Yamaha WR250R Mega Thread

[jon_l]

Check out High Five's site, and posts on ADV. Should be some info for you.

http://www.wrrdualsport.com/

Originally Posted by mikeysduck

Has anyone installed a 290 cc kit and had the crank balanced? Seems to me this would require adding weight to the crank to off set the heavier piston.

I got to ride a 290 cc kitted bike. It was geared lower than my stock gearing. It was difficult to feel any difference in power due to the lower gearing. I think the stock gearing is just right for any place I ride,

What I did feel was low frequency vibration in the pegs and some in the bars. When I got back on my stock bike, I noticed was how silky smooth the ride is. I like silky smooth!

I don't have to tell you, the faithful, how capable the little bike that could is. My lust for power has been in the back of my mind. I got incentive to follow up after a 50 mi. sprint via slab. It's not normal to long haul slab the little bike, but this is real life. At the end of a long day your looking for the short line back home. The long day read 253 miles on my ODO. The GPS read 230, 250 sounds better! Down shift to 5th and WFO in a heavy cross wind. In my road racers crouch, I had problems passing motorhomes going close to the posted 70 MPH speed limit. The wind gusts would drop my speed 2 to 4 MPH. The kitted WR just walked away. DAMN!

A larger displacement big brother, from Yamaha, would cause my cheap ass to run out and buy a new one ASAP.Hurry up Yamaha before I'm to old to care. I really don't want to get rid of the WR. I like the silky smooth do anything except slab in heavy winds little bike. In the mean time, I started looking for another bike with some cc's. A few extra FT LBS of torque sure wouldn't hurt.

[Bgunn]

Originally Posted by DefyInertia

Where are you guys getting your fuel pumps and what is a fair price these days?

CheapCycleParts.com $238 and $9.99 shipping, also had other parts with the order.

[fred flintstone]

Originally Posted by Mikef5000

The only one of those factors that would effect the pump itself is (b). Modifications and riding style make no difference, the pump is either on or off, not variable. Hot climates (or running hot) could be a factor as well.

This is quite common with FI dirt bikes though. A small amount of fuel (which acts as fuel pump coolant), mixed with lots of heat (stuck/slow riding), is going to be bad on a fuel pump, period. Regardless of bike/brand etc.

Thanks for your reply. Yes it is either on or off but it cycles to maintain pressure faster or slower depending on engine load. What I was getting at is any electric pump has a max flow rate, and at that point the electric motor inside it is cycling at its design limit to maintain fuel system pressure. This generates a certain amount of excess heat. Part of the design of an in-tank pump is that heat is dissipated by the fuel in which it is immersed.

Performance mods + hard riding + heavily loaded will cause higher demands for peak flow rate out of the pump. Low fuel levels + high engine & ambient temps & low speeds also increase heat effects as the fuel cannot dissipate the heat from the pump as well.

I was just guessing that many folks ride the shit out of these bikes loaded & modded (which is a good thing believe me) but maybe the fuel pump is too often at or beyond its design limits in a situation with a low fuel ( so poor heat sink) and so it fails. It would be nice to have a higher capacity aftermarket pump available or at least understand what factors are causing this so as to minimize the likelihood of occurrence. Then again I would expect Athena big bore folks to have the most failures if this is a correct thesis.

I am purposely not modding the engine til I understand this better, much of my riding is way the hell off and gone solo in the mountains and I really don't want to have to deal with a fuel pump going out @ 12k ft 30 miles from anywhere. High elevation makes heat problems worse as the ambient air pressure is lower, so its ability to absorb radiated heat is less.

Anyway so far the take away message seems to be, do not run out of fuel or get too low, esp while riding hard & slow, and if you do maybe ride more conservatively to minimize heat build up.

[Curbhopper]

Rode the Meteor ride this past Saturday and crashed big time, this swift moving pine darted out just as My front tire washed out in deep sugar sand. My bike gave the tree a kiss followed by a hug with me in between. This sweet embrace took the breath out of me and offered some small mystifying stars to gaze upon. While several riders behind are pulling the love birds apart to avoid rubbernecking, I regain composure and decency only to find my Alpinestar suit saved my right forearm from becoming two and the WR unscathed. We left the love starved Pine tree alone and broken bark ed.

Points I like to make:

1) The WR is built like a tank. (weighs like one too)

2) Alpinestar suit really works.

3) Radiator guard works for sure.

Protection gear for bike and rider is paramount for a great day in the woods.

[pfy50]

Originally Posted by NeilW

I cut a couple of holes on the back of the fan shroud, maybe that aids flow. Some people say they feel extra heat with that mod. I wear riding pants so not a problem.

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.

