GT750 Drag Bike

[water cooled]

....Dave
Working down my list of mods to get ready for Spring. Some are for show and some for GO....!

Rear Sprocket change
Install Data Logger EGT, RPM etc.
Move Coils under tank
Relocate Rear Pipe Mounts
Paint Frame
Add Steering Stabilizer
New Tank and Seat Paint
Move Ignition ON/OFF Switch
Add Remote Record for Logger
Keep working out at Gym

[water cooled]

It bothered me that I had a 76 tank on a 74 bike. For a long time, I wanted to straighten that out. So I got a decent 74 tank on ebay and started the process of cleaning it up. I bought the POR-15 kit to restore the inside of the tank. I've tried the KREEM kits but I liked POR-15 better. I think it was $35 and comes with everything you need (except patience) to completely restore the inside of the tank. This particular tank was pretty rough on the inside. http://compare.ebay.com/like/1209375918 ... s&var=sbar" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

Then, I bought Valspar Primer and Paint, and Dupont Clear Coat. Since I am not a painter and have no equipment, I also found a Paint Spray applicator from PREVAL. I thought it was much better than rattle cans and only cost $6. So I bought a couple of them.



Primed, Painted, Decals applied and then 4 coats of clear. New gas cap and secured the SUZUKI tank emblems with 3M Plastic Emblem Adhesive.



I dont think I should give up my day job....but for my first real attempt at painting, I think its ok for what it is. Last year, one of the racers decided to sell some of their equipment. I was very interested in the Data Logger and even wrote about it a few pages back. Anyway, we struck a deal. I had an old PC in my closet. I dusted it off and figured out how to get it working properly again. Then, loaded the RPM Performance Software, ran a bench test and found a spot on the bike where it would fit. Unfortunately, the coils were there and will have to move under the tank. The logger is small and very lightweight. It has 3 EGT probes, wires directly into the MSD ignition for crank rpms, has a "C" ring for clutch rpms and has an accelerometer to measure the launch. The logger will record about 30 second per event and will initiate off a signal once the engine rpms rise above 5000. should be able to fine-tune shift points and compare engine rpms to clutch rpms to see how much the clutch is slipping and when.





The frame will go off to welding and sandblast next week and then painting will start. The wheelie bars will get done at the same time and finally match. The wheelie bar supports were moved to add stiffness and the rear sprocket went from 50T to 52T.

I added some new switches to the handle bars...one for the ignition ON/OFF and one for the remote RECORD for the logger. All in all, I hope these changes will be enough for some additional improvement and also make the bike look a little more professional. Its time.

[Suzukidave]

Nice addons and a GoPro also

[tz375]

Datalogger looks serious for sure, and that L/M tank looks much nicer than an A or B. Measuring clutch slip is getting pretty sophisticated.

Mine is a 76 (A) and I used an older tank because it looks nicer.

Nice paint job too.

[water cooled]

Here are some pictures from the 1st SE race at Indy last month.

[water cooled]

[D&D CHASSIS]

Any improvements since Indy? Did you get the bog sorted?

[water cooled]

Still working on tire pressure, burnout box procedure and launch to minimize time on the 2-step to eliminate the bog. Im making progress, but slowly. The change to MT seems like the biggest part of the problem. Here is a video clip from Sunday testing.

http://www.youtube.com/watch?v=ULMw8JyvXTA" onclick="window.open(this.href);return false;

[tz375]

It's hard to tell from here but it almost seems to want slightly more time on the clutch to keep the revs up just as it bites.

[water cooled]

....any ideas on a quality source for springs that match the GT and GS clutch?

[old racer]

I used a extra washer under the bolts,
Worked for me.

[tz375]

Kevin, I was looking at http://www.supereliminator.com/" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false; records and classes and it's obvious that a GT has a significant weight advantage against say an H2 from brand K. Even without radiator and associated hardware, a GT is probably 70 pounds heavier than an equivalent H2.

There's an old rule of thumb that 7 pounds is equivalent to 1hp in terms of power to weight. It's close enough for this theory at least. So if a GT weighs 70 pounds more than an H2, it needs to make 10 more HP than the H2 to come close on performance.

That is always possible, but not necessarily easy. It occurs to me that there are two options to get on a level playing field. One is to increase bore size to 71.5mm for 771cc or plate the bores and take them back to 70mm (738cc) and use the FF classification.

It's worth talking to Boretech in OH or Millennium in WI to see how feasible that is. I suspect that with a set of stock bore Wossner pistons and carbide bore, you would dip under 10.0 and set a record that will stand until you next decide to break it. We could probably take over the FF class with a few stock bore bikes.

Wossners are available in a stock GT bore, and I see a set in my future once I learn how to ride this fool thing.

The only reason this came to me is that my bores look scored and if I can get the iron bores plated and get decent stock 70mm sized pistons, I'd rather do that and avoid boring it out and moving up a class. I have a set of 72 (J) barrels that may be in better condition, but then I have to port them first. But I have to get more HP out of this combo anyway, so maybe it's not such a big deal.

In your case, you could set the FF/M-HH record and then alter the frame and get the FF/A-HH record

Just a thought.

[water cooled]

R,
You're on the money with the power to weight ratio and difference between GT and H2. There are subclasses that allow a complete aftermarket or custom frame, front end and wheelie bars that would drop the GT down to about 325 lbs. but wouldnt work for "Modified" which requires the stock frame cradle.

Millennium Technologies is a sponsor of S/E. I did contact them last year and consider bringing the bore back down. But that decision is all about chasing records and takes me a little further away from my goal of chasing the 10 second barrier. The GT750 "9 second club" is pretty exclusive. Only Miller/Fortino 9.39 and John Davies 9.9 have joined that club and I want in.

BTW, when you mentioned scoring of your cylinders, if lines going up and down the bore are present, that can easily be taken care of with a ball hone and drill. 3 plunges on each hole and wipe it clean....then a new set of rings. Break the new rings in and go back to your normal 2-stroke oil. Think about running a little premix with the oil pump.

[tz375]

Yep, I need to pull the top end and see how bad they really are. It may clean up Ok with a hone. For the moment, I'm going to ignore it. The last run on Sunday was the fastest with way rich mixtures and over 100 in the shade, so for now power is less of an issue than technique. I do not want to pull the head until I have the time to get things machined and slip in a spacer plate etc.

I'll do all that if someone steals the FF/S-HH record back Until then I'll work on technique to get the ET down.

I agree with the record versus 9 second club logic, but I think that a plated bore and Wossners will probably make more power than o/S stock cast lumps.

BTW I watched the video of my launch and I'm sure that my truck gets off the line faster than I was managing on the GT - some scope for improvement there for sure.

[water cooled]

...when are you going to post some pictures? Ive got a couple of your bike but didnt want to post them without permission. Let me know if its ok.