How to Clean a 4 Stroke Carb Part 1

How to clean a carb on a 4 stroke MX bike.

Category:

Sports

Tags:

• Forshee Motorsports
• carb cleaning
• motocross
• MX

[sabhacker101]

how do you do this on a two stroke bike ?

[ForsheeMS]

@sabhacker101 A 2 stroke carb is a lot like a 4 stroke carb only easier. You still have a pilot jet and main jet that need to be cleaned. The float and inlet needle are just like a 4 stroke carb. A 2 stroke does not have an accelerator pump and the slide is only 1 piece so you don't have the vacuum plate to deal with.

[gagefixer]

i have a question2008 crf 150r has a slight bog if you open the throttle slightly quick . slow and smooth the response is fine . any suggestions ?

thanks in advance

pete

[ForsheeMS]

@gagefixer Generally the CRF150R was jetted too lean from the factory. It needs a 45 pilot jet providing everything is all stock. Give that a try and your bog should go away.

[andytaggart]

Hey mate, great video. My Piaggio 125 was giving me trouble and it turned out the carb was dirty. The mechanic charged me for 2 hours work. Would you say that was fair enough?



[reaperisgrim]

hi, thanks for making this video, i have a question maybe you can help me out. the carburator on my 03 wr250f has a fuel screw that is on the outside of the bowl, it is made so that you can grab it with your fingers and adjust without removing the bowl. with that being said, i cleaned the carb just like the video put it all back together and it would fire right up with choke on, with choke off would not run with the fuel screw 1 3/4 out it will not run.

[reaperisgrim]

turn it about 4 turns out and it runs but idle is hard to get leveled out, Also the fuel screw gets real loose allowing motor vibrations to cause it to turn, could my pilot jet be (re)stopped up, do you think the tiny o-ring might have fallen out on me during reassembly? the only other thing i had trouble with was the seal on the valve vacuum control, it kept wanting to swell and not stay in place. any suggestions on parts i may need to order before i rip it apart again would help lots, thanks.

[Stoikko]

Also my friend is telling me not to mess with the jets or float bowl because when removing the jets they have to be screwed in a certain amount of turns to tune the carb is this true ?

[Stoikko]

Hey man thanks you so much for the quick response I really appreciate it. One more question on the bottom of my carb should I take the float bowl out to clean my jets and replace them. Or can I just take that bolt out of the bottom to get the job done?

[ncjerkin]

I also live in new york so its currently middle of winter. so this could be the reason for my bike running leaner then usual. but have the new exhaust might make my bike run somewhat richer. just thought i would tell you because when spring comes around my carb will probably have to be re-jetted.

[ncjerkin]

hey i have a yz 125 and when i go to wide open throttle the sound of my exhaust is not smooth as it should be. reving to 1/8 up to 1\2 throttle my bike pings and is crispy. i just added a FMF gold series header and vforce3 valve. i understand the main jet controls 1/2 throttle to WOT. while reving the bike out it sounds very raspy like a roooohhhhhaaaaa sound. perfect example is someone trying to scream at the top of there lungs but there voive cracks and is raspy. please give me some advise!

[brentspatriots]

Hey ForsheeMS, I have a 2010 YZ250F, I filled the tank and added stabilizer for the winter, its been sitting 3 months not being used, just noticed a pool of fuel below the bike. Its leaking from the vent lines. Any idea why this might be happening? I did leave the fuel valve open and closed it after i noticed the pool of gas. Ive now pulled off the carb and am attempting to clean it with the help of your vid.

[brentspatriots]

@grudgingleader i have the same problem, this happened after a mechanic installed an after market carbscrew on the bottom of the carb. Its adjustable. I dont know how it works but it just gives it more fuel. and therefor after i let off the throttle it it keeps the rpms higher for a bit burning off excess fuel. What is this exactly ForsheeMS?

[2403328]

Good video, but not very clear. A Go pro would be a really good investment for you. You can use it for riding, and for better quality videos.