Suzuki 2 Strokes

Hey,

It's great to see the site back up and running. Great job to those involved in capturing and archiving the old data and posts. Thanks !!!

Well, since my last post on the bike build, I got a lot accomplished and made it out to the AMA Norwalk Fall Nationals during October 10-12.

My GT750 made it past tech inspection and I made several passes. Here are a few pics of the GT750 (the way it looked that weekend). I continue to make modifications to further reduce weight. Between the front rotor/caliper and battery change, I saved 21 lbs. I am starting a serious effort converting the head to a "squish" design. I made 3 passes, each one slightly better than the prior with the best pass at 12.83 sec/104.3 mph. I know thats not fast but it was a great shake down run and I had a blasts.

Here are some pictures that were taken of all the two stroke bikes at Norwalk. I hope it is ok that I clipped it from the Kawasaki Board but these bikes are all awesome and should be seen. There is a wave of two stroke drag bikes making their way to Norwalk. Please click on "PLAY" to see all the bikes...

The first pic is me needing to lean out the carbs.

http://www.shutterfly.com/progal/slides ... 5c8&idx=20

....but I was there and went as fast as I could....

great bike Water......I have sent you a PM.

Muzza

In an ongoing effort to shave pounds off the bike, I found a replacement battery that I will try out. Its a 12V 3Ah. I need to experiment to a large degree and determine if I can get 2-3 full runs from this battery without degrading the output of the ignition.

Anyway, the weight is about 3 lbs and saves considerable weight compared to my existing YUASA 12V - 14Ah battery.

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You could probably save 5 pounds by getting those big slabs of metal called brake rotors off the front and putting GS rotors on there that are much thinner and full of slots. One front brake would do on a drag bike, or none.

Barry S. wrote:You could probably save 5 pounds by getting those big slabs of metal called brake rotors off the front and putting GS rotors on there that are much thinner and full of slots. One front brake would do on a drag bike, or none.

*Measure your run-off area first!

Barry,

I agree with you. I took one off after getting back from Norwalk and weighed it along with the caliper, hose and bolts. The weight reduction is 11.4 lbs. I am sending one rotor out to have it drilled and expect to get that rotor down to about 5 lbs. and run with one only.

There are lots of places I can pull weight from...

Buchanan has some suitable aluminum rims. I'll drop the front down to 18" and use an MTT-3210 front tire which weighs about 6 lbs. (v. 11 lbs for the Bridgestone BT-45). I'm not sure yet how much weight can be saved switching to the aluminum rim.

There's several lbs I can drop from the engine, I still have most of the starter clutch gearing etc left in there when I switched from points to MSD. I just ran out of time. The cylinder head bolts can save some weight when I cut them down. The cooling system can be reduced, the seat is bulky...etc.

The rear swing arm is no light weight either...and the rear rim needs to be replaced to allow a 5.5 x 18" slick. I might build the rear wheel up from a 1978 GS750 spoked hub and replace the rim through Buchanan again.

Kevin,

Great result for a first time run. The bike is looking great.

Other weight savings in no particular order:

Frame - It's very heavy. Contact Randy Illg at framecrafters.net for a light chrome moly frame

Swingarm: Incredibly heavy and not much use. Randy can make you a replacement at a reasonable price.

Starter clutch: can be reduced considerably as long as you aren't using the stock starter that is!

Starter motor, wiring and solenoid.

Front Disk: get a modern disk with aluminum carrier and almost any twin piston, sliding type caliper say SV650 or EX500. You will have great brakes that weigh very little.

Rear wheel: That one is probably very heavy. Spoked stock type wheel with fat rim would look great but isn't as light as a modern wheel. If you can use modern wheels in that class, I'd go with say GS500 or katana rear wheel.

Wheels (Both): Replace teh bearing spacer tubes with aluminum ones but make then .020" longer to allow for crush.

Axles: replace with Titanium if money is no object or get them drilled through from one end to the other. That goes for the swingarm spindle too.

That battery is a good start. We use small batteries on our road race bike and connect them with simple two pin connectors. After a run, pull the plug and plug in the charger using a matching 2 pin plug.

A single charge should last all day, but this way you are always sure that you have a full charge.

Forks: Billet triples could be lighter than stock and use an aluminum fork stem. It seems to me that stock forks are very heavy (thick walls) and a later model bike may have lighter forks - look at a GS500 for example- or even a 250 street bike or cut down a set of 125 motocross forks.

Crank: That could be lighter, but this is getting out of hand

You could dump the complete stock front legs and fit some from an 81 GS 850 into your triple trees. It uses the thinner and lighter GS slotted rotors and the calipers as well that mount behind the stancion legs that are also much lighter.
The front wheel/hub from the Buffalo can be reused and you should save at least 20 lbs with this retrofit.

You guys are giving me enough to keep me busy all winter....I love it. Theses are great mods. I'm going to tackle the wheels first. Drop the front down to an 18" aluminum rim. Dave helped me find a hub for the rear from a 1978 GS1000. Buchanan spokes has a 4.25" x 18" aluminum rim to accept either a Goodyear Eagle or Mickey Thompson slick.

Then, I'd like to finish removing and lightening the starter clutch assembly, switch to the 3Ah battery and make a new bracket and finish off a few small engine mods to increase the compression just a bit.

I'll start looking into the GS850 fork mod and see what I can find on ebay.
20 lbs is a fantastic reduction....and a needed one.

Thanks Richard for the web link to "framecrafters" I studied it closely. Some nice bikes in there and a couple of TR750's in the bunch. I wont be able to do a frame this year but if I sort a number of other things out, it might make sense for 2010. A lighter swingarm might be in the cards though.

Thanks guys. All this is really helpful.

Kevin

I'm really diggin' that bike.

Besides going thru the disassembly lighting the starter clutch is pretty easy , remove the three peened over screws on the face and you can remove all the guts from inside the clutch and then just screw it back together .. Dave

markj wrote:I'm really diggin' that bike.

Yep .. looks low and mean

Take the starter clutch and as Dave said, dump the contents, then machine it down so that all that's left are three mounting tabs and the hub.

Drill the living daylights out of the gear and bolt what's left of those two pieces together.

The one I modified, dropped just over 600 grams on just that part. That's a pound of steel you don't need to carry.