How durable are 85-87 250SX's?

[EvilMooseofDoom]

I just picked up a pair of 1985 ATC 250SX trikes....one with a broken ring gear. How durable are these bikes? How does one break the rear end in one of these things? Should I build one of them up, or just part out the entire mess? Currently, I have enough parts to build 1 3/4 bikes, the rearend is missing the ring gear on one of them....

Is there some source for new gears?

in addition, just how "sporty" are these things? Are they somewhat maneuverable, or are they just as big of a tank as the same-year 250 big red?

[Tri-ZNate]

definatly more manuverable than the Big reds and have the ability to go 55-57mph stock. I MXed mine last year at TF and i weight 280lb so yeah i'd say they are durable :D. There should be a few guys to chime in on how to break it apart, I've never had to rip into the rear.

[chris200x]

I've managed to sink mine a few times in water and everytime it fired right back up.

Routine maintenece is key (as it should be with any bike) But these motors are indesructable. The rear end and diffrential can be bought on ebay. They are quite plentiful but can easily sell for over $100. I believe the big red and TRX rears are the same as well. It's kind of a pain in the rear to get the rearend apart but a good manual and a few quick questions on the forum here you should have no problems.

This is the second SX I've owned over the years and it's by far the most comfortablist, realible trike going. Electric start and reverse really come in handy and they can pretty much go through anything. I escpecially like super low first gear. I hardly use my brakes going down hills. Just an all around fun machine to own.

[EvilMooseofDoom]

okay....a couple of other questions then....

1. Where can I find a magneto/ignitor/stator assembly? Supposedly, with both bikes, both had the same ignition problem....

2. Who makes aftermarket exhaust for it? Which one is the best? Loudest?

3. Are the carbs 'rejettable'...so you can rejet for the pipe mentioned in question #2?

4. If one train is traveling from chicago to los angeles, and another train traveling from los angeles to chicago, with both trains traveling 70 mph, both leaving at exactly the same time, when will both trains strike a car parked in Brazil?

5. How do these bikes compare, power-wise, to a 1997-2005 Honda Recon 250 quad?

6. Is there a better/stronger rear shock that will fit on this bike? My son probably has plans for getting this thing seriously airborne("Dad, I cleared the house!!!").....and the stock rear shock looks a little weak...maybe a 1981-1982 ATC 250R rear shock?

[Name Brand]

I was able to do more damage to mine this year than any other. It's all been my fualt though.

At the start of the season during a day-ride, I found that something had hit my right side crankcase cover and put a two inch break in the aluminum case. (rock, stump...) I don't know how long I drove it without oil but it didn't damge the engine. Removed the case cover and had a local machine shop weld it closed.

My rear differential started clicking and the pinion bearing failed. That ate the ring and pinion gear up. I ended up swapping my diff and complete swingarm with one from a 1986 Fourtrax 250. I'm currently running the Fourtrax shock, but haven't decided if it's any better. Becuase water had slowly gotten into the differential I made sure to seal everything up and ran all my vent tubes into my airbox. This also moved the rear axle back three inches becuase that swingarm is longer.
http://www.3wheelerworldforums.com/showthread.php?t=55740&highlight=250sx+swap+gears

On September 1st, I endoed the trike at the top of a tabletop jump while riding at a local motorcross track. My own fault; got a little to excited and used too much throttle. The trike landed on me and rolled down the following hill. I broke my right collarbone and the top of my left fibula into three pieces. I flattened the headlight guard, bent the handlebars, unseated the outer bead on a rear tire, and cracked/bent the newly installed Fourtrax swingarm. I healed up without much lasting damage and fixed the damage and replaced the swingarm. I am amazed that I and the machine weren't hurt more. We were riding together again after only 6 weeks.

So, basically the damage that has happened to my machine has come from me; where I've been riding or neglecting to check my fluids. The SX is a tough machine and hasn't let me down on being able to go anywhere. It will go fast and also climb hills or go through boulder fields. I put alot of miles on mine and ran it hard this summer, it still runs strong and reliably.

[El'Capitan]

They are great fun, i spent some time in a gravel pit jumping ours,,,,,and it held up just fine to the abuse. It fires up right away, and no problems what so ever. A great bike for just riding, the electric start and auto clutch make it a great trail machine. Its a great trike.

[Tri-ZNate]

okay....a couple of other questions then....

