1989 RM250 wanting more range...

Ok I have a 89 RM250 and she is really thirsty compared to my friend's crf250x and I'd like to increase my range.

Did the RMX have a larger tank than the RM? How much larger?

I can get a 4.7gal tank that fits my bike, but that is just too much added weight to slosh around.

There is a 3.4gal tank for the newer RMs that I could make fit, but then I have to also buy the matching radiator shrouds.

Or i was thinking of buying a couple of those Stainless steel water bottles and carrying one in my camel back and another in my fender pack.

Im hoping the RMX tank is larger because I'm eyeing one up

So what would you guys do?

I had an 89 RM 250 and Its an awesome bike! You should be able to run 40+ mins on a tank of fuel. Yes the CRF will get better mileage because it isn't a high strung closed course race bike. The RMX tank should fit.

Good luck.

The RMX tank holds 2.9 gallons (including reserve.) It should bolt right on.

I LOVE my bike I keep it in mint shape it has enough power to hang with the 450s all day long :excuseme:. Does anybody know how big the RM gas tank is? I don't feel like filling my tank, then draining it to measure the volume.

I LOVE my bike I keep it in mint shape it has enough power to hang with the 450s all day long :excuseme:. Does anybody know how big the RM gas tank is? I don't feel like filling my tank, then draining it to measure the volume.
MX tanks are usually under 2 gallons. I think the last generation RMs came with a 1.9 gallon tank. I am running the IMS 3.2 tank on my 04 RM250 when I need more range.


I have an RMX tank on my '90 RM. It bolted directly on and uses same shrouds.

Not always a pretty option, but Acerbis makes auxiliary tanks that double as the number plate too.

Offers almost a gallon extra capacity.


I forgot about those...hmm. Its a woods bike so i can deal with ugly functional mods :banghead:

Your stock fuel tank should be at or about 2 gallons. I have a 92 RM 250 and its fuel tank is 2.2 gallons. Ive looked into the larger desert tank for my bike also but all I was able to find was either the clark or IMS tanks that are 4.7 gallon. I thought the same thing you did thats lots of weigh and slosh. But then I found tank foam. Race cars use this stuff to prevent slosh. The tank foam only prevents about 10% of your total capacity. Even if you only put 3 gallons is the slosh is not noticable. Just my 2 cents worth on the larger tank with tank foam it works good for me. Hope it can for you also.

Thanks for the input guys. I'm pretty sure I'm going to go with the RMX tank and see how it works out for me.

i get around 40 miles a tank 2.1gal on faster less technical trail. Not putting but hauling arse.

I use the clarke 3.4gal tank for longer range uses stock shrouds 02 rm250

I just bit the bullet on a RMX tank. I'll keep you guys updated

Well I got the tank today. Right now I'm working on cleaning it up so it looks as good as the rest of the bike.


90 RM250 with RMX tank

Okay, well I finally got around to mounting my new tank and the seat will not fit properly. Because of the new tank the "hook" on the seat that slides into the frame won't slide in anymore. If i push down on the seat really hard I can kind of get it to slide into place, but the bolt holes still won't line up. If it comes down to it I can do some cutting and welding on the frame to make it work, but i'd rather not. Any suggestions?

You may try using the tank mounts off of your old tank. I think that is what I did. My tank came off of a 91RMX.

how far off are the mounting holes? Are they just slightly off?

I also have to press a little to get the frame/seat hook in the middle of the seat base to hook on my bike, but it isn't a big deal.

I have run the stock and SDG seat and they both fit the same way.

the hole for the tank are spot on. the holes for the seat are off by about 1-1.5 inches. When i push down on the seat its puts a considerable bend in the seat and i dont want to sit in a "U". I could get pictures up later or tomorrow.

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