BS 200 Ice Racer

[scrambler]

First race bike build. Never raced anything. Local ice racing scene is pretty popular up here in NW Wisconsin so I thought I might as well go for it. I have about 25 of the 175/200 bikes so I guess my mind was made up for me. I started with a bike that must have been some sort of race bike at one time but it was incomplete and the engine was sitting open for who knows how long. It did have some chambers on it and the frame had already been modified a bit.



I stripped it and cleaned up and removed some of the stuff that was on there.



I picked a 200 donor bike from the pile that seemed to have a good engine in it and started swapping in parts.




Mocking the whole thing up before I open up the engine and make a few mods. Deleting oil injection, modding the rotary valves, total loss ignition, etc.

I'll be in a class that runs 230cc max 2-strokes and 250cc max 4-strokes. Studded tires. Brakes front and rear. Have to fabricate full coverage fenders as well.

I'll be up against mostly modern off-road MX bikes only slightly modded to run on ice. More than likely I'll have my work cut out for me. Its still bound to be fun. Right?

Trying to figure out what to do for tires or possibly swapping in some different wheels. The wheels are only WM1 and they don't make actual ice tires for anything that narrow.

Any ideas or comments welcome.

Kevin

[rocketman]

  Great project,Kevin. I like the concept. You may find you surprise some of the newer bikes.  Mark.

[scrambler]

Well  hopefully I'll get that chance to find out.

[scrambler]

I pulled the 200 engine apart to make sure it looked ready for abuse.




I also have most of the modified 175 engine that came out of the modified chassis. Pistons are modified and it wasn't a hack job. Valves also look to be cut back slightly.



I was almost thinking about using this 175 top end on the bike since its already modified. I also like the idea of having a go at making some changes to my own pistons.

[Toystoretom]

In the picture of the 200 crankshaft I see a crank seal in the middle between the two counterbalance weights. What is the condition of that thing? It seems like every two stroke I mess with has bad crank seals (or they are so petrified from old age they are getting ready to go bad). If that seal takes a crap it's doubtful the bike will run.

Has anyone on here replaced those seals? I've been sending my cranks out to Bill Bune Enterprises and he tears the crank down and I have him put in new bearings and seals. It's not too horribly expensive but it ain't cheap either. One of these days I'm gonna try it on my shop press with a junk crankshaft just to see if I can do it. The big problem is that the crank must be trued up after it is pressed back together.

[scrambler]

That's always the problems with multi-cylinder 2-strokes. Those darn seals. This one seems ok and I think I'm going to risk it at this point. The crank in the 175 seems to have some of those non-rotating bearings installed.

[reed]

Toystoretom
I have all the equipment to strip down and rebuild cranks plus the truing stand for checking for runout on the crankshafts.
Its a lot of fun doing or own crankshaft and then putting it back in the motor. So i would get a old crankshaft and press it
Apart and put it back together!
Thanks.
Reed. 

[OldSwartout]

Just check the seal by hand.  Twist it slightly and see if it moves back (feels "springy").  I've had old cranks with seals that you could easily twist and would spring right back into position and others where the seal was so hard you couldn't twist it at all. Somewhere in between is still OK, but you're using your own judgement.    My personal opinion is that if a seal has a just a little give in the rubber and has no play on the shaft it will still work.  Many small 2-strokes (including the BS350s) used a metal labyrinth seal that had a tiny bit of clearance over the shaft and worked fine. The first place a problem will show up is at starting and idle, it won't leak enough to affect higher speed unless the seal lip is breaking up.

The biggest problem with replacing a crank seal is re-aligning the two halves at 180 Deg. exactly. You can be off some if you use a dial indicator to set the timing BTDC for each cylinder individually, but if you're going to use the timing pin, it has to be darn close or the right side will be off.  I made a fixture that does the alignment, but you have to take the crank completely apart, not just the center.  I did one, just taking the center apart, by just scribing lines across the OD of the crankwheels before disassembly, then using straightedge to get them back in alignment as you press them back together.  Not really sure how accurate that was, though.  The center pin tends to gall when disassembling and reassembling also, so you may not be able to redo one if you get it wrong.

[reed]

Hi Karl
I have a crankshaft jig to re line the crankshaft webs i always do my own crankshaft etc.
So like i said get a old crankshaft and press it apart and get the feel of using a press etc
But not to use the crankshaft again just for fun.
Thanks.
Reed. 

[scrambler]

A bit overboard with the tires or just about right?

