Honda 250SX & ES Carbs the Same?

[zainyD]

I have an 85 Honda 250 SX that I'm trying to get road worthy again. One of the things I need is a replacement carb. I am currently bidding on a used one on Ebay and also trying to get in touch with a forum member here who posted one for sale a couple weeks back. My question is whether the carbs used on 250 SX and ES bikes of the same year are the interchangeable. If they are that would simplify my search and enable me to find a replacement more easily. I noticed the carb rebuild kits work for both models and externally they look identical.

[rdlsz24]

Yeah they are the same. I used a 250sx carb on my 85 Big Red and it worked fine

Rob

[zainyD]

Great, thanks. That will make finding a replacement a LOT easier.

[badass350x]

Yep there the same, just clean it up real well before you put it on! I think Fabiodriven can help you out with that part!!!! He's a pro at them,,,,, JUST KIDDING FABIO!!!!!

[userj8670]

If you get the carb from '85 you will have cold starting problems. If however you dont have access to the ultra rare cold start kit, simply drill your starter jet one size bigger and it will solve your problems. I have done this with great luck!

[tri again]

x2 w/ 8670 usually the Keihin QA01 had the cold start issue.
I fought one for over a year until I just reamed out the cold start jet.

1/2 kick starts in any weather now.

Used carb?
The BIG issue is the choke enrichment piston and choke cable.
It would be best if they all came together and worked.
Those pistons can get terminally stuck.

I got an sx with an aftermarket Keihin with the old fashioned
flip flapper choke and it has an accel pump which squirts gas when you hit the throttle.
Kinda acts like a choke in that sense too.

I can get the number off it if you want that option.

[dougspcs]

If you get the carb from '85 you will have cold starting problems. If however you dont have access to the ultra rare cold start kit, simply drill your starter jet one size bigger and it will solve your problems. I have done this with great luck!

I would be interested in knowing the size to drill the jet too for this modification myself. Anyone know the drill size??

[zainyD]

Good tips guys. I'll print out that service bulletin. I'm really impatient to get my trike going again, but the Ebay auction for the carburator still has six days left. It'll probably be a couple weeks before I have all the parts and get it put together.

[userj8670]

I cant remember off the top of my head but take your drill index and find the drill that fits the current jet. then just go up one size. All your doing is boring it out...like a cylinder :)

[ahardwick]

What jet is the starter jet? Can somebody post a pic?

[ahardwick]

Zainy, I have an 85 250 es carb. It does not have the choke cable or piston. I upgraded to an 86 carb because of cold weather start issues.

[just ben]

If you get the carb from '85 you will have cold starting problems. If however you dont have access to the ultra rare cold start kit, simply drill your starter jet one size bigger and it will solve your problems. I have done this with great luck!why not just spend a couple bucks on a new jet?

[Thorpe]

drill size is .080"

[Frankencelery]

Interesting stuff, guys. I've got an '85 and inexplicably it started having hard starting two winters ago. Is this something that deteriorates over time? I'd be happy to drill out the starter jet, but I can't help but wonder why it didn't do this before.

[zainyD]

Zainy, I have an 85 250 es carb. It does not have the choke cable or piston. I upgraded to an 86 carb because of cold weather start issues.

I'm interested! I'll send you a PM and see what we can work out.

[Dirtcrasher]

I posted it ages ago, I believe it was .080 thousandths (as well as Thorpe said) I do not recall the drill # but it's chicken to locate with google.

I also believe it's a QA03 that stinks, QA08 is the 86/87 carb. QA05 might be the 350X which also starts fine but I cannot confirm this. I don't do much wrenching lately.......

Blow the chips out backwards with carb cleaner after and grease your drill bit when drilling.

[zainyD]

Should be a 5/64" bit.

[dougspcs]

I posted it ages ago, I believe it was .080 thousandths (as well as Thorpe said) I do not recall the drill # but it's chicken to locate with google.

I also believe it's a QA03 that stinks, QA08 is the 86/87 carb. QA05 might be the 350X which also starts fine but I cannot confirm this. I don't do much wrenching lately.......

Blow the chips out backwards with carb cleaner after and grease your drill bit when drilling.

Awesome thanks DC, Thorpe and others for input..I'll do that in the next weekend or two. I'd love to make the 85s cold weather ready!

[tri again]

Interesting stuff, guys. I've got an '85 and inexplicably it started having hard starting two winters ago. Is this something that deteriorates over time? I'd be happy to drill out the starter jet, but I can't help but wonder why it didn't do this before.

May not be it but I cleared 90 carbs with a .005" acupuncture needles before I discovered an .080 guitar string will fit.
An then .010"
It's some sort of plaque like the dentist scrapes off yer teeth with that steel lever
or ultrasound.
jackhammer.

Your 85?
sx br?
could just be that the choke enrichment piston isn't throwing all the way.
Stretched choke cable?
Last valve adjust was how long?

Some say slosh the trike side to side violently before you start it.
I've also noticed (and posted) why does mine spin great and fast with the starter
but not really want to start but by foot cranking it to compression stroke, it fires immediately.

I really don't mind the quirks.
Unauthorized personnel can't get them started. ;-)

[tri again]

Good tips guys. I'll print out that service bulletin. I'm really impatient to get my trike going again, but the Ebay auction for the carburator still has six days left. It'll probably be a couple weeks before I have all the parts and get it put together.

That service bulletin is only good to let you know you are not crazy and not the only one.
The parts are hard to find.
The jet also may not want to come out but by trying with the screw, mine reamed itself enough to be perfect.
I would totally bite to break the carb casting so I just quit.
..and then it works, starts perfectly because of the mild mutilation of the brass cold start jet.