Picked up a 1985 250sx

[daves88]

Hello all. I have been an atc fan for a long time. I may have been a member on the old site about 15 years ago when I had a 200x but that has been long gone for a while now. It is nice to see how much this site has grown. After a little bit of wheeling and dealing I traded some old mini bikes for the 85 250sx you see below. Seems to be in pretty good condition with exception of the dry rotted tires and the non existent air filter. To remedy the problems I picked up a uni air filter on my lunch and also located a front tire and a set of rear tires locally on craigslist (picking them up tonight). The front is a 23x8x10 so I ordered the correct front rim and it should be here next week. So far with the tires, rim+shipping, and filter I am at $134 which is not too bad as my funds are limited at the moment. I am planning on making it a light mud/trail trike. I have always been a fan of the 250sx and it was nice to take a spin on it last night. Hopefully I will have some after photos once I get the new rubber installed. I am also hoping not to have too many issues with the front axle as I hear they can seize up?

Thanks for looking,
Bryan

228465

[Jd110]

Nice find! Looks like it was stored inside.

[UPNATM]

I'm not sure what the bikes looked like that you traded, but that's a clean SX, and I'm thinking you did pretty good on the deal. Congrats.

[Buck Snort]

Nice machine. I love my SX.

[daves88]

Yeah I think I did okay. I only had about $625 into the mini bikes and I have to believe that the sx is worth about $750? Does that sound about right?

[350for350]

If you love your sx as much as I do mine, you'll feel like it's worth $7500! They're great machines.

[jhonz]

There is one in my area listed for 2500..looks to be in about the same shape as yours. .I see them in my area for around 2000 up. . I'd say you did very well. .awesome find.

Sent from my SM-G928V using Tapatalk

[dustrunner]

good deal for you , the sx will go everywhere a mini bike dreams about going .

[daves88]

I did the tires and new front rim last weekend. The axle came out with no issues and the swap was simple. The front brake pad did come off one of the shoes however. I have a package waiting for me. It is either new shoes or the carb kit I ordered.

The new issue that I am now having is that it will run for a while and then just cut out and stop and I have to sit there for a few before I can get it started back up. I thought I was losing spark but when it happens I pulled the plug wire and it still gives me a pretty good shock. After I sit for awhile it starts back up like nothing has happened. I am now leaning towards it not getting fuel (hence the carb kit). I think I also need to check the petcock to make sure there are no issues with it as well. Has anyone here experienced anything similar? When I put it away Saturday it happened again to the point that my battery died before she would fired back up. I am hoping it will be an easy fix as I am not one for projects. I have taken too many things apart and never put them back together. I will have to find the carb rebuild thread. I think I saw one not too long ago.

Anyway here are updated pics, I think it looks much better and I prefer this set up as far as handling goes.

229216229217

[daves88]

Also, where is a good place to look for or post up a want to buy thread? I was wanting to look into a rear rack and also a hitch. Is there a classifieds section here? If so can you only see it if you have a certain amount of posts?

[wonderboy]

With regard to your stalling issue: I agree it seems to be fuel related. The petcock on that machine has a small bowl with a screen. Unscrew the bowl and check for crud. Of course, make sure you have good clean gas in there. Other than that, a carb disassembly is probably needed. The key is to not just pull it apart and throw the new parts in. You really need to clean all the passageways and make sure all the openings that need to open are clear. Compressed air and carb cleaner are the minimum needed.

With regard to the rear rack: my advice is that if your fenders are not currently drilled for a rear rack, then skip this. The rear rack system for the 250SX (the factory one anyway) requires two holes be drilled through your fenders for a couple of the mounting points. The rear fenders on that machine are not too easy to find in good condition. I'd be hesitant to put holes in it. Of course, if that is really important to you go for it. But if you do, you actually may be able to sell your good solid set for way more money than a set that has the holes in them. So maybe you can come out ahead on the deal. Just my opinion...

Agree with everything above though, the SX is an awesome machine.

[UPNATM]

The new issue that I am now having is that it will run for a while and then just cut out and stop and I have to sit there for a few before I can get it started back up.

I just had the same exact issue with one of my SX's. I initially thought it was a carb issue also, but since the carb on it was a fresh rebuild courtesy of Jim (flyingw) if was able to rule that out. I soon found that it was my CDI, and confirmed that by pulling a known good one from my other SX. I was able to find a used one, here on the forum, and once replaced, ran like a champ again.

[UPNATM]

Also, where is a good place to look for or post up a want to buy thread? I was wanting to look into a rear rack and also a hitch. Is there a classifieds section here? If so can you only see it if you have a certain amount of posts?

Unfortunately, you don't have enough posts, or time here on the forum to access the classified section. My advice to you would be just what you did, post what your looking for here in your thread. You seem to be getting a pretty fair amount of traffic here. :p

[daves88]

With regard to your stalling issue: I agree it seems to be fuel related. The petcock on that machine has a small bowl with a screen. Unscrew the bowl and check for crud. Of course, make sure you have good clean gas in there. Other than that, a carb disassembly is probably needed. The key is to not just pull it apart and throw the new parts in. You really need to clean all the passageways and make sure all the openings that need to open are clear. Compressed air and carb cleaner are the minimum needed.

With regard to the rear rack: my advice is that if your fenders are not currently drilled for a rear rack, then skip this. The rear rack system for the 250SX (the factory one anyway) requires two holes be drilled through your fenders for a couple of the mounting points. The rear fenders on that machine are not too easy to find in good condition. I'd be hesitant to put holes in it. Of course, if that is really important to you go for it. But if you do, you actually may be able to sell your good solid set for way more money than a set that has the holes in them. So maybe you can come out ahead on the deal. Just my opinion...

