Vintage Dirt Bike Q & A

my 125 tail light is 3 bolt I'll head the headlight assembly next time I go out

what's the diameter of the MT250 kick start? I need one for my 125, but noone on ebay is responding

Its about 17mm you could probably also check the seals on bikebandit if they have the same part number the shaft is most likley the same. I would think the 125 shaft would be smaller but maybe not.

Yes, I think both the 3 and 4-bolt taillight assemblies are interchangeable between the MT125 and MT250.



The MT250 bracket appears to be unique to that bike, but perhaps the 125's can be made to work. I believe the MT125 and MT250 headlights are interchangeable, and the brackets look similar except for the reflector mounts on the 250 unit. It would be hard to be sure without seeing them both side by side.

Ray

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'74 CR125M (175cc), '75 MR175, '82 RM250Z, '08 YZ250F, '14 Zero FX electric, '14 Zero MX electric, '18 Alta MXR electric

there's a MT250 in belleville for $180 ... it was WAY too rusty for me to buy as I wanted something I could repair, but it has a LOT of parts including all the front lights and tail light. look at my pic and see the rust on my chrome, that was the level of rust on his chrome

if you do think about buying it, let me know as I could use a few parts off it, but he didnt want to part it out

seals? no I want the kick pedal

I know the shaft the kick pedal goes on goes thru a seal and if its the same on both bikes its the same size shaft and that means that the mt250 kick pedal would fit the shaft.

yeah some guy on ebay finally replied and said the hole is like 15mm. the shaft is a hair bigger so it'll fit perfect

here's my rear fender patch

got a bunch of parts in today, but the biggest dissapointment was the 1975 MT125 carb I bought is different output diameter and throttle barrel diameter than my engine/carburetor... so now on out over $100 on carbs that sit in a pile I have to resell...

Good news is I got the starter lever and generator cover. and the throttle cable is in the mail.

if anyone has a lead on throttle adjustment parts or that little steel plate in the carb, LET ME KNOW ASAP!

I don't know if this is the carb you bought, but I'm 99% sure this one is the correct 24mm carb for all three years of MT125:

http://cgi.ebay.com/ebaymotors/1975-Hon ... ccessories

If your 'new' carb looks like this one and the motor end has an inside diameter of exactly 1", it's almost certainly the correct carb, which means the one that was on the bike is probably not original.

Ray

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'74 CR125M (175cc), '75 MR175, '82 RM250Z, '08 YZ250F, '14 Zero FX electric, '14 Zero MX electric, '18 Alta MXR electric

that is the one I bought, I'll have to measure it to see if I have a possible claim

the one that came on it was 29mm could this be from a MT 250? the guy I bought it from was under the impression it was a 250 (not very bright)

so to use this carb I just need the correct rubber adapter thing?

Does the carb that's on it look like this one? Sorry, this is the least crappy picture I could find.

http://cgi.ebay.com/ebaymotors/HONDA-MT ... ccessories

If so, this is the same carb I have on my MR175, and it was also used on the early CR125's. It's actually a pretty good carb when it's working right. I assume there's some reason you're replacing your carb, so you may want to keep the one you just bought. I don't think you really have a claim for returning it, since it's the correct one for your bike.

It looks like you may have a CR125 intake manifold on your bike, but I can't really tell from the picture. If so, you'll need an MT125 manifold to use the MT125 carb, unless you want to wrap the motor end of the MT carb with tape, which I wouldn't recommend.

Ray

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'74 CR125M (175cc), '75 MR175, '82 RM250Z, '08 YZ250F, '14 Zero FX electric, '14 Zero MX electric, '18 Alta MXR electric

sounds like I'm buying a manifold and selling off this carb

the only reason I need to replace it is because the throttle is missing

danm carb is siezed shut, the screws wont come out so I spaked it in pb blaster and heted it with a trch then more pb blaster then more torch and now it's in the freezer.... then Ill hit it with the torch and more pb blaster...

if that dont work.... I guess I have t some how drill a steel screw out of an aluminum hole.... how the hell do I do that?

I might be able to cut and grind off the heads with a dremel and maybe reuse the bottom from the wrong carb??? they seem the same... but I havent seen the internals yet of the correct carb

One more question, when I added the kick lever and turned the engine over the lever didnt return... is there a spring for that and where would it be located? I have a kick internals from a XL185S so I might be able to swipe a spring and make it work