Buddy runs for ~5 mins, cuts out - Autochoke/Enricher/Bystar

buddys_n_blasters · Post by **buddys_n_blasters** » Wed Jan 23, 2019 5:00 pm

Wanted to post this to get some input. Not sure if the right fix but it definitely worked.

Recently bought a Buddy 50 on the cheap because the owner thought it had carburetor issues. The bike would start easily, rev all the way up and down, and could even be ridden for about 5 minutes, after which it would slowly bog out.

Turns out the bike was tuned for summer riding and I was trying to ride it in 20 degree winter days. The autochoke/enricher/bystarter was dumping in fuel upon startup and giving me a good, rich mixture. After about 5 minutes the autochoke would close up, so the mixture leaned out and the bike died.

The fix: I played with the air/fuel mixture screw on the carb and brought it from 1.5 turns out to only 3/4 turn. Fixed the problem completely. The bike now revs, rides, and idles great

I'll move the screw back to 1.5 once the warm weather comes back.

Dooglas · Post by **Dooglas** » Wed Jan 23, 2019 6:05 pm

Sometimes you will see that symptom with a partially or completely clogged idle jet as well. Good job of troubleshooting.

BuddyRaton · Post by **BuddyRaton** » Thu Jan 24, 2019 12:35 am

Nice job!

sc00ter · Post by **sc00ter** » Thu Jan 24, 2019 3:52 am

The Buddy 50's came with a air/fuel screw? My 2009 didnt have one. Anyways, I would still consider cleaning out the carb and jets. Good job getting it running.

tenders · Post by **tenders** » Thu Jan 24, 2019 4:05 am

My 09 Buddy 50 definitely has the adjustment. Itâ€™s a screw with a D-shaped head that requires a special bit to turn. And it has a red benchmark inked on it to show it was adjusted at the factory.

buddys_n_blasters · Post by **buddys_n_blasters** » Thu Jan 24, 2019 2:50 pm

sc00ter wrote:The Buddy 50's came with a air/fuel screw? My 2009 didnt have one. Anyways, I would still consider cleaning out the carb and jets. Good job getting it running.

Mine is a 2008...I'm pretty sure what I moved was the air screw. It wasn't D-Shaped though. I've never heard of a carburetor without one to be honest, but I am new to this.

tenders · Post by **tenders** » Thu Jan 24, 2019 3:26 pm

The other adjustment on the carb is the idle speed screw, which on my â€˜09 has a plastic thumbwheel on it for easy manipulation without tools. Not sure if this would have solved your issue, or if that was what you actually adjusted, but you canâ€™t do much damage messing with it.

You CAN potentially tweak the air/fuel mixture ratio screw to make it too lean, which can over time and hard running, burn a hole in the piston. This is further complicated by the fact that in some carbs, that screw controls air flow, while in other carbs, that screw controls fuel flow. As a result, â€œrighty/tighty, lefty/looseyâ€� can mean completely opposite things with respect to the mixture. Thatâ€™s probably why many are made with a weird head, to be more difficult to adjust, and marked as set at the factory. Some carbs have caps over this screw to further discourage user wrangling.

sc00ter · Post by **sc00ter** » Thu Jan 24, 2019 4:24 pm

Crazy air/fuel screws. On 2 stroke Zuma's they have a welch (spell that right?) plug over the air/fuel screw, and we just remove them. My 09 Buddy didnt even have that. Nothing, nada. Was told to get a RoughHouse carb for the Buddy 50. It idles "good enough" now that the carb has been sonic cleaned. Still a great quality little 50cc.

buddys_n_blasters · Post by **buddys_n_blasters** » Thu Jan 24, 2019 6:27 pm

tenders wrote:The other adjustment on the carb is the idle speed screw, which on my â€˜09 has a plastic thumbwheel on it for easy manipulation without tools. Not sure if this would have solved your issue, or if that was what you actually adjusted, but you canâ€™t do much damage messing with it.

You CAN potentially tweak the air/fuel mixture ratio screw to make it too lean, which can over time and hard running, burn a hole in the piston. This is further complicated by the fact that in some carbs, that screw controls air flow, while in other carbs, that screw controls fuel flow. As a result, â€œrighty/tighty, lefty/looseyâ€� can mean completely opposite things with respect to the mixture. Thatâ€™s probably why many are made with a weird head, to be more difficult to adjust, and marked as set at the factory. Some carbs have caps over this screw to further discourage user wrangling.

My Buddy also has the plastic thumb screw for idle, so I know I wasn't messing with the idle then. That really only leaves the air screw to be the one I played with.

I hear you on the air screw vs. fuel screw thing, it's confusing. I usually just screw it all the way in one direction and let it run for a second. If it smokes like crazy I know that's a rich condition and it must be an air screw. You can also just look and see what that screw does if you have your carb off the bike.