Suzuki 2 Strokes

under seat fan fitted to aid cooling of the radiator.............



and my arse..............

hovercraft use smaller fans than that.....

But in this case, the old expression about blowing smoke up someone's ass makes prefect sense.

All joking aside, looking at that fan again, it says 80w which is a lot of power. It is also very large compared to say a GSXR or R1 or whatever. I certainly have not stopped to look at loo many modern bikes but the fans I have here are much smaller. I suspect that a smaller fan would be sufficient.

Another thing to think about is airflow, can air easily be ducted in and out of that space? It may require exhaust ducts to get the air flowing freely.

Either way, I am sure you will work it out.

On a different tack for a moment, are you keeping the electric starter? If not, that left side can be slimmed considerably. Use an electronic tacho and delete the cross shaft and drive gears and fit an electronic ignition on the end of the crank. On the right side it should be possible to fit a smaller inside out alternator and lose 3-4" on that side too. You would need to see if they make enough power at low revs though. Not much good if they are awesome at 12,000 and no power at say 3000. I suspect that any modern alternator would make more electrons at any revs than ours, but worth checking with Electrexworld or Rex's Seed shop or Rex Caunt. Or try the guys at BDK engineering. They do a bunch of light alternators and they make TR750 bits and might be interested in the project.

It may also be possible to place the ignition pickup and rotor on the right side and leave the left side flat.

Richard
cool air will be ducted from the nose of the fairing to the space shared by the carb intakes and the radiator. However this will, obviously, only work at speed. The water pump / tacho drive shaft has been deleted, along with both of the left side drive gears. I am also blocking the oil galleries to that side so the cover does not need to be oil tight. It may even be possible to shorten the crank too.The ignition will be fitted on the right side of the crank - it's a HPI self-generating system so it won't draw current from the small battery I am planning to fit that will power the fan, water pump and rev counter.
The starter motor has been binned to save the weight added by all those hose clips !

I had thought of Powerdynamo but it's output is very low IIRC. Is there a street HPI system or did you get the no charge race version?

garry55 wrote:under seat fan fitted to aid cooling of the radiator.............
and my arse..............

That sucks! Be careful that it doesn't or you'll have roasted nuts!

may put some heat-reflective foil on the seat base, Al...................

tz375 wrote:I had thought of Powerdynamo but it's output is very low IIRC. Is there a street HPI system or did you get the no charge race version?

there are several HPI ignition kits for the GT750 - the one I am using fits to the r/h side of the motor, which keeps that side nice and slim. It is a self-generating unit, so no charging facility. I will take a couple of pre-charged 12v batteries along and hope that 1 battery will cover the morning session of the track day, and another for the afternoon. And 1 spare, for if that fan proves to be too high a current draw.

80 watts is 6.5 amps. That'll soon flatten a small battery even if you have it on a stat. The start current would be probably x5 for a second or two every time it kicked in too.

If the airflow is good, on a track bike the fan may not be needed. Check out teh Britten and see how they arranged things. Just try not to get stuck on the grid for too long waiting to go out.

Alan H wrote:80 watts is 6.5 amps. That'll soon flatten a small battery even if you have it on a stat. The start current would be probably x5 for a second or two every time it kicked in too.

maybe need 6 batteries then - or 3 bigger ones?

Nice work is that the GS750 gear box ?

yes Dave

as well as the GS input shaft being longer, the clutch-side end is already plugged to prevent oil seepage. Just one small oil feed hole to block in the shaft itself. The clutch hub is away being machined to fit the larger diameter of the GS shaft.
Still have to machine the output shaft to get it to fit the GT750 casings though.

today I have been mostly cutting....................







and filing................................







not a lot to show for 4 hours of my life, but necessary all the same.....