1. Where can I find a magneto/ignitor/stator assembly? Supposedly, with both bikes, both had the same ignition problem....

2. Who makes aftermarket exhaust for it? Which one is the best? Loudest?

3. Are the carbs 'rejettable'...so you can rejet for the pipe mentioned in question #2?

4. If one train is traveling from chicago to los angeles, and another train traveling from los angeles to chicago, with both trains traveling 70 mph, both leaving at exactly the same time, when will both trains strike a car parked in Brazil?

5. How do these bikes compare, power-wise, to a 1997-2005 Honda Recon 250 quad?

6. Is there a better/stronger rear shock that will fit on this bike? My son probably has plans for getting this thing seriously airborne("Dad, I cleared the house!!!").....and the stock rear shock looks a little weak...maybe a 1981-1982 ATC 250R rear shock?


1. Servicehonda.com should have that or just put an ad in the classified section

2.Cobra is the only one I believe that still makes them brand new. Now other companies ares till out there like coffman, supertrapp, phase 5, jardine, bassani, and even DG. Most people dont like my Bassani because its so loud and my phase 5 has even more of a "ping" to it which makes it even worse :D.

3. yes they can be easily rejetted

4.

5. Roughly the same power but the SX will win in a drag

6. Works Performance shocks. www.Worksperfomance.com, they have a very nice aftermarket set-up and will set it up for your weight

[EvilMooseofDoom]

1. Servicehonda.com should have that or just put an ad in the classified section

2.Cobra is the only one I believe that still makes them brand new. Now other companies ares till out there like coffman, supertrapp, phase 5, jardine, bassani, and even DG. Most people dont like my Bassani because its so loud and my phase 5 has even more of a "ping" to it which makes it even worse :D.

3. yes they can be easily rejetted

4.

5. Roughly the same power but the SX will win in a drag

6. Works Performance shocks. www.Worksperfomance.com, they have a very nice aftermarket set-up and will set it up for your weight

5. The reason for asking? My brother's 250 recon hauls me around easily, yet tops out too quickly in the speed department (maybe 40 mph?)...indicating short gearing. I was given a quote of around 55-57 mph by another poster...is this realistic?

[chris200x]

I had my speedo topped out a little above 50 on my Sx. They might be geared a little better than say the big red or the trx.

[Tri-ZNate]

As with everything the mods you have done, tires size and rider weight make a huge difference. With my one SX and the top end pipe and 22" GBC Gators (mud tires) it topped at 61mph i believe with it bouncing off the rev limiter. 55mph should be hittable stock if you push it hard.

[Dirtcrasher]

I just picked up a pair of 1985 ATC 250SX trikes....one with a broken ring gear. How durable are these bikes? How does one break the rear end in one of these things? Should I build one of them up, or just part out the entire mess? Currently, I have enough parts to build 1 3/4 bikes, the rearend is missing the ring gear on one of them....

Is there some source for new gears?

in addition, just how "sporty" are these things? Are they somewhat maneuverable, or are they just as big of a tank as the same-year 250 big red?



The SX is near bulletproof and like driving in a Cadillac.

Change the front end to a 200X, change the pipe along with the airbox lid and install a 350X carb and you'll have a machine inbetween sport and racing that will never let you down except in a cas of complete neglect of maintenance.

Ebay has every part, fairly often.

An aftermarket shock is available, not sure how it works. I've launched and beat the hell outta mine in stock form for 7 years on the original shock.

The picture attached is an SX on a jump I hit often....

Great fun trike but I did learn from what others had said, and I do prefer my 200X for an MX style of riding over the SX. But when I want to ride wheeelies all day and be lazy, I break out the SX.....

[gplarryv]

has anyone heard o a clutch exploding on a on a 85, im looking at one and it sounds like the clutch came apart when you kick it over and the case is cracked larry

[PitboyJohn]

i love the sx.i mainly trail ride and it does very well,i can keep up with bigger 4x4 quads(except when we hit a real big mud hole,ground clearance)also good for hill climbs
i took mine thru an organized mud bog in oct and a honda 450 4x4 that went after me only got 5 feet past me.
as for reliability,it holds up awesome considering how badly i beat mine compaired to other bikes ive owned
just watch the rear end and as for the magneto,b 4 u go buying parts go over your whole wiring harness