I have been having issues with my MT 250 original carb, I have cleaned, replaced parts and made numerous adjustments to no avail. Tried 3 aftermarket carbs with less than desirable results, changed jets up and down. The primary issue with the stock carb is it just lets too much gas in, I have changed jets out. with mirror angled it looks like gas coming up thru needle housing, changed needle several time, oh and I had adjusted the float more time than I can remember, even testing the float off the bike with working results. I like your replacement but way to expensive.
What do you mean too much gas? Are you getting runaway throttle? Also look at your air mixture screw. The original was solid but the replacement one has a hole.
What happened with the mt 250 Never seen nothing else about how it's running now... Well good luck At getting running right. Thats a fun Trail bike to ride fast to.......
I'm interested to see it running fine as well. I just got MT125 a couple of months ago. It has the same carb, but it's 24mm. I'm still in the process of cleaning it and I think it has missing small air jet on the back.
Not sure I mentioned it but I use 58 pilot. A 115 main and needle second from the top .. when I did that and sanded the head flat it was like a brand new engine I couldn't believe how good it ran almost like a cr 250 My brother said it feels like a brand new engine I used a old wiseco with The l shaped top ring
Hi there glad to see you working on the mt 250 again.. my personal opinion is it is not the carb? Not sure You would like to hear that. But I'm almost sure it's one of two things It's got a head leak.. Wondering if you used original or copper the copper Will bring up the compression and I always aneal it first and spray with Copper spray works great I've never had a leak if I use that stuff on both The oem and copper gasket.. but I think and I've had a lot of experience with the mt is your timing is off.. if you use a volt meter it should read all the time but when it Gets to the fire mark the and the points just crack you will see a stumble in the volt meter I use a sound box it hume's all the time but when the points crack at fire mark it Changes pitch a little higher and kicks over usually first kick. There is one more thing I was concerned over Is your pipe cleaned and not clogged sometimes you have to burn them out it has fiberglass in lay that can be clogged with carbon. But I'm sure you've started with out the pipe hook up that can tell you alot if it revs out good with out the pipe it's clogged Any way have a great day..
Hey Sage! Thanks for watching. I actually used copper coated gaskets (episode 12) and I did a air leak test with it running using starter spray on the head, intake and carb seals. No change in idle. I will re-check the timing to confirm. 👍
@@CurtisTarwater the starter spray Will work on the carb intake but not on the head of that type engine it will just push it away because of high compression I know I did the same thing. I was having a hell of a time . wondering wy it didn't run right Then I did it I took the head off taped Some 280 grit to a glass pitcher frame did a up and down motion About ten times and then I seen it High and lows every where continue ed to go . I took a screw driver and Held the pitcher frame over the garbage can and taped it off every 15 back and forth motions very important you only go in one direction not circles when I was done I was surprised how good it looked like it was milled on a machine. ... Those magnesium heads are almost always Warped With strayations through out it The aluminum one can take more heat then the magnisum ones you can't let that engine over heat but 90 percent of people did but I seen when you were hiting the throttle it was just stalling... i now it sucks to take it apart but back tracking and some tricks of the trade can fix it I guarantee it? But one quick thing to check and get out of the way is take the exhaust pipe off it will be loud start it up if it revs out to high r.p.ms you now the exhaust is clogged .
That's the $64K questions. Some are out there on eBay and other people find a 36MM off a CR250 Elsinore and swap it on. Good luck on trying to find your setup!
I have been having issues with my MT 250 original carb, I have cleaned, replaced parts and made numerous adjustments to no avail. Tried 3 aftermarket carbs with less than desirable results, changed jets up and down. The primary issue with the stock carb is it just lets too much gas in, I have changed jets out. with mirror angled it looks like gas coming up thru needle housing, changed needle several time, oh and I had adjusted the float more time than I can remember, even testing the float off the bike with working results. I like your replacement but way to expensive.
What do you mean too much gas? Are you getting runaway throttle?
Also look at your air mixture screw. The original was solid but the replacement one has a hole.
Look at this thread on the air mix screw -
www.thumpertalk.com/forums/topic/1377641-74-honda-mt-250-basic-carb-settings/
I think you would've been better off using the nos carb & make sure it is tuned spot on !
What happened with the mt 250
Never seen nothing else about how it's running now... Well good luck
At getting running right. Thats a fun
Trail bike to ride fast to.......
Hey Sage! Sorry for the delay. Had another project interrupt my progress - son's car. I'll have another video out shortly.
I'm interested to see it running fine as well.
I just got MT125 a couple of months ago. It has the same carb, but it's 24mm. I'm still in the process of cleaning it and I think it has missing small air jet on the back.
Not sure I mentioned it but I use 58 pilot. A 115 main and needle second from the top .. when I did that and sanded the head flat it was like a brand new engine I couldn't believe how good it ran almost like a cr 250
My brother said it feels like a brand new engine I used a old wiseco with
The l shaped top ring
Hi there glad to see you working on the mt 250 again.. my personal opinion is it is not the carb? Not sure
You would like to hear that. But I'm almost sure it's one of two things
It's got a head leak.. Wondering if you used original or copper the copper
Will bring up the compression and I always aneal it first and spray with
Copper spray works great I've never had a leak if I use that stuff on both
The oem and copper gasket.. but
I think and I've had a lot of experience with the mt is your timing is off.. if you use a volt meter it should read all the time but when it
Gets to the fire mark the and the points just crack you will see a stumble in the volt meter I use a sound box it hume's all the time but when the points crack at fire mark it
Changes pitch a little higher and kicks over usually first kick. There is one more thing I was concerned over
Is your pipe cleaned and not clogged sometimes you have to burn them out it has fiberglass in lay that can be clogged with carbon. But I'm sure you've started with out the pipe hook up that can tell you alot if it revs out good with out the pipe it's clogged
Any way have a great day..
Hey Sage! Thanks for watching. I actually used copper coated gaskets (episode 12) and I did a air leak test with it running using starter spray on the head, intake and carb seals. No change in idle. I will re-check the timing to confirm. 👍
@@CurtisTarwater the starter spray
Will work on the carb intake but not on the head of that type engine it will just push it away because of high compression I know I did the same thing. I was having a hell of a time
. wondering wy it didn't run right
Then I did it I took the head off taped
Some 280 grit to a glass pitcher frame did a up and down motion
About ten times and then I seen it
High and lows every where continue ed to go . I took a screw driver and
Held the pitcher frame over the garbage can and taped it off every
15 back and forth motions very important you only go in one direction not circles when I was done I was surprised how good it looked like it was milled on a machine. ... Those magnesium heads are almost always Warped
With strayations through out it
The aluminum one can take more heat then the magnisum ones you can't let that engine over heat but 90 percent of people did but I seen when you were hiting the throttle it was just stalling... i now it sucks to take it apart but back tracking and some tricks of the trade can fix it
I guarantee it? But one quick thing to check and get out of the way is take the exhaust pipe off it will be loud start it up if it revs out to high r.p.ms you now the exhaust is clogged .
Where can I find a carburetor
That's the $64K questions. Some are out there on eBay and other people find a 36MM off a CR250 Elsinore and swap it on. Good luck on trying to find your setup!