99 xr100r bogging issue

[black]

Neighbor brought his kids bike over
"Says" it ran fine before, now bogs in 2 and 3 when rolling throttle
Confirmed it after 2 kicks to start it
Tool carb off it was putrid.
Carb dipped , sonicator etc. new. Gaskets new carb hardware , float needle didn't even have rubber on it anymore. Replaced that. It was / seemed to be missing that little white dish in the float however. Ordered oneand waiting but still tried to start it

It still bogs. Also felt like the slide was not going back known sharply enough when you rolled off the throttle and riding it and while parked and running. But it does when the slide is off the carb
Idle screw is set right just enough to keep it running nice but not dying.
Theix screw is 1. 5 turns out after being seated lightly. I've tried running it 2, 2.5 and 1 to fully seated . No affect on bogging and it runs.

Took a guess and took off the air filter , filter seemed a little dirty and slightly tacky with oil.

It ran better with a little stumble but not perfect.
I'm stumped for next step
Clip is in middle position of needle. All hardware acctd for in carb no missing gaskets , needle jet holder is in correct orientation.

Thoughts?
I don't want to get into anymore honestly. Maybe a valve check
But that carb is pristine now.
It's beat up. Ductape around the rubber exhaust female end as it's torn. Etc..

Ordered a new carb from Amazon see if that will make a difference

It runs better with out air filter so it gets more air to burn the fuel better. So why didn't messing with the mix screw before that help?

Float height might be something as maybe it's getting too much fuel...and then giving more air ( taking air filter off). Runs better but not perfect.....?

PS. This is all new fresh gas, not old there is a fuel filter on as well

[boosten lebaron]

I would adjust the valves real quick and drop in a new plug and see how it goes.
Check the intake boot really carefully for rips.
The mixture screw shouldn't really be a trial and error game. Set it to idle fast and best and that's it. 1.5 is probably close though.
Is the return spring weak causes the slow return?
The jets are correct right?
Set the float height correctly.
Check the choke system to make sure it fully opens and closes.

[breakdirt916]

[noob] sounds like it’s not getting enough gas or has a ground issue/loose connection…pop off the gas line; is it flowing fast out of the fuel petcock?

Got a video by chance?

And from how dirty the carb was, it almost sounds like you should go through the bike

[butcher bergs]

How old is the spark plug?

Is it the correct one?

[jimmycapp]

Is the muffler clear? Had a friend chasing the same bogging and we did similar steps with almost no change. Eventually found spark arrestor in muffler packed solid.

[joeswamp]

Another possibility is clogged intake. If the bike has been dumped and the paper air cleaner gets saturated with oil, you end up with symptoms very similar to a clogged muffler.

[OreoGaborio]

Is the muffler clear? Had a friend chasing the same bogging and we did similar steps with almost no change. Eventually found spark arrestor in muffler packed solid.

A buddy of mine went through this exact thing and found that to be the issue as well.

Granted it was a 2 stroke so it may be a bit more sensitive to that kind of an issue, but the way I see it, if an engine can't exhale, it probably can't inhale.

[black]

Waiting for a part. The little white thing in the float . Then I'll try it. Reclreclean the pilot circuit. I think with it being so touchy with the mix screw, it running off the main circuit not pilot. Maybe increase the pilot jet or change needle clip position. Especially since more air seems to make it run better ( ran with air filter off)

[breakdirt916]

[noob]yeah that sounds like a carb thing

so my guess is that it's not getting enough gas in the pilot circuit. All you're doing is raising the slide enough for it to run. is the "mix screw" angled in the carb? got a picture of it?

[jimmycapp]

Any updates

[klp]

Have you verified compression? Might be chasing your tail on carb issues.

[black]

minor update.. never got to trying other pilot jets. it was a chinese carb, i told him to buy a honda carb and we could troubl shoot a little more. he said that it has always bogged. for 150$ a stable baseline with oem jets is a goo starting place vs spending 2 hrs trying different pilot jets. current jets arent' lablled.

[typeone]

haven't caught up here but good move on the OEM carb. the Chyna carbs can be a f'in bitch to tune sometimes, especially with a 4T.

will be interesting to hear how it runs with a proper carb + jets but the duct tape... was there more of it used on the intake boot? how is the header > cylinder connection?

assume new plug, also assume valve check were both done?

[black]

no valve check done.... more items on the plate right now.. this week i'm working on my own Xr100

tried to help a buddy but onc eit turned into 5 hrs and cost me time for my own projects, i passed on it.

[typeone]

no valve check done.... more items on the plate right now.. this week i'm working on my own Xr100

tried to help a buddy but once it turned into 5 hrs and cost me time for my own projects, i passed on it.

hear that ... always tricky working on a buddies bike you're not totally familiar with. 'why doesn't it work?' ... 'uhhh'

[black]

hear that ... always tricky working on a buddies bike you're not totally familiar with. 'why doesn't it work?' ... 'uhhh'

its still at my place.... lol I need to get my own xr100 done next week to sell hopefully.