Carb rebuild 93 Honda 300 Fourtrax.

[F250 guy 106]

Just ordered the Shindy kit, is there any sticky articles with photos to refer to when I do the rebuild, cause my new kit comes with a new screw for the idle knob. 

 

Thanks. 

 

JD

[Wheeler 2,468]

I’m sure someone may have a few photos. Just take ur time & clean everything spotless. Compressed air will be your friend. If u have any issues lots of us including me can help u out. 

Edited January 12, 2020 by Wheeler

[F250 guy 106]

45 minutes ago, Wheeler said:

I’m sure someone may have a few photos. Just take ur time & clean everything spotless. Compressed air will be your friend. If u have any issues lots of us including me can help u out. 

Would sonoco optima 95 octane be ok to run on stock jets? That's all that's in my area for Non Ethanol without 93 octane marina fuel.  Thanks man.

[retro 3,871]

The service manual is your best resource while refreshing a carb. Follow the disassembly/assembly steps and setup instructions word for word 'til ya reach the end of the chapter. There are photos showing all of the parts locations and the order they must be assembled. Also, 95 octane fuel will not effect the jetting or the way the motor runs. Octane is a rating for fuel stability, aka resistance to detonation. Keep us in the loop as you work on that carb if ya can.

[F250 guy 106]

21 minutes ago, retro said:

The service manual is your best resource while refreshing a carb. Follow the disassembly/assembly steps and setup instructions word for word 'til ya reach the end of the chapter. There are photos showing all of the parts locations and the order they must be assembled. Also, 95 octane fuel will not effect the jetting or the way the motor runs. Octane is a rating for fuel stability, aka resistance to detonation. Keep us in the loop as you work on that carb if ya can.

I can't get the link to the manual for a 93 2WD 300, I use a phone with unlimited data. No internet at my mom's as of last week.

Edited January 12, 2020 by F250 guy

[retro 3,871]

@F250 guy, hows about I post the service manual pages here for ya? I'll try to email a copy to you as well... go ahead and edit out your email from your post so ya won't get spammed...

[F250 guy 106]

6 minutes ago, retro said:

@F250 guy, hows about I post the service manual pages here for ya? I'll try to email a copy to you as well... go ahead and edit out your email from your post so ya won't get spammed...

K thanks

[retro 3,871]

I emailed ya chapter 4 of the FSM @F250 guy, that same PDF file is attached here. The entire Service manual PDF was too big for the mail server (52.7 MB), so I just broke out the fuel system section. I will separate those 15 pages into individual images in the next post(s).

88-94-TRX300-Fuel-System.pdf

[retro 3,871]

Section 4, pages 0-5

 

 

 

 

 

 

[retro 3,871]

Section 4, pages 6-10

 

 

 

 

 

[retro 3,871]

Section 4, pages 11-15

 

 

 

 

 

 

I tried to clean up that 1st batch of images. Hope this works OK for ya, if not hollar.

[Goober 1,555]

Here’s a pic

this is a pic of an unrebuilt carb—see how clean the exterior is before disassembly?

 

Before disassembly i spray the body and all screws with deep creep—removing dirt with a plumbers flux brush. Then i wash it down with dawn dishsoap. This gets large particles off the exterior 

 

i disassemble with the best cross point i have—a large handled nut driver with a #2 bit. And make sure to hit the jets with deep creep too. Use the best fitting straight bit screw stick you have and gradually apply torque—I’ve had jets break on me. Use a 7 or 8? mm socket on the main jet.

 

see my pic? I use dental brushes, flux brushes, brass brushes and bamboo-handled cotton swabs. I use the broken handles of used swabs to scrape out bits of gasket. 
 

be careful with the bowl and carb body—there’s a priming channel built into it—leading to a tiny brass jet in the carb throat If you soak it you might clog it. If i soak my carbs, it is because they are clean and only in clean fluid. Lotta owners don’t care about the priming feature but i do

Edited January 12, 2020 by Goober

[toodeep 1,732]

If the machine has sat for a length of time plan on soaking it in a carb cleaner. I have an ultrasonic cleaner I use for them but I deal with a lot of them. Some think if a little stabilizer is good a lot is better.  It makes me money. lol

[Fishfiles 19,706]

250guy , are you finding what you were looking for , looks like your in good hands 

[F250 guy 106]

I am, the thing I'm not seeing and reviewing the manual photos n steps (thanks retro and goober) is the screw for the idle speed knob, my new kit will have a new one, my question is how many threads is it screwed in or will I just have to take a photo with my phone and zoom in? 

[Fishfiles 19,706]

if you are really worried about the idler bolt  , measure the exposed thread with a ruler , you are most likely going to have to readjust the idle , and when you screw the new bolt in , just screw it in till it makes contact then adjust it once you start up 

[F250 guy 106]

I was gonna measure anyway lol, mine is slightly warped from the PO pulling when he adjusted it. Thanks man

[toodeep 1,732]

I wouldn't even worry about replacing it unless the old one was bent. With that said just screw it in until the butterfly on the throttle shafts starts to open. You can adjust it from there once it's running.

[retro 3,871]

I screw the idle speed screw in until the butterfly cracks open equal to the diameter (the inner edge of the butterfly open to match the back edge of the idle mixture port) of the idle mixture port. Or open about .012" in your case. Once the motor is warmed up you will fine tune the idle mixture screw and idle speed screws, settling at 1450-1500 RPMs idle speed. @Goober might have a pic showing what I mean.

[F250 guy 106]

I'll just leave it in there and find a tach. 😁

[toodeep 1,732]

No need for a tach on a 300. Start with the pilot screw (air mixture) at about 2 1/2 turns out and set the idle to where it sounds good and still shifts good while idling. The pilot screw will need to be adjusted to your elevation and machine but usually around that 2 1/2 is a good starting point. 

[F250 guy 106]

18 minutes ago, toodeep said:

No need for a tach on a 300. Start with the pilot screw (air mixture) at about 2 1/2 turns out and set the idle to where it sounds good and still shifts good while idling. The pilot screw will need to be adjusted to your elevation and machine but usually around that 2 1/2 is a good starting point. 

I thought RPM had to be spot on sorry brain fart there. 

[retro 3,871]

As long as idle RPM is below clutch engagement, you're golden.

[Goober 1,555]

Here’s a pic of the idle screw side.

when I install a trx300 carb which BTW is super easy:

as too deep said turn pilot screw 2 to 2.5 turns out. I install Idle screw where it’s just touching barely the throttle. Hold your carb up to a light while the butterfly valve is closed—you want minimum light (valve opening) small as possible 
screw in the carb side cable adjustment—and then engage the cable to the throttle link so you’re not twisting the cable. Set you handlebar cable adjustment and the carb side adjustment each to a halfway position if you can and take up all the slack in the cable. You want the linkage to instantly respond to your thumb throttle input

[F250 guy 106]

2 hours ago, Goober said:

Here’s a pic of the idle screw side.

when I install a trx300 carb which BTW is super easy:

as too deep said turn pilot screw 2 to 2.5 turns out. I install Idle screw where it’s just touching barely the throttle. Hold your carb up to a light while the butterfly valve is closed—you want minimum light (valve opening) small as possible 
screw in the carb side cable adjustment—and then engage the cable to the throttle link so you’re not twisting the cable. Set you handlebar cable adjustment and the carb side adjustment each to a halfway position if you can and take up all the slack in the cable. You want the linkage to instantly respond to your thumb throttle input

That helps out slot, thanks a bunch man. And will do on the adjustment still waiting on my Shindy kit, shipped the 11th. Arriving on the 16th one day before my 29th birthday or on the 22nd.