1981 GSX1100 Katana Based Project

[Shin-Ken 1074]

I always liked foam. Are they GrabOns?

Hi Rob, I have used Oxford Grab-Ons on other bikes however, these are Johar grips. I like the barrel profile and they hold up pretty well to use and UV exposure. I bought these a few years ago from a supplier in the States and wonder if they are still being made?


Johar grips by Max Mutarn, on Flickr

[Shin-Ken 1074]

Thats pretty cool Do you think it's possible to mould engine and front sprocket covers the same way? More layers of course, but it would save alot of weight.

Hi Lars, not being an Engineer I don't know what level of stress and heat a carbon engine case would need to deal with and the life-cycle of carbon as an engine component under continual stress so from the technical aspect perhaps someone else here has an answer to that question? The cost would be considerable, many thousands of US dollars and perhaps for a part with a limited life?

Front sprocket cover would be easy. For a basic carbon cover just make a flat carbon plate and use aluminium bolts and spacers. There are many versions of sprocket covers using aluminium plate and there could be a carbon version available somewhere?

I modified a stock sprocket cover because I had a spare cover and wanted to see how light I could make it. A carbon cover would be much lighter so maybe in future that could be an option for the project?

Cheers.

[Shin-Ken 1074]

Found my spare OEM 630 sprocket. I think it must be from a Leopard tank not a bike!

OEM 630 sprocket by Max Mutarn, on Flickr


Replaced it with this.


DW 520 sprocket by Max Mutarn, on Flickr

[Shin-Ken 1074]

did you remove weight from the clutch cover ?

Seeing how far you go to save weight, did you consider a billet clutch cover, or one with a window ?
Expensive stuff.

Hi Rijko,

I thought about billet cases/covers early in the project and discovered that most of them are heavier than stock parts, are very expensive and even if they were lighter they are beyond my budget for the project. For a lot less cost than billet parts buying titanium bolts and modifying parts will save more weight.

Used a stock clutch cover with Ti bolts.

Cheers.

[Shin-Ken 1074]

The OEM airbox and filter are being deleted and for now will use the OEM rubber carb intake boots because I have a set on the carbs.

Carb intake 1 by Max Mutarn, on Flickr

[Shin-Ken 1074]

The original plan was to use foam filters, a great product and does the job however, now there is a Plan B.


Carb intake 7 by Max Mutarn, on Flickr

[Shin-Ken 1074]

I wanted something lighter, more compact and a bit "Old School" in looks. Doesn't get more "Old School" than mesh screens. I couldn't find a screen to fit the intake boots in any of the usual auto suppliers I deal with so started to look elsewhere. Tea strainer does a similar job so off to the kitchen department at the local shop and found these. Got a few strange looks as I was measuring the strainers but in the end found a perfect size strainer in fine stainless mesh.


Carb intake 2 by Max Mutarn, on Flickr


Removed the strainer from the frame and used a hot glue gun to marry the screen to the boot.

Carb intake 5 by Max Mutarn, on Flickr


Carb intake 4 by Max Mutarn, on Flickr

Carb intake 6 by Max Mutarn, on Flickr


Exactly what I wanted. Only has to keep out birds, insects and childrens fingers. Not worried about ultra fine dust and engine wear, at my age I will be worn out before the engine is worn out from the occasional bit of dust it may ingest.


Foam v screen. Screen wins!


Foam filter 2 by Max Mutarn, on Flickr

[GRich]

Great project so far!

I saw the carbs were mentioned a couple couple ago, and it reminded me of my old GS450S. I replaced the stock carbs for ones from a 1st generation GS500 for pure performance gains, and was really surprised at the weight difference! I didn't have an accurate scale, but the GS450 carbs were easily a couple pounds heavier.

[Shin-Ken 1074]

The 1981 34 mm CV carbs are pretty heavy and parts availability and price are becoming an issue and I want to keep this ride for the next 20 years. Will be swapping them for 2004 GSX 750 carbs, lighter and all parts are still available.


1981 34mm CV

34 mm CV by Max Mutarn, on Flickr


2004 GSX 750 36mm CV, even with the throttle cable attached it is almost a kilo lighter.


2004 GSX 750 by Max Mutarn, on Flickr

[Blower]

Getting engine lighter:
- Hayabusa gen2 pistons
- EFE cylinder block sleeved with Bandit 1200 liners and bored to 81mm
- Titanium valve spring retainers
- Cylinder head porting
- Regrinded camshafts

After those modifications your engine is not only lighter, but more powerful = your bike feels lighter

[Shin-Ken 1074]

Getting engine lighter:
- Hayabusa gen2 pistons
- EFE cylinder block sleeved with Bandit 1200 liners and bored to 81mm
- Titanium valve spring retainers
- Cylinder head porting
- Regrinded camshafts

After those modifications your engine is not only lighter, but more powerful = your bike feels lighter

Very good mods for performance. Excluding the Ti retainers as they are a given to be lighter than OEM retainers. Did you weigh each OEM component before the mods and weigh the new parts to compare the weight difference, or did you weigh the complete engine before and after the mods to confirm the amount of weight reduction?

[Blower]

Very good mods for performance. Excluding the Ti retainers as they are a given to be lighter than OEM retainers. Did you weigh each OEM component before the mods and weigh the new parts to compare the weight difference, or did you weigh the complete engine before and after the mods to confirm the amount of weight reduction?

I never weighted cylinder block before and after, but weight difference was noticeable, as was with pistons.
The whole bike (1150 EFE) after all modifications and rebuild was fuel tank half full weighted in MOT slighltly under 200 kg.
RW hp gain was from original 92hp to 142hp.

[Shin-Ken 1074]

Shocks arrived today, well packed and with a detailed manual to assist with settings.



Shocks 1 by Max Mutarn, on Flickr


Shocks 2 by Max Mutarn, on Flickr

[Shin-Ken 1074]

Each Nitron is 711 grams lighter than the shocks they will replace!

Shocks 3 by Max Mutarn, on Flickr


Shock lower bolts by Max Mutarn, on Flickr


DW shock lower boltsIMG_3346 by Max Mutarn, on Flickr


Shock OEM top nut by Max Mutarn, on Flickr


DW shock top nut by Max Mutarn, on Flickr


Current shocks = 3,994 g
steel lower bolts = 164 g
steel top nut = 24 g

Nitron shocks = 2,572 g
Ti lower bolts = 108 g
Ally top nut = 12 g

End result is:

4,180 grams vs 2,692 grams.

1,488 gram reduction is O.K. with me.

[Diirk]

I'm thoroughly excited to see the end result, but at the same time I'm not in a hurry to see it either because I'm enjoying the process
Those Nitron shocks look the mutt's nuts btw.