[ridered]

Scrambler
It's always nice to see people using their imagination to build bikes. Looks like yours is going to turn out nice. After I finish my GTR it will be my last original restoration as the cost for that type of work can get real expensive. My next project is going to be an old school Cafe style bike using my GB500 parts bike for the base. Good luck with your project and keep posting pics.
Mike

[scrambler]

Well I'm just hoping it works and I can drive it. If not I'll at least have a great conversation piece.

Those tires are 4x18 on the front and I think the rear is just a bit larger. I couldn't believe they fit. I had to get a bit creative to get the front wheel on.

Not sure these are the tires I will be running, I pulled them off a pile of old used tires I had. That could work to my advantage as they are hard and should hold ice screws better. I needed to get an idea of what was going to fit.

This should be interesting if nothing else.

[scrambler]

Still making some progress.



Probably need a larger rear sprocket. I dropped 2 teeth on the front sprocket. I just remembered I have a pretty large rear sprocket on a 350 GTR parts bike. Any chance I get lucky and that fits a 175/200 wheel?

[scrambler]

It lives.

[ColoStone]

Way cool Scrambler , soon we will see a clip of you passing the finish  line right ?

[scrambler]

Its finished, at least for now. No pretty paint yet. First race this Saturday.

Had to switch from the 175/200 front end to a 350 front end. Still using the 175 18" wheel. Only modification for the swap was to shorten the stem by about 1".

[scrambler]

Well I made it though in one piece.

Quite the experience I have to say. I had moderate success on my 40+ year old bike. To start the morning off I couldn't get my bike started. That bike started in 2 or 3 kicks EVERY time at home. I kept the bike in my heated shop, rolled it outside and started it. Well I guess its not a cold weather starter, I need to work on that. Finally got it started and went out for practice laps. Never had it out on the track and this was my first time. The bike was running great. I thought I was even doing pretty good. Studded tires were sticking to the ice like glue, it was a bit odd to have a cycle out there. We have the race meeting and it turns out I'm the only one in the 250cc and less cycle class. I tell them I still want to run so someone from the 250-450 class says they will run with me. My time comes to race and I end up fouling a spark plug at the starting line. They sympathize with me, let me change them, and run after a few other classes.

I make it off the starting line but not exactly how I would have liked but I get going. The other guy got a pretty good jump on me. I give it my all and I'm pretty much doing full throttle the whole time. Well I'm only in third gear but once you get going there is no shifting. You can't really shift into a higher gear in the straights and back down in the curves. There just isn't time. The straights are 400 feet long. Over all the track measures 800' x 500'. Shift foot has to be down on the ice to ice shoe around the corners. Front and rear brakes are functional but I never had to use them.

I was flying. (at least in my mind)

It was a total of five laps. I never did get passed. Maybe he was holding back. I was going to ask him but maybe I really didn't want to know. The last 2 laps my bike wasn't running as it should. Was starting to misfire when I would let of the gas to set up for the turn. Bike is still running pretty strong for the most part and I get to see the checkered flag. I finished the first motorcycle race of my life. As I exit off the track and ride back to my trailer I have a hard time keeping the bike running and then it actually dies a couple of times. I get it restarted each time and limp back to the trailer.

I let it sit a while and fire it back up. Seems to be running pretty good again. Even though there was only 2 bikes in my class, well actually just me, we are able to run again in the final. Each class runs twice. I finally decide to run again but it wasn't a good choice. My bike only made it a half lap before dying and not re-starting. I get a tow back to my trailer and start thinking.

One thing I know is wrong is that I have a leaky exhaust gasket on the left side. New gasket in there but its leaking. I think my main problem is my jetting. I think I'm running to rich once the bike gets warmed up. So it looks like I have some jetting changes to make this week. Hopefully I can get something figured out for next weekend......

No pictures unfortunately. My wife took a couple but I'm a small speck against the white snow, and she took them while she was in the warm car with the kids.

OK, I've rambled on long enough.

[scrambler]

I forgot to add that I did get quite a few comments on the bike. Most were about how good it sounded. It is quite loud and there was nothing else there that came even close to sounding like it.

[ridered]

Kevin
Great job, that has to be a blast ice racing. I have always wanted to try that out but living in the south it's pretty much an impossible dream. Looks like you need to build a 350 so you can run with the rest of the pack. You are representing the BS folks out there on the ice so get that bike running in tip top shape and go out and get the first place trophy. If you are as good a mechanic as you are in fabricating you should have no problem getting that trophy. The Cafe pic of the 750 Honda you sent me was very impressive.
Talk at ya later
Mike

[scrambler]

I'll be back on the ice next weekend. I'm doing some jetting changes that will hopefully help. I was running a 125 main and I guess it was a bit to rich. It seemed ok until the bike really got warmed up. Its hard to tune because I don't really have any place to try out my changes except on race day.