Yamaha WR250R Mega Thread

[fred flintstone]

Originally Posted by Crawdaddy

Frequently? No, not now that I have an IMS and Rotopax. But I did run it bone dry out of curiousity with both the stock tank and the IMS.....

Ok, I guess I'm a 100% (a), 10% (b) and 100% (c)

How would I know if it's early 08 vs. late 08?........do you pick that up from the VIN#?

Thanks for the info. Yeah it is the VIN # last 4 or 5 digits I can't remember. However some people w 09 models and even some with replaced pumps were also getting failures so who knows if that early VIN thing is still valid.

Another hypothesis. Low usable fuel tank capacity + super capable & wildly popular new bike + maybe pump placement in tank leads early adopters to run out of fuel a lot.

I was raised to never let EFI vehicle run out of fuel, so have always been careful with that but maybe the way the pump sits in the tank it is not cooled well or even at all at low levels. Who knows.

[Scott_PDX]

Originally Posted by ba_

What options do I have for connecting a relay for use with a fuse block?

I tied into a rear light (blue wire IIRC) under the seat and tied directly into the battery which worked just fine. However, I just recently went with an Eastern Beaver fuse box set-up (#3CS) to make things a little cleaner down there and give me some extra ciruits for lights/heated grips. It came pretty much plug and play, took 10 days or so to recieve it...from Japan.

http://www.easternbeaver.com/Main/Wi...3_circuit.html

[ba_]

Originally Posted by Scott_PDX

I tied into a rear light (blue wire IIRC) under the seat and tied directly into the battery which worked just fine. However, I just recently went with an Eastern Beaver fuse box set-up to make things a little cleaner down there and give me some extra ciruits for lights/heated grips. It came pretty much plug and play, took 10 days or so to recieve it...from Japan.

You still need to tie the Eastern Beaver fuse box to a wire like the rear light in order for the switched and un-switched circuits to work, correct?

[thumpididump]

Been trying to find a video I saw a while ago, and wondered if someone can help me find it again.

It was a short clip of a WR250R that was accelerating through a parking lot, and it suddenly looses power (like the fuel pump quit, or like the ignition stopped firing) for just 2 or 3 seconds, then the problem went away. Just a momentary loss of power from fuel or ignition problems.

Anyone know which video I'm talking about?

[duanew1]

Originally Posted by bigdon

Has anyone else tried to shoot a stream of gas with the fuel pump unhooked from bike?
Did it dribble out maybe a foot or so like mine did or did a shoot a high powered stream like I think it should?

I believe that the fuel pumps are more of a pressure pump than a flow pump due to the low flow requirements during operation. I would think that the fuel hose is a very large orifice (in comparison to fuel jets) which would not allow pressure to increase to a long shooting stream. A smaller opening would probably shoot farther.

On the other hand, I think that this might be a good way to kick start a stuck pump in the field if needed.

[Scott_PDX]

Originally Posted by ba_

You still need to tie the Eastern Beaver fuse box to a wire like the rear light in order for the switched and un-switched circuits to work, correct?

Yes. There is a lead ready for you to splice into the line. I think he provides one of those posi-vampire crimp things as well. But I try to solder all my connections.

[NeilW]

Well dang, hadn't thought of it that way. I guess the flip side is - when the fan is not running, the air flow through might be better. The holey shroud theory is probably right up there with those people who swap out a 190° thermostat for a 180° unit thinking it'll run cooler. The thermostat opens sooner but max cooling is not improved.

Oddly enough, the only time my temp light ever came on was when I was on the freeway - doing about 70mph, slightly down hill so not at full throttle. I think the stock fueling is lean at less than full throttle. On the other hand, I've pulled long inclines WFO and the temp stayed in the good range. I have one of those cheesy radiator cap thermometers to help me worry about engine temp.

Originally Posted by pfy50

Hey NeilW,

I am thinking that the Mod is feeling the extra heat because it is in fact damaging the efficiency of the fan to pull air away from the rear of the radiator. The purpose of the shroud is to direct the air& heat coming thru the radiator to the fan for removal effectively. If you put holes in the shroud it no longer is working as designed. To move more heat away from the engine you make the radiator larger, the fan larger or the same fan faster, or some combination of those three.
Just imho.

[Krabill]

Many people, myself included, remove the rear shroud all together. I occasionally ride slow, tight, technical single track in 100 deg weather and have never had an overheating issue.

[KansasBob]

Originally Posted by NeilW

Oddly enough, the only time my temp light ever came on was when I was on the freeway - doing about 70mph, slightly down hill so not at full throttle. I think the stock fueling is lean at less than full throttle.

Some have found the high speed over heating is cured by cleaning the air filter.

It seems to me the actual surface area of the air filter on these bikes is much smaller than than what I'm used to.

[tmotten]

Originally Posted by duanew1

I believe that the fuel pumps are more of a pressure pump than a flow pump due to the low flow requirements during operation. I would think that the fuel hose is a very large orifice (in comparison to fuel jets) which would not allow pressure to increase to a long shooting stream. A smaller opening would probably shoot farther.

On the other hand, I think that this might be a good way to kick start a stuck pump in the field if needed.

You're one the money. Velocity is a function of orifice and volume. Increase the orifice and the velocity goes down. Not sure if this system uses a pressure regulator, I haven't studied this bike yet. But the pressure achieve in the manual can only be achieved with some back pressure either through an orifice blockage or narrowing or regulator.

On the bm Dakar the fuel pumps are prone to fail when the tank is allowed to run dry often. The fuel is used for cooling the pump. I guess the materials in the pump overheat and expand in different ratios which would/could result in loss of pressure inside pump. This will move the duty point in and area of the pump curve that will exacerbate the situation until failure. I guess letting it cool back down would correct this, but my guess would be that key materials will fatigue early in its design life cycle.

I'm no pump specialist, but dabbled with it a bit. Centrifugal pumps though.

[OldPete]

I have to move so I can have a secure garage. My tools are in storage.
Once move, it will be soon, an R2 will be bought. If I take the 3 month ride a new pump installed and the old unit carried.

The KTM and Husky bikes of '08 had this same issue but fewer are sold than Yamaha and are ridden fewer miles.

Scroll down on page 11 and continue to what he found and how he removed too much material.... http://wr250rforum.forumotion.com/t1...ight=fuel+pump

[fred flintstone]

Originally Posted by OldPete

I have to move so I can have a secure garage. My tools are in storage.
Once move, it will be soon, an R2 will be bought. If I take the 3 month ride a new pump installed and the old unit carried.

The KTM and Husky bikes of '08 had this same issue but fewer are sold than Yamaha and are ridden fewer miles.

Scroll down on page 11 and continue to what he found and how he removed too much material.... http://wr250rforum.forumotion.com/t1...ight=fuel+pump

That is a great thread, thank you.

[ba_]

.

[Longboardr]

Originally Posted by ba_

I'm trying to find a place online to purchase the longer pinch bolts needed when I mount the Cycra triple clamp side mounts for handguards.

*** Edit:

I found this:

http://www.probolt-usa.com/stainless...l#.UJPrLGl26To

Check McMaster Carr too

[Crawdaddy]

Originally Posted by ba_

I'm trying to find a place online to purchase the longer pinch bolts needed when I mount the Cycra triple clamp side mounts for handguards.

*** Edit:

I found this:

http://www.probolt-usa.com/stainless...l#.UJPrLGl26To

I picked mine up at a ACE hardware store.....same exact bolt/head