Agree with everything above though, the SX is an awesome machine.

I will check the bowl/screen. Even if that is the culprit I still want to run through the carb as it has a bit of a hesitation at certain rpms. I am not the best with carbs but my buddy can give me a hand if needed and he also has a compressor and that is currently where I am storing it (he also butts up to a gravel pit :p).

I would rather not put holes in my plastics. Maybe I will settle for a six pack rack down the road, or fab up something small.


I just had the same exact issue with one of my SX's. I initially thought it was a carb issue also, but since the carb on it was a fresh rebuild courtesy of Jim (flyingw) if was able to rule that out. I soon found that it was my CDI, and confirmed that by pulling a known good one from my other SX. I was able to find a used one, here on the forum, and once replaced, ran like a champ again.

That was my initial thought as well but when it happens I pull the plug wire right away and always receive shocks. Is there a way to test it without having a spare on hand? Also with a quick ebay search I see that there are new one listed for under $35 but they state that they are only compatible with 86-87 model years. Is the cdi for the 85 different?

I appreciate both of you helping me out. I usually try to research the issues I am having but sometimes it's tough setting aside the time or to find solid information.

[Hurley250R]

Could it be as simple as the on/off gas cap vent being clogged? After you stall it try opening the the cap to allow air in and see if it starts.

[daves88]

Unfortunately, you don't have enough posts, or time here on the forum to access the classified section. My advice to you would be just what you did, post what your looking for here in your thread. You seem to be getting a pretty fair amount of traffic here. :p

That's what I figured. Do you know how many posts are needed? I read the rules but didn't see it listed, or maybe I missed it. Never mind, found what I needed.



Could it be as simple as the on/off gas cap vent being clogged? After you stall it try opening the the cap to allow air in and see if it starts.

I did open the cap once and it made a pretty loud suction noise. I have also heard similar but less noticeable bubbling/slow suction noises around the gas tank. Thank you for the tip I will check that out today as well.

[Chopsaw]

sounds like it was the cap then . My 85 was runnin the bowl dry too. One thing that gets over looked is the pick up screen in the tank that controls the reserve level . Mine was blocked . Like I said , yours sounds like its the cap .

[daves88]

Can the caps be fixed or are they usually easier to just replace?

[Hurley250R]

I think they can be fixed. Should be how to videos on youtube

[daves88]

I think they can be fixed. Should be how to videos on youtube

Found a couple vids, Thanks!

[UPNATM]

Is there a way to test it without having a spare on hand? Also with a quick ebay search I see that there are new one listed for under $35 but they state that they are only compatible with 86-87 model years. Is the cdi for the 85 different?




http://farm6.static.flickr.com/5136/5466688368_77491c7ef2_b.jpg
http://farm6.static.flickr.com/5216/5466091295_11be77e11b_b.jpg off the http://www.3wheelerworld.com/showthread.php/126168-ATC250-(es-sx)-amp-TRX250-Service-Data


Yes, if I remember right, the difference is that and 85 only has one connector vs the 86/87 that has two. They for sure carry different part numbers.

[daves88]

It started right up today. I let it warm up and then ripped around until I got it to cut out and stall. Cracked open the gas cap and then it started right up. Ripped it around until I got it to cut out and stall a second time, but this time I tried to start it before cracking the gas cap but had no luck. I took the gas cap apart and the inside was clean. I didn't see anything that would lead me to believe it was the culprit. I then managed to lose a small rubber grommet so I put it together without it. I ripped it around for a few and it never cut out. I ran some wheelies to make sure it didn't leak without the grommet and so far all seems to be well. Maybe that little rubber piece wasn't really needed. I will need some more ride time on it to be certain that it doesn't happen again.

Tomorrow I will be doing the front brakes. I am also thinking about looking into adjusting the valves? I assume it would be a good idea seeing that it is 30 years old.

[daves88]

Yes, if I remember right, the difference is that and 85 only has one connector vs the 86/87 that has two. They for sure carry different part numbers.

Good info there. Thank you for sharing, I will have to keep it mind.

[BigRedGrizzly]

http://uploads.tapatalk-cdn.com/20160319/b229783879fbdaf12354de56013f9897.jpg
Check out this guy on Facebook. He recently posted a picture of a bunch of parts and parts machines in the back of his pick up truck. I thought I saw a rack in there.
Good luck.

[Chopsaw]

You need the seal . Clean the vent hole in the cap . Search thru old threads on here .

[BigRedGrizzly]

http://uploads.tapatalk-cdn.com/20160319/8907252db2a5a6f9e448cda043a4f0ad.jpg

[daves88]

I saw his listing the other day. Someone already inquired about the racks and he stated they were sold. Thanks for the lead though.

[ArizonaATC]

Looks mint!

[UPNATM]

So, i'm curious. What's the final verdict? Tank not breathing, carb, ??

[SamT]

My 250es had a frayed wire that would hit a bare spot on the frame now and then and kill it. It only happened now and then, until I went for a swim in about 2' of water with a little salt in it and that sucker would die every time you splashed water.

[daves88]

So, i'm curious. What's the final verdict? Tank not breathing, carb, ??

I took the gas cap apart and it hasn't done it since. I went ahead and rebuilt the carb anyway though. Gonna have to make some adjustments still.