Had an unusual problem yesterday. The local John Deere dealer brought a KLF300 quad to us. They had tried to fix it, spent a fortune, and still couldn't get it going. I checked for a spark and it had one. Tried a new plug and it fired up, but ran very badly and wouldn't re-start, it also dribbled a little fuel out of the airbox. They had fitted a new genuine carb but, with the dribbling, I thought it best to remove and clean it. Nothing wrong, except the big plastic breather pipe from the top was connected to the carb drain tube at the bottom. A proper step down plastic connector had been used, but this was obviously wrong, and the engine ran fine with them parted. Why had someone done this? Do new carbs come with these tubes connected together to keep dirt out?

 

Polaris did that for years on their two stroke atvs using a tee to connect the atmospheric vent tubes and carb bowl drain tubes together. Any time I tore into one,I threw the tee away and rerouted the vent tube up under the tank and zip tied it to the choke or throttle cable.To me it's a stupid idea to do this and with the one way check valves that most had on the end of the drain line seems like all that would do is restrict air flow into the carb plenum chamber. Guess it was designed to to keep dirt and water out,but someone wasn't thinking right at the factory imo.I'd route the lines separately and go from there on your checks. Her's an example of what Polaris did.

 

I have seen this same thing a few times....on new OEM and with the "knock offs" carbs as well. I have always thought that was simply how they shipped them....and to keep any hoses from "dangling around" .

 

I was thinking back, and in over ten years of working on Quads every day, I've never fitted a new carb. Very rarely, part of a rebuild kit, and the occasional diaphragm/slider assembly. I have been tempted to buy new carbs for Suzuki LT50s, in my experience, the most difficult carb to get "right".

 

^^^^^ I have worked on a couple of these and the problem I had was obtaining the correct idle rpm. What I had to end up doing is setting the idle adjuster screw to one spot ( leave it there ), then use the air/fuel mixture screw to actually set the idle speed..... Is this what your talking about?

 

Bought my son a new first year model 84 Lt50 and had to remove the restrictors real quick. The main one was the reduction washer in the exhaust that everyone has to remove as it chokes down the machine.Don't know if Suzuki still has those on the later models,but have noticed even up to the 98 models they still had the piggy back pilot jet(second restrictor) that a lot of people don't think about. If it's still in there carbs can be a pain to adjust right. Take this restrictor pilot jet out and chunk it if you find a carb that still has one in it. Wouldn't have thought about this until I looked again at the owners manual and it mentioned removing it also. Carbs should be easier to tune then. Item #3 on the parts breakdown.

 

Nope, it is that strange upside down float needle that gets me, it has an odd little wire clip that is always worn, and sometimes missing, as is the washer 17, which throws the float level off. Priced new float needle assemblies up, and they cost a lot more than a new Chinese copy carb.

 

Oem parts are crazy compared to what the knock off carbs are. You can get a new Polaris youth model carb for the same price as what an oem needle and seat costs also.Actually for over 50 bucks for the needle,you can get TWO Chinese knock off carbs on ebay.