92 WR250 Power Valve Woes

[gregp]

are your frictions OEM?

I noticed barnett frictions just didn't fit right, but OEM did, and I could finally rev the bike in 1st gear without it lurching away from me.

+1. Over the years, with experience with many different bikes and clutch plate manufacturers, I have found the same thing. Stick with the OEM friction plates if you want trouble free installation and operation. JMO. I also stay away from "heavy duty" springs. In most cases, they seem to cause more problems than they resolve.

[Kurlon]

I didn't get a vote on what plates were in it, and at the moment I don't have the budget to swap them all out for OEM at the moment so I'm just trying to improve/diagnose what I've got.

[Kurlon]

Took the clutch pack out again to look it over. Pressure plate has OEM range of movement, so it's not my perch/lever setup, a bad cable, etc. So that's good. Pressure plate lifted, hub does not want to spin free. Pressure plate off, hub does not want to spin free. Try to pull the individual discs/steels out, and it all wants to move as one piece. The plates are suction-cupping hard to each other. The steels continue to stick to each other once pulled unless I de-oil them. Nothing's warped, stack height and individual plate thicknesses are good. I need to find out why the plates are sticking to each other it appears.

[Paul_E_D]

Steels stick to each other??? They shouldn't be touching each other, right? frictions touch steels, but you know that. Are you saying that the steels stick to the frictions?

I think just ride it more and change the oil. Then, when you can afford it, get OEM clutch pack.

[Kurlon]

The steels stick to everything. When I first pulled the pack I could hold it up by the top unknown friction, the rest just stuck there... now that they're apart if you stack two steels on each other with any overlap, stick. De-oil them and no more stick.

The OEM fiber seemed to be much less inclined to 'stick' to steels than the unknowns, so I think I'm going to break down and order a set of OEM fibers tonight just to have them. I'm too damn close to this bike being 'right' to stop now. If only new kickstart levers weren't so stupid expensive I'd sort that minor annoyance too. Might try to find an aluminum welder to deal with that.

Meanwhile... I've got a bottle of ATF Type-F staring at me too...

[Paul_E_D]

Yeah, ride it more and get the OEM frictions later...

[Kurlon]

I've been abusing it for two years already trying to sort the drag, I'm not going to have a botched start at Stimilon this year!

[tls25rs]

I've been abusing it for two years already trying to sort the drag, I'm not going to have a botched start at Stimilon this year!

Pretty sure your clutch isn't the reason you left with the Women's wave last year

[Kurlon]

Pretty sure your clutch isn't the reason you left with the Women's wave last year

Hah, actually that was a big part of it! My first race I stalled at the gate because of the crazy clutch drag that got immediately worse if you blipped the throttle. For the second race I came up with a new 'launch plan' to avoid that issue: Keep it in neutral, wait for the gate to drop, bang it down and stab the throttle. Going through that in my head I saw the gate drop and bikes pulling away out of the corners of my eyes, spaced on the two wave start and executed my plan in a panic. D-Oh! Realized what I did by the time I was halfway out of the start area, didn't see anyone waving me off and figured stopping on track was bad so off I went.

[Rada]

I can't believe I missed this thread. I used to live late 80s to mid nineties YZs.

The draggy clutch is almost always due to notched basket and hub.

Are you running Yamalube R? You should. Mix it 40:1. Pull it apart twice a year and give it a quick cleaning.

Should be running a NGK 8 heat range plug.

Generally you can lean the needle one or two clip positions and drop one size on the pilot jet. This will crispen up the bottom end.

What did you get for a pipe? Noleen and Bills work well.

My 93 YZ was easily the very best MX bike I have ridden to date.

Have fun.

[Kurlon]

Basket and hub are just showing polishing spots at the wear points, can't actually feel them with a fingernail.

Premix is BelRay H1R synth at 32:1. I *may* have run 4 full tanks of gas through this bike total since I've had it, was torn down to the cases, new seals, gaskets, Eric Gorr 265 with 'mo betta' porting and reworked head two years ago. Suspension redone by Factory Connection last year.

NGK 8 plug.

Carb is actually working pretty good, good response across the board now with the new FMF Fatty on it. Dunno as any other makes are still on the market for this antique.

[Kurlon]

Post Stimilon results - All those who said "Get OEM Fibers Fool!" were 100% correct. OEM fibers and that clutch worked beautifully.

Carb setup on the other hand... WAY fat on the main. That's my next order of business to fix.

[Paul_E_D]

You didn't get it sorted today?

[Kurlon]

You didn't get it sorted today?

No, I thought I had some large Mikuni hex mains, turns out I had a 400, the 390 that was in it, and an old crusty looking 350. Between a poor jet selection, and not being 100% certain I had enough oil in the transmission, and being slightly tired (Neck in particular is sore) I played the lazy card today. Chatted for a bit in the morning, took my time packing, then trundled up the highway. Bike will get an oil change, I'm going to order a range of mains, then I'm going to hit up MX207 unless a 101 trip comes up that works with my schedule first.

