Gas Boils in Carb after Engine gets Hot

[86Rrider]

Guys- please point me to the right spot if this has been discussed before, because I've tried searching for a couple of days now and cannot seem to guess at the key words to find it:

I picked up a '84 ATC200S at a garage sale last year. Over the winter, I collected the missing parts, cleaned, pained and repaired what was needed and ended up with a pretty nice looking machine. The trike ran when I bought it, but was leaking gas from the float bowl to carb body joint. I took the carb apart and previous owner put silicon on the float bowl O-ring! So I got a rebuild kit, clean, blown, boiled the carb to make sure all the silicon pieces were out. Reassembled with the entire trike and starts on the first pull! Runs good and strong.

The purpose of this was to take this trike up to the family cabin and leave it there for yard work duties and trail riding when board. So, it went up over the Memorial Day week-end. I used it the first 2 days to pull a trailer around, moving trees I had to cut up that fell over the winter. Again, starts on the first pull every time and runs like a champ! The third day, my daughter wants to ride her LT80 around the trail on the property, but wants me to ride too. I fire up the 200S and away we go. Now, I'm doing about the same 5 ~ 8 MPH as I was hauling the wood, but this time it's sustained for about 40 minutes. I come around a corner and the engine bogs and stalls. It will not re-start and there is gas pouring out the carb vent hose.

I pulled the plug and it was black and wet - indicating running rich. I cleaned the plug, checked the spark - OK, tried starting again but no go. Gas started running out of the vent hose as soon as I turned the petcock back on. I let the machine set over-night and the next morning it fires right up on the first pull and no gas coming out of the vent tube.

So, did I experience the carb getting so hot that the gas was boiling in the float bowl and flooding the engine? Or am I dealing with a rich pilot jet of needle setting? Has anyone ever had this happen to them before?

I've not had this happen on my ATC90 before, running the same conditions. I also previously had a ATC200X, but never rode that slow, so cannot say I ever experienced this with that machine. Otherwise, I have all 2-strokes. So this ATC 200S is the first "big bore" 4-stroke I have owned in quite a few years. Thanks for any advice anyone can offer.

[Mackus84]

Sounds like your float is sticking and letting in way too much fuel. Im no expert, but thats my opinion

[83ATC185]

^^my first thought as well...

[shortline10]

Just as others have stated you have a float valve issue , install an inline fuel filter on the fuel hose and clean the carb . Probably have trash stuck in the float valve .

[yaegerb]

Guys- please point me to the right spot if this has been discussed before, because I've tried searching for a couple of days now and cannot seem to guess at the key words to find it:

I picked up a '84 ATC200S at a garage sale last year. Over the winter, I collected the missing parts, cleaned, pained and repaired what was needed and ended up with a pretty nice looking machine. The trike ran when I bought it, but was leaking gas from the float bowl to carb body joint. I took the carb apart and previous owner put silicon on the float bowl O-ring! So I got a rebuild kit, clean, blown, boiled the carb to make sure all the silicon pieces were out. Reassembled with the entire trike and starts on the first pull! Runs good and strong.

The purpose of this was to take this trike up to the family cabin and leave it there for yard work duties and trail riding when board. So, it went up over the Memorial Day week-end. I used it the first 2 days to pull a trailer around, moving trees I had to cut up that fell over the winter. Again, starts on the first pull every time and runs like a champ! The third day, my daughter wants to ride her LT80 around the trail on the property, but wants me to ride too. I fire up the 200S and away we go. Now, I'm doing about the same 5 ~ 8 MPH as I was hauling the wood, but this time it's sustained for about 40 minutes. I come around a corner and the engine bogs and stalls. It will not re-start and there is gas pouring out the carb vent hose.

I pulled the plug and it was black and wet - indicating running rich. I cleaned the plug, checked the spark - OK, tried starting again but no go. Gas started running out of the vent hose as soon as I turned the petcock back on. I let the machine set over-night and the next morning it fires right up on the first pull and no gas coming out of the vent tube.

So, did I experience the carb getting so hot that the gas was boiling in the float bowl and flooding the engine? Or am I dealing with a rich pilot jet of needle setting? Has anyone ever had this happen to them before?

I've not had this happen on my ATC90 before, running the same conditions. I also previously had a ATC200X, but never rode that slow, so cannot say I ever experienced this with that machine. Otherwise, I have all 2-strokes. So this ATC 200S is the first "big bore" 4-stroke I have owned in quite a few years. Thanks for any advice anyone can offer.

Either your needle valve is stuck or floats are set wrong. Try tapping on the float bowl with the end of a screw driver and see if you can unstick the float.

[jeswinehart]

Unless the carb to head insulator has been eliminated somehow (#9) your carb can not get hot enough to boil the fuel. If it has been replaced with some sort of all metal "adapter" of some sorts it probably is boiling after several minutes of operation.
Heck,,, maybe you have a couple of issues going on ?
http://www.bikebandit.com/oem-parts/...m1894#sch11193

john

[oscarmayer]

get a new carb. you can get a 24mm mikuni off ebay that will drop in for around $50 shipped. your carb probably has all the hols plugged with silicone for all kinds of stuff. somehow i get the feeling that carb will never be right.

http://www.ebay.com/itm/MIKUNI-CARBU...xWIwyA&vxp=mtr
$34 shipped. good deal!

[86Rrider]

Thanks for the idea's guys!

When the gas was running out the vent tube the first time, that was the first thing I did was grab a 3/4-inch dia. limb off the ground and tap on the float bowl. However, this did not affect it at all.

John- I cannot get to your bike bandit parts diagram here at work, due to the extensive internet firewall software we have. I'll have to look tonight at home. I believe that if you are referring to the rubber intake boot that has like a fiber spacer where it bolts to the cylinder, then yes that is there. If it is something else, I'll have to wait and see. I was not thinking that the engine was heating the float bowl, but the muffler. It sits a lot closer to the float bowl than the engine is. Is there a heat shield that missing between the carb and muffler? The heat shield that is welded to the muffler is there, but that sits back a ways from the carb.

Thanks oscarmayer for the ebay link. I'll look into that possibility as well. I know you cannot guarantee you can ever get all the silicon out once it gets in there.