250-500cc Next Project - 6 speed WR 250

half throttle in the snow you will need more than that to get it moving, lol
sounds like youve got a transformed bike in the making do keep us posted.
and good luck with the race, are you just setting timing and going from there or will you be tinkering a bit to see if you can feel the sweet spot?

msmith345, How did the PVL install go?

Well, I'd like to say it was completely painless, and when together, the beast fired right up with glorious vigor.

...but that's not the case. It calls for a non-resistor spark plug and I did not have one. Needless to say, all back together, and I didn't get it to fire in the 20 degree garage. I've got some spark plugs coming, as I went to 4 places over the weekend and couldn't find any of the ones I needed. So...yeah...we'll see after those arrive and I get things fired up.

The actual install was pretty simple with the timing dial indicator. I have no idea how you would manage to set it without that. Probably the most difficult part was unbolting the regulator, as my radiator brace/hoses were in the way. But I'll reserve judgement until I figure out how it starts.

Well, at least you got it mounted.

Doing it without the dial indicator you'd just be guessing, and timing is no place to guess.

These 6 speeds are not a close ratio?

Sorry to do this, but that PVL #70049, is that just the CR ignition, or is that an aftermarket unit?

There has been much interesting ignition talk lately, and I am struggling to get the different options straight.

I'm very interested in doing something on my WR, but I need to retain the ability to run lights.

It's an aftermarket setup. A bit old school, popular with the vintage crowd. I wanted a CR ignition, but I never found one, and I was wanting to get my bike back to running and get some winter riding in. So, I took a chance to see how the PVL will do. Jury is still out, until I get everything sorted. This Snowpocalypse part 2 that they're saying is coming in a couple hours will probably delay the UPS guy, so it will probably be a bit later this week before I have any kind of update.

my understanding is the cr = close ratio and the wr = wide ratio, i thought it was the gearboxes they reffer too, i think mid 2000's are all close ratio gears even on the wr models but i may have got this well and truly wrong, wouldnt be the first time.

Yep on the WR and CR meaning ... I just got lost with the what this base 6-speed was all about after seeing the larger front sprockets and top speeds in the thread...

ah right yes its a 360 wide ratio 6 speed box in his smaller cc engine, top idea less rotating mass with a higher ratio of gears

You got it right. Sometime after the early 2000's, all the bikes started coming with the close ratio box, regardless of whether they called it a CR or a WR; there were other differences between the bikes (electrical system, suspension, etc), but not the transmissions.

A lot of guys want to switch to either the older wide ratio 5-speed, or the 6-speed.

Well, the bike is almost ready...however, I've got a couple of issues. Either I've got a timing issue, or I've got my Lectron all screwed up, or both.

The bike finally fired up last night. It wasn't getting fuel, so I tested by dropping a little in the cylinder, and it fired right up. So, I pulled the Lectron apart and cleaned it up. Adjusted it a bit, put it back together. It fired up after a couple kicks. Very loud and a real high idle. So, tried the screw on the Lectron, with no affect, so I shut it down. Pulled the Lectron back apart, went a full turn richer, put it back together and gave it a shot. Fired up, was still too high of an idle, started messing with the screw again. Had it going a little longer this time. Revs started to climb. Hit the kill switch, nothing. As the fear of a fried engine got me to a panic, I pulled the spark plug wire. Managing to shoot 50k volts from the coil through me in the process. That's one strong spark, we're talking like 6 inches it arced to the plug -- or at least that's what it seemed, my vision might have been a little blurred. Anyway, that's where I stopped last night.

The timing recommendation was between 70 and 85 thousandths. I've got it set at 75 thousandths. So, I thought that would be retarded and a bit on the safer side.

So, here are my thoughts:
Fueling
If the carb is getting fuel starved, the engine is going to run increasingly lean and rev up.

Timing
If the timing is too advanced, it could be running hot, causing the rise in RPMs and need the timing retarded.

Anyone see any problem with that logic? I'm still concerned about the high idle and the loudness, since I haven't had that issue before, I'm thinking at least that part has to do with the timing. The recommendations were fairly generic based on the displacement of the engine, with a lot of disclaimers about porting and carb and pipe all affecting it. I think I'll do some math today to come up with what the recommendations convert to in degrees and compare to the digital timing curves to make sure I'm in the ballpark of the factory. Then I should hopefully be able to sort the RPM spike with fueling, since that started after the bike was running maybe 30 seconds, and the Lectrons do seem to be sensitive to the fuel level in the float bowl it seems like it would be the likely cause.

I'm not running race gas, I run BP premium, so 91-93 octane with no ethanol in it, same as I always run at 40:1 with Amsoil Dominator. The gas has been sitting a while, but it shouldn't be too far gone.

I sounds like it's way retarded to me, but it could also be way advanced. The reason I say retarded is that fact that you say it's loud. That tends to indicate that is firing with, or close to, the exhaust port opening. But, it could be that much advanced, but then they tend to want to run backwards.

It's not running backward, is it?

To be honest, I'm not even sure how I would go about checking that. Would the easiest way be to start it, then shift it into gear (with the bike on a stand) and look if the tire spins the wrong way?


Comparing the numbers, the recommendations work out to be between 9* BTDC and 11* BTDC. At 75 thousandths, it is 9.5*. The stock curve starts at 10*, then drops to 7* by 2k RPM, then jumps to 26* at 3k RPM. Then drops slowly until 9* at 12k RPM. So, I don't think there is anyway that I could have it too far advanced, could be questionable on the other end though. I can try advancing it a degree, to 10.5* and see if that has any affect. It makes a lot of sense what you said about possibly having it retard too much, if that fuel is still burning when the exhaust port opens then yeah, it should be a lot louder.

I've seen engines with a lot of advance actually change direction if they idle down to far. I know it sounds crazy, but it can happen. I wouldn't put it in gear if it is. My brother did that once and tore up a bunch of stuff. He actually was going to try and ride it in reverse, but he didn't make it very far.

I'd run it with the flywheel cover off and see if you can tell, but I'm still leaning toward being too retarded.

Do you have a timing light? Might invest in an inductive battery powered light. They're pretty cheap, but it's a big help in an ignition swap.

You can use your dial indicator to make marks on the fly wheel, or use it with a degree wheel. There are calculators online that can give you can degrees in distance from TDC. Once you find TDC, then you can make the wheel at different points and use the light to get an idea if you are actually where you think you should be.

it's an interesting concept of a two stroke running in reverse, I had a snowmobile that when idling you could pull a button and the engine would run odd for a few seconds then run backwards, handy when you need reverse but interesting none the less

Yeah, hot rod snowmobile and jet ski engines are notorious about that. Usually when they have an ignition that retards way back at low RPM and a lot of compression.

jet skis have reverse???

Every modern mountain sled I've ever ridden does reverse by changing the direction of the engine. Pretty cool!

I second the idea of making some scribe marks on the flywheel and using a timing light. Anything else is just guesswork. I'd put it at TDC with your dial indicator and use a degree wheel (or just math) to mark it at a few increments, like 10/20/30 BTDC. Then fire up the timing light and you'll know exactly where you are, no more screwing around.

mine was an RMK 800, very cool, with my wife on board it was hard to keep the skis down having fun, alone was insane