[Kurlon]

Mains and pilots ordered, hope to have them Friday.

[Kurlon]

New brass installed, now I'm just waiting on some tech assistance from Moto Tassinari on how to adapt the VForce 3 reed block setup they sent me before doing a test and tune at MX207. Waiting to see if they suggest taking a hack saw to my carb boot, or getting a 96 YZ250 boot that doesn't have the tangs that protrude into the reed block. I'm leaning towards the YZ unit as the passage better matches the VForce reed block, but they're designed for a 44mm OD carb spigot, my carb is a 43 so it might not seal... good thing is I can snag one off ebay for $25 to play with rather than spend $100 on new. Worst case I've got a set of carbide burrs that'll port match my WR unit to the VForce if I have to.

While waiting on that I decided new front pads were in order given they're worn to nearly the backing plate... or so I thought. Pulled the wheel after fighting the caliper off as I have had to do since getting it. The pads have a sweet curve to them, nothing on the inner or outer edges, nearly full meat in the middle. D-OH! Rotor is similarly skinny in the middle of the swept area, fat on the inside and outside. The pads were retracting properly, but thanks to that bevel the middle of the pad liked to hang on the thick outer edge of the rotor. New OEM rotors are $150, ebay used units are $80... Tusk regular or wavy jobs are $60 brand spanking new. I think Tusk will be the answer, just have to decide if I want wavy or not.

Oh, I'm finally going to replace that worn out kickstart lever too, getting sick of having to be spot on with my kick so the slop doesn't prevent it from getting a full spin. No eBay deals to be found for it unfortunately, or aftermarket... OEM pricing sucks.

[Rada]

On the mains. IRRC 340 should be pretty close. But every bike is different..

[Paul_E_D]

Wirelessly posted

I always modified my boots for the v force. Cutting the tangs off is fine. Port matching isn't even needed as it doesn't show results on the dyno.

[breakdirt916]

Post Stimilon results - All those who said "Get OEM Fibers Fool!" were 100% correct. OEM fibers and that clutch worked beautifully.

Carb setup on the other hand... WAY fat on the main. That's my next order of business to fix.

awesome!! crazy how that works eh? looking at the steelies and frctions, you'd never know. plug in the oem parts and poof! it somehow works

and btw, I remember being next to you at the starting gate last year, and doing the same thing. I revved the piss out of the motor, had the bike lurch forward and wedge the wheel into the starting gate, then stall the bike while everyone else rockets forward. I look at you, you nod your head, as if you're saying "ohhhh great.", we kick start and go. good times...

btw, f the jetting. I bought almost all the jets you could buy for that carb, and honestly, it didn't make much difference. The bike still friggen runs, right? good, leave the jets in there unless you foul plugs too often, it doesn't idle, or the engine won't rev to redline!

[Kurlon]

Spent the weekend in Central Maine riding the trails with my parents and wife. She was on a new TTR125LE, they were on a Suzuki 500 ATV, and I was packing an ICBM for a round of tidily winks. 65 miles of railroad beds running between 15 and 30mph while my wife learned this whole new off road thing.

The WR hated it. It drooled pretty badly from the exhaust joint, but never actually fouled the plug despite obviously loading up at times. 99% of the time I was either JUST cracking the throttle of the idle stop, or closed and coasting. When I could I'd hang back a touch and hammer it to clean it up, right to the pin and it was right there. The rest of the time it was sputtering and not happy.

40 pilot, air bleed is at 3.25 turns, I know I need a 37.5 pilot but haven't gotten one yet. I have a 35 but wasn't able to get it to idle with it before. Needle is lowered one notch from neutral. 360 main.

Do I try dropping the needle one more? The plug was jusssst starting to show color instead of black after MX101 with the same settings. The engine would clean up by 1/4 to 1/3rd throttle. Or is this just too fat a pilot spoiling the party and I shouldn't bother mucking about until I get the right pilot?

Or should I stop trying to make the bike putt and get a beater thumper for the job so the WR can scream like a banshee at the track? (Turns out my wife loves trail riding, there will be lots more of this in my future.)

[tls25rs]

You should buy that TTR125L from the other post so you have something that is comparable to your wifes bike to ride with her................................

[Paul_E_D]

Try dropping the needle.

I can't believe the bike that wouldn't idle with a 35 would be blubbering with a 40, but maybe. You might end up back at a 35! perhaps there was a different issue.

[Paul_E_D]

Oh, and the WR SHOULD be able to chug around all day with the right settings. That's kinda what it was designed for...

[KB]

I miss my WR!

KB

[typeone]

yeah, keep leaning out the lower circuit. bet you can clean it up. your air screw is way out now, get that 35P

curious what premix you use? ive been trying oils with different flash points for different riding conditions. lower flash point = better for lugging around trails. oil with higher flash point = ripping MX racer or deep sand WFO

this wont solve baseline jetting issues but will help if the oil youre currently using has a high flash point.