1981 gs750 (gs750e) Retro Racer project

[Buffalo Bill]

Can't answer about the Kerker, but looking good.
That block of foam seat reminds me of how I'd do the seat of a vintage racer. The AHRMA rules require using the OEM seat pan. For track racing a firm seat is much preferred for moving side to side and feeling the suspension reacting to the road. I'd wanna shape closed cell foam like that over the seat pan.
Too hard for use on public roads however.

[LarsKroghStea]

Is it possible that these are original (or repro) rubber intake boots that have hardened and shrinked over time? Watch the video with sound

Boots by Lars Krogh-Stea, on Flickr

[2BRacing]

Yes, the original boots shrink and harden like that. On my 850, those boots shrunk so much that they just fell through the openings in the airbox.

New boots fitted perfectly again!

[Buffalo Bill]

Is it possible that these are original (or repro) rubber intake boots that have hardened and shrinked over time? Watch the video with sound

Boots by Lars Krogh-Stea, on Flickr

UNGH!!!…I'm happy mine are still working well after 37 years.

[LarsKroghStea]

UNGH!!!…I'm happy mine are still working well after 37 years.

I couldn't see the part numbers on the old ones, so they could be repros. I ordered new genuine Suzuki parts, and if they too last me 37 years I'm most likely done riding bikes

[LarsKroghStea]

Today I mounted the rest of the parts needed to take it for a real test run.


Choke; I'll find a better better place to mount it when the tank is on.
2019-07-06_11-11-16 by Lars Krogh-Stea, on Flickr


2019-07-06_11-11-06 by Lars Krogh-Stea, on Flickr


Made the seat a little more comfortable


2019-07-06_11-10-50 by Lars Krogh-Stea, on Flickr


Ready for tuning


2019-07-06_11-10-06 by Lars Krogh-Stea, on Flickr



2019-07-06_11-09-51 by Lars Krogh-Stea, on Flickr

Hooked up a Gopro on the bike and had a camera in a car behind me. The carbs need syncing and mid range tuning, but I'll leave that for later. I'm hoping to ride it home next week. Watch the movie till the end for a couple of pictures of the bike with tank and seat.

2019-07-06_11-09-29 by Lars Krogh-Stea, on Flickr

[LarsKroghStea]

While I'm waiting for the next trip to the garage, I've ordered some new tools. I want to use safety-wire on the rear sprocket and the caliperbolts, maybe other things too. I ordered drill guides for both nuts and bolts from Ebay. Tested it today, and it worked great. Didn't drill all the way through because I only had a hand drill and I didn't want to waste the drill bit (hard to keep straight when it breaks through). I'm waiting till I can mount it in the pillar drill so it'll stay in place and not break the drillbit. Here's the halfdrilled nut and the tools:


2019-07-15_10-24-38 by Lars Krogh-Stea, on Flickr


2019-07-15_10-24-47 by Lars Krogh-Stea, on Flickr


2019-07-15_10-24-27 by Lars Krogh-Stea, on Flickr


Also got som JIS screwdrivers for those dot-marked japanese screwheads:


2019-07-15_10-25-27 by Lars Krogh-Stea, on Flickr

[LarsKroghStea]

Hard to see, but somewhere inside all this spaghetti is my M-unit. There wasn't much room left after mounting the rear master and air-filter.


2019-07-15_11-53-49 by Lars Krogh-Stea, on Flickr


The suloution I believe is to make a tray for it under the tank. Easiest way seems to be to bend and pop-rivet a box and put it between the tubes, over the plenum-box. It's a good location too because most of the wires goes to the front. I'll make some kind of quick-lock device so I can pop off the tank when I need access to the M-unit (last picture). I've also mounted a quick-release fuel line coupler with dual ball-valves, so the tank is easily removable.


2019-07-15_10-25-50 by Lars Krogh-Stea, on Flickr


M-unit passering 2 by Lars Krogh-Stea, on Flickr


kawasaki_tankpinBK_650x370 by Lars Krogh-Stea, on Flickr

[LarsKroghStea]

These came today At last I have everything I need to drive it home.

2019-07-15_10-24-17 by Lars Krogh-Stea, on Flickr

2019-07-15_10-24-03 by Lars Krogh-Stea, on Flickr

[LarsKroghStea]

This is my plan for the speedometer signal pickup. I've cut out the bottom of a speedometer and removed the magnet. I'll make a disc from plastic and fasten the magnet in it. Then I'll mount the reed switch in the base plate. It would be cool if I can get it to fit inside the headlight, that would give a cool analog look to a digital solution.


IMG_20190720_150324 by Lars Krogh-Stea, on Flickr

[LarsKroghStea]

Mounted an automatic main fuse with release and reset function. Nice to have an easy way to disconnect all power (exept starter).


IMG_20190720_165537 by Lars Krogh-Stea, on Flickr


IMG_20190720_165455 by Lars Krogh-Stea, on Flickr

[LarsKroghStea]

The original petcock had a drainchamber with an extra fuelfilter in the lower end. With it mounted it was impossible to get the tank in position because the petcock hit the top of the carburetor. I ordered another without the bottom chamber and it fit perfectly.


Original:
cx500-petcock by Lars Krogh-Stea, on Flickr


New:
IMG_20190720_173327 by Lars Krogh-Stea, on Flickr

[John Kat]

Hi Larsh,
Where do you get the tubing to hide the electric cables from?
I was also considering using a Motogadget m-unit on my XR 41 replica but unsure it would reduce the amount of cabling...
To me the best position would be inside the fairing as that's where most of the wires are located?

[LarsKroghStea]

Hi Larsh,
Where do you get the tubing to hide the electric cables from?
I was also considering using a Motogadget m-unit on my XR 41 replica but unsure it would reduce the amount of cabling...
To me the best position would be inside the fairing as that's where most of the wires are located?

The braided nylon tubings are from ebay: https://www.ebay.com/itm/10M-long-6m...UAAOSwRjxcC6UJ
But the also sell them locally at the tools/carpart outlet.

They have them in different diameters and lengths. I combine them mostly with shrinktube, but I also have a roll of cloth harness/loom-tape for very short runs of cable:

https://www.ebay.com/itm/3-Rolls-Adhesive-Cloth-Tape-Electrical-Wiring-Harness-Loom-Wire-Cable-Felt-Tape/372581694802?epid=9028488887&hash=item56bf997d52:g:4s8AAOSwDmxcTtbc

There are some wiring involved with the m-unit too, but it is much more structured. One side is for switches and the other side is for outputs. The unit checks for shorts and voltage-leaks, so any faults down the road should be easy to find. Another thing I like about it is that the control side doesn't carry any current. That means no voltage drop through the handlebar switches. Also, if one switch should fail I can switch the output on/off through my cell phone. And.. I like electronic gadgets

For the XR 41 I guess behind or under the headlight bucket would be a good place to put it

[LarsKroghStea]

Made the tray for the m-unit and ignition today. Will drill holes for cables and for strips to fasten it later.

2019-07-26_09-39-00 by Lars Krogh-Stea, on Flickr

2019-07-26_09-40-23 by Lars Krogh-Stea, on Flickr