours. After riding for about 15 min. and it's good and warmed up, if you let off the gas it will die, if you let off to about half throttle and then give it more gas it will bog down for a second before picking back up again.
When it dies I'll let it set for a few minutes and it will fire right back up, run for a few minutes and die again.
We've only had it out a 2 times, the first was for about 2 hours and never had a problem, it was almost 60 degrees out. The second was last weekend and the problem started after about 15 min. and it was 42 degrees.
I'm thinking it has something to do with the elec. choke also.

 

montecarlo97, and Buford77, I had the same problem with my wifes quad. Clean the carburator, use carb cleaner and compressed air. You need to be able to see light through all the jets. I dont think that these get put together in that clean of a environment, which lead's to dirt in carb. After cleaning install a fuel filter and dont let the gas get too old 3 weeks max. While cleaning the carb dont get ang carb cleaner on any of the rubber gasget's. They will swell up and be too big to use.

 

Interesting problems you fellas have, because mine is exactly opposite!!!! My 150 starts fine but won't idle until warm. This typically means starting half a dozen times or more and choking it by hand, as I have taken the junk air box off. Still waiting for the K&N to arrive. After it warms up this thing is strong!!! I took my son to the timber for some trail riding Saturday, his and the Yamoto's first trip. And this little thing just powers up the steepest of hills.
I'm taking it to a buddies this coming weekend and he's gonna "have his way with it". He says he is gonna rebuild the carb. I know he wants to re-jet it and tune it with the new filter. God only knows what else he's gonna do to it...he's a freak!!! I'll let you all know the mods and the results when we get it back. I'm really just hoping he can make it start and idle every time!!

 

Well I found the problem we were having with my wifes 150. After disconnecting the choke and cleaning the carb, I stumbled across the fact that when it died there was no fuel flow out of the tank. I took off the gas cap and the fuel began to flow. After removing the hose from the top of the cap, I noticed there was no hole to allow the vent to function as it is designed. I grabbed an awl and poked through where the vent hole is supposed to be located. It runs like a champ now. HTH.

 

Glad to hear you fixed the problem Buford77, one more thing for owners of these quad's to take a look at.

 

Picked the 150 back up today and I'm not impressed. It was about 12 degrees here today and the Yamoto wouldn't stay running. After three or four restarts it wouldn't even fire. When my buddy removed the carb and cleaned it, said it already looked good but did it anyway. He also put the K&N on it. He also noted that the selenoid that works the automatic choke tested fine. The whole week he had it, daytime temperatures were mid 30's to mid 40's and it started and stayed running fine after adjusting the idle mixture screw. The machine would never go into a high idle to indicate the choke worked at all. He believes this would be an electrical output problem to the electronic choke, but had no way to prove it other than that the selenoid worked fine alone. He did say it ran great once it warmed up and seemed very responsive and had good power.

So, guys, now what? Where do I look now? Any ideas?