[jon_l]

Originally Posted by fred flintstone

much of my riding is way the hell off and gone solo in the mountains and I really don't want to have to deal with a fuel pump going out @ 12k ft 30 miles from anywhere. High elevation makes heat problems worse as the ambient air pressure is lower, so its ability to absorb radiated heat is less.

Anyway so far the take away message seems to be, do not run out of fuel or get too low, esp while riding hard & slow, and if you do maybe ride more conservatively to minimize heat build up.

Seems like a likely theory. I try to never let my tank get too empty for that reason, to keep the pump immersed.

I have read this entire thread, and my impression is that fuel pump failures generally aren't catastrophic, but rather, intermittent, and parking the bike for 20 minutes usually results in it starting and running fine (until the next occurrence). So I wouldn't hesitate to go out there on the WRR, and would replace it first sign of impending failure.

[fred flintstone]

Originally Posted by jon_l

Seems like a likely theory. I try to never let my tank get too empty for that reason, to keep the pump immersed.

I have read this entire thread, and my impression is that fuel pump failures generally aren't catastrophic, but rather, intermittent, and parking the bike for 20 minutes usually results in it starting and running fine (until the next occurrence). So I wouldn't hesitate to go out there on the WRR, and would replace it first sign of impending failure.

Yep I read the whole thing too. I guess one thing would be if it does go out and you are low on fuel, see if you can't get a little more fuel in there from a buddy or aux source, whatever, for cooling, then let it sit for 20 minutes and go. Some people seem to not have the pump completely fail after a few of these episodes so I wonder if you could get away with it w/o buying a new pump if it happened once or twice.

In my case i got a 3.1 gal IMS tank and never let it get much lower than reserve light coming on. That seems to be with 3/4 gallon left or so.

[what broke now]

" Yes it is either on or off but it cycles to maintain pressure faster or slower depending on engine load. What I was getting at is any electric pump has a max flow rate, and at that point the electric motor inside it is cycling at its design limit to maintain fuel system pressure."

My understanding was that the pumps ran constantly and either delivered fuel to the injector or bled it off through a fixed- pressure relief valve. There is a single "cycle" when the key is turn on, but I thought the pump ran 100% when underway. Is that not the case?

[fred flintstone]

Originally Posted by what broke now

" Yes it is either on or off but it cycles to maintain pressure faster or slower depending on engine load. What I was getting at is any electric pump has a max flow rate, and at that point the electric motor inside it is cycling at its design limit to maintain fuel system pressure."

My understanding was that the pumps ran constantly and either delivered fuel to the injector or bled it off through a fixed- pressure relief valve. There is a single "cycle" when the key is turn on, but I thought the pump ran 100% when underway. Is that not the case?

You may be right it would not be the first time I did not understand something.

edit:

"On most older vehicles, the fuel pump runs at a constant speed. But on many newer applications, the pump speed is varied by the PCM to more closely match the engine's fuel requirements."

http://www.aa1car.com/library/fuel_pump.htm

But even is the WR is variable rate I think you are right in general that the main cause is running the tank low under hot ambient conditions.

[Crawdaddy]

Originally Posted by fred flintstone

I have looked but cannot find any info as to whether bikes which see pump failures are mainly

a) modified with exhaust FMF, airbox etc. and so running a great deal more fuel

b) run the tank dry often, or at least low

c) ridden mostly very hard and/or heavily loaded

d) all of the above..

I have a 2008 model......it has 14K miles on it.......1K with the 290 kit......I fit in category (d).......and I have had NO
pump issues......I have to believe the failures are in the minority not majority.......oh shit, NOW I've set myself up for failure

[bigdon]

My bike quit in a bad place. We tested everything and put it back together. Battery was hot , would turn over but not start. Tank was full,cool morning,maybe 10 miles ridden.
We took fuel line loose from bike and tried pump. It would send gas out in a stream but not very strong.
We then pushed bike down hill and it fired right off. I rode it another 100 miles that day and then hauled it home.
I started and rode the bike with no problems 4 or 5 times while waiting for my new fuel pump t arrive.
I installed the new fuel pump and have ridden the bike probably 500 miles without indecent.

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?

[fred flintstone]

Originally Posted by Crawdaddy

I have a 2008 model......it has 14K miles on it.......1K with the 290 kit......I fit in category (d).......and I have had NO
pump issues......I have to believe the failures are in the minority not majority.......oh shit, NOW I've set myself up for failure

Do you frequently run the tank low or even empty? Also is yours an early production 08 model? Mine is.

[Crawdaddy]

Originally Posted by fred flintstone

Do you frequently run the tank low or even empty? Also is yours an early production 08 model? Mine is.

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#?

[ba_]

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

[what broke now]

"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 have not tried that, but I am pretty sure the relief valve is set for about 32psi [+-] so it sure should go more than a foot.