[Piranahbite]

what's up guys, I have an old 84' Dr100 a friend gave me, they let it sit out uncovered for 15 years. i got it running, the jets in the carb were clogged i cleaned them out and made sure fuel could get through all the holes. it still wont run right though. it has issues with bogging down until your going about 15mph then all the sudden it clears out. i tried adjusting the fuel mixture screw and the idle screw but neither change how it runs. i was wondering if you guys could help me source a new carb, or help me with my current one. only things iv done to it were clean out the jets, free up the cable, and solder a hole in the float closed any help would be appreciated

here's the bike btw, yes.. I know funky gas tanks... I also included a pic of the carb i have since the internet says i have a different carburetor

 

[Bweighmaster]

Those carbs work well when clean . I reccomend using Berryman carb dip in the gallon size . Remove all plastic and rubber first .... what air filter are you running ? Stock air box helps carb to ayomize fuel . If not installled , it may not run right ......

 

[Bweighmaster]

What markings are on that carb ? Brand , model number ..?

 

[Bweighmaster]

I have a new carb in stock . TC 250 , Same basic carb .....

 

[Bweighmaster]

Any luck ?

 

[Piranahbite]

Any luck ?

oh my god, sorry man i totaly lost this site for a while, its a mikuni carb, i think a vm22? im not 100% sure i can get you an answer when i get home from work i dont have an air filter on the bike but i do have the airbox all hooked up along with the vacuum tubes, i also just got home from a camping trip and odd enough it ran almost perfectly, i think the bike floods itself after riding at like quarter throttle, i fix the issue by revving the bike till it clears up, then i continue riding till it happens, i also have the idle and throttle cable backed all the way out so it dosent run like squat, but i feel if the carb dident have its hidden issue the bike would be idleing at 2000-2500 rpm

 

[Bweighmaster]

Ok , so you're good ?

 

[Bweighmaster]

How's it going ?

 

[Piranahbite]

Uhh, no not good it still barely runs, I belive the carb is flooding itself or trying to feed more fuel than it needs, I also got a flat tire and I don't have enough time to fix it at the moment

 

[Bweighmaster]

Ok , Just checking ....

 

[troytech.2012]

I wonder if it's a matter of adjusting the float?

 

[Bweighmaster]

There is a great video on Rocky mountain ATV / MC covering float adjustment ...

 

[mightslip]

Your problem sounds like Pilot jet/Slow jet. The tiny holes are nearly impossible to clean. replace the rubber O-ring and needle as well.
You can try Berryman carb dip as Bweigh suggests but be careful to remove all rubber and the floats, that stuff is strong and any non metal part will be ruined.
My suggestion. order a jet kit ( they contain all the jets in your carburetor.) Swap them all out and as Troy suggested check your float height. Good luck.

 

[Piranahbite]

hey! I'm back! so i bought a carburetor for a 125, wrong size obviously, and i got some more info on the carb i got for you all, iv read the messages you sent and unfortunately i have a hole or three in my float, gas leaks out of it whenever i go and check it. i also have more info on the carburetor, its a vm20 on the side of the carb it says 052 20 apart from the mikuni branding that's all the info i can find on it, i measured the inside and outside diameter of the carb, and got 23mm inside diameter for the engine side and 37mm for the airbox side, im totaly open to a re build kit but have been unlucky so far in find one

Also here are some verry large pictures of my carburetor haha

 

[Piranahbite]

Amazon.com: PWK Carburetor 21 24 26 28 30 32 34mm Racing Carb Universal 2T 4T Engine Dirt Bike Motocross Motorcycle Scooter ATV Quad (24mm) : Automotive

Buy PWK Carburetor 21 24 26 28 30 32 34mm Racing Carb Universal 2T 4T Engine Dirt Bike Motocross Motorcycle Scooter ATV Quad (24mm): Carburetors - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

heres a carb i found on amazon, they have it in 24mm and 21mm, no 23mm or am i looking at the measurements wrong?

P.S. bought the 24mm it just to check if it would fit

 

[mightslip]

I f you do some looking around you can likely still find a service manual for your bike which will include part numbers etc.

 

[mightslip]

Mikuni 20mm VM Series Universal Round Slide Carburetor - VM20-273 Dirt Bike - Dennis Kirk

Find the Mikuni 20mm VM Series Universal Round Slide Carburetor - VM20-273 at Dennis Kirk. Shop our complete selection of Dirt Bike parts and accessories including the Mikuni 20mm VM Series Universal Round Slide Carburetor - VM20-273.

www.denniskirk.com

 

[mightslip]

You can try going cheap but it has been my experience they rarely work correctly.

VM20 Motorcycle Racing 20mm Carburetor For 100cc-130cc Dirt Bike Carb Universal | eBay

VM20 Motorcycle Racing Mikuni 20mm Carburetor For 100cc - 130cc Carb Universal. A carburetor is a device to mix air and fuel for internal combustion engines in the proper ratio for combustion. The fuel and air mixture is too rich if it has an excess of fuel, while too lean if there is not enough.

www.ebay.com

 

[Piranahbite]

Figured that, I just bought the one on Amazon but I do also want to know what's the proper way to measure them so I can look it up by the proper measurements I did find the part number for my carburetor and got all the information I needed out of that except for the proper measurements and diameter of the carburetor

 

[mightslip]

In the spec sheet I posted above your carb is a VM20 ( That is your barrel size )

here are 2 videos that should help you.

Kevin Cameron Explains How To Tune Carburetors