fuel tank

well my 05 yz450 has a smaller tank than i thought:thumbsdn: i thought it was 2.1 gal and after checking the manual i see its 1.85. this is somewhat of a problem as i need to go 2 hrs in my HS;it wasn't a problem before because last yr i had a clarke 2.8 on it and in a effort to streamline i put the stocker back on and sold the 2.8 to my buddy thinking that the 2.1 will be plenty as our races never total more than 30 miles. after a practice run of 2hrs equaling 28 miles of singletrack in non stop race pace mode i was shocked to see there was basically no gas left when there should of been at least a quart(i average 15/16 mpg at race pace) thats when i looked it up to see 1.85!!sooo... as this is not acceptable i need to get a larger tank,1st;is there a stock 2.1 tank(03/4)? that'll fit the yz seat and shrouds? and maybe i oughta just get a IMS? i'm somewhat leary because i've heard a few issues with the crossovers and such. i don't want to go back to a clarke as they are way wider and carry the load too high. any suggestions:ride:

AFAIK, you have two choices other than the Clarke:

The stock WR tank (you'll need a seat and shrouds)

The IMS.

All of the OEM YZ450 tanks are 1.8 Galllon regardless of year. I have an IMS for the desert, and while I don't like how far down it drops on the sides, and I'd rather it had two petcocks instead of a crossover, it is otherwise a pretty good setup, and is pretty unobtrusive when riding.

I've heard of people expanding their stock tanks by pressurizing them for a while, or something like that. Maybe somebody who has done it will be able to chim in. I think you could get a 1.85 to be 2.0 that way.

I thought the 03 WR had a 2.8 gal tank.It should fit the YZ as I just put on the 3.4 gal IMS sold for the YZ on my WR.Seat works fine ,but the new tank had 2 mounting spots.I have it if your interested.

i ordered up the 3.4 IMS;what a bunch of mass confusion that was! some sell it as 3.1, some as 3.4,and yet others call it a 3.0;but come to find out its the same tank,it hold 3.4 but only leaves 3.1 available for use:crazy: i spent 2 hrs with different parts people,talked to IMS the secsatary didn't know,called back the parts people and got part #'s,called back IMS finally got ahold of a tech who filled me in that the advertised 3.0/3.1/3.4 were all the same tank:banghead:

gray apparantly the new style has no crossover to have issues with,the feller said that worse case scenario only a half gallon would get stuck on the right,and then you just tip the bike! kinda archaic form of reserve!

thanx for the help:ride:

somewhere here i saw a link to a place that sells some sort of aircraft tank foam that acts as a slosh stopper and only takes up 5% volume,i think i'm gonna try it out if i can find it again.

found it! its from weapon MX.

What's always amused me is how IMS expects fuel to run from the bottom of the left side of the tannk, where the petcock is, UP to the carb. I guess you have to run out, stop, pull the gas cap, blow into the tank to fill the float bowl, and ride again 'til it runs out again, I don't know. :applause: Seems pointless and in the way.

that's for the backflip at the finish:prof:

that's for the backflip at the finish:prof:

Ah haaa......

well i got the ims and all i got to say is....what a freekin' abomination this thing is,its going back where it belongs! there is no crossover and there is no way in heck the fuel is gonna work its way back to the other side,and the fuel line routing is kinda screwy too. its not as "slim" as they state either.

so it goes back and i ordered up a 05 wr tank which is supposed to be 2.6 gal(according to the yami advertised spec) but the service manual states 2.1 w/.3 reserve:excuseme: either way(2.4 or 2.6) thats all the extra i need and i remember from my 04 wr that the tank is not too invasive. only problem is i had to get wr shrouds(it was time for new ones anyhow) and will have to monkey with the seat/tank mount. i did order up some of that foam and it'll probly fit in the wr tank with some trimming:thumbsup: nuthin's easy:banghead:

I have the Zip-Ty (Can't remember if Clarke or IMS makes it for them) oversized tank. I don't currently have it on the bike, but when I used it, I got the optional petcock for the right side (it's a round Black anodized knob on a red housing), and used the standard stock Yamaha petcock on the left side.

By using two fuel lines that came together at a "y" or "t" fitting, you can either run both tank's sides, the left only, or the right only, or shut both off for storage/transport. You can't usually draw the last few inches of either side (below the fuel bowl) but overall it works well.

2004 Yz450f

Hey Bob, this won't add to your amount of gas but will your peace of mind, put on a WR petcock with reserve.

I put on an IMS 3.X tank (natural) for the Hare Scrambles up here and have found it to be just the ticket. The hoses for the crossover are added (I think, bought it lightly used) but I have not had any issues with it. The only thing I can only complain about is that I find it just a little bit less "grippy" when squeezing with my legs (standing up). Other than that, I don't feel the extra weight/width/size at all.

On a side note, one thing EVERYONE should add to their trail bag, I found a plastic gas tank sealer at Ace Hardware that works absolutely incredible and is only $2. I sealed a complete hole from one of the crossovers on the IMS tank and have two races under my belt with it with ZERO issues.....get some, might save your day.

So for a dune rider that goes through a lot of gas what would you reccommend as far as riding ability being compensated for storage? I want to buy the biggest tank I can but I don't want it to adversely effect the way I have to ride my bike. Maybe I just need to stay off the throttle a little more.

well i only needed enough to finish a 2hr race comfortably; 1.85 gal was empty @ 2hr so the extra 1/2 gallon or so of the wr tank will be perfect:thumbsup: mark,i'm just gonna use the yz petcock without reserve as i've found they tend to run out right when you need it;then ya gotta fumble around and switch it over.... i'd rather just run it knowing there is enough gas to do what i need.:applause:

With a reserve in the petcock, you can have it either way. If you want to run the whole load of fuel out in one streak, like a racing petcock, just put it on reserve to begin with.

Those of you with the IMS tank.


Did you follow thier instructions and make a Loopy with the 20" of fuel hose, over the air boot and into the carby (basically a giant Q with the hose) or

Did you just go in one straight shot, up and to the carb?

I've done the loopy thing but it seems really queer. What is the reasoning for this?

06 WR450 is simlar to the older YZ models like Greys 03 etc.

Some of the 450's, like mine, have an L shaped tube fuel inlet pressed into the carb body, where some other models have a brass swivel fitting. If yours swivels, just make the line run straight up to the carb. Otherwise, looping it around like the instructions say is the only way to keep the hose from kinking, and keep it out of the way.

Another thing about the crossover, if you have one. There is no shutoff on the crossover line, so what if the tank has to come of in the field, hmm? I loop the crossover up over the air boot (intake bell) so that I'll be able to raise the tank far enough to get at the spark plug without draining the tank, or spilling gas all over while I juggle the fuel lines around in the process of pulling the tank.

Sweet answer.

Yeah, I guess the WR models have that swiveling brass fitting, so I'll just do a straight shot at it then. The Curly Q just didn't make sense.

I do NOT have the dual petcocks for the exact reason you mentioned, which I read before purchashing the tank.:applause:

I'll just lean it over or rely on one of my many crashes to do it for me:busted:

Dual petcocks would be fine, but I don't think there's room for one on the right side. There's barely clearance for the crossover fitting. IMO, the tank drops way too far on both sides.

I was VERY surprised at how tight the tank (and the attached crossover piping) fits to the cylinder. I would wonder about overheating and fuel boiling if I were using it like I used the stock tank in Florida....hot hot hot. Up here in Colorado, we don't have that kind of heat, so cooling is a given for the most part.

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