GS1000G mods- big bore and fuel injection

[GS1000G Shopper]

Thanks for the combustion chamber info. As for the picture/page/post, why bring up an issue that has been resolved? I'm going to houseclean this whole thread once the project is complete and use the first post as a table of contents so members do not need to wade through irrelevant research material.

 

[GS1000G Shopper]

The GSX-G throttle cables are too short by a couple of inches. I've been trying to find lengths for other models, but this is apparently classified information. Most places list the length as "standard". The GSX-G housing is 42", and I estimate another 2~3" would do.

I see Motion-Pro makes (or perhaps made) an extended length (+5") push/pull cable set for sport bikes, and the base number (021-281) fit an older GSXR1100. The only place I see that lists this is Sudco.com. The extended sets are $63, and I have no idea if they are long enough.

One other possibility is a set from the VL800 wannabe Harley model (I was surprised I didn't see one in their new ad but then again they all look alike to me ). I found M-P makes extended cables for these in +6 and +7 lengths. Apparently, the HD madness hits these owners as well, as one thread showed how to put 14" Ape Hangers on one. I'll not link it out of consideration for those with queasy stomachs. That particular project used a universal cable from England. The used VL800 cables I've seen on eBay look like they have the same ends, so if the length is right, these should work.

Solution: eBay seller ID steelescycle made a set for me for $25/cable. I ended up only using one. You need to have about 4.5" sticking out to hook up to the throttle bodies. The housing length I got was 47.5" + 4.25" for cable (51.75" overall), and the housings were too long (too long is workable, too short is not). A 44~45" housing (48.5~49.5" overall) would work fine. The housings must have 90 degree fittings at each end. I used a set from a 1992 GSX1100G as a template, they are almost long enough.

The GS1000G stem mounted choke cable will barely fit onto the fast idle cam on the GSXR throttle bodies.

UPDATE
I've decided to use the center linkage solution that is linked in the table of contents post. I was able to re-use the longer cable OK, so the shorter one would likely work but was not tested.

 

[salty_monk]

You can get custom cables made up at somewhere like Speedy cables.... There was someone who linked a company they used on here. Can't find the info offhand but a search might bring it up.

 

[first timer]

Try a local chopper or old time bike shop in your area, those are the places by me that do custom cables.

 

[Guest]

Airport! find a shop that does small aircraft. They use lots of cables and could make one what ever length and fittings you want.

 

[salty_monk]

http://www.motionpro.com/motorcycle/custom/

Doesn't seem much worse in price than a normal set & MP is a decent company... Pretty much the first hit on Google.

 

[1948man]

http://www.goldwingcycleparts.com/ecom/category/529/11/

Someone speculated these folks might do custom lengths.

 

[GS1000G Shopper]

http://www.motionpro.com/motorcycle/custom/

Doesn't seem much worse in price than a normal set & MP is a decent company... Pretty much the first hit on Google.

Looks like that will be the best idea to date. I can send in the GSX-G cables.

Heard back from an eBay seller as to the VL800 cables:
from tip to tip they are 42 1/4" and 42 5/8"

This is the same length as the GSX-G cables, but the +6" ones for the VL800 would work.

 

[GS1000G Shopper]

Photo updates-
Front fender repainting. Not a perfect match by any stretch, but not bad for about $10 of paint. The color is Krylon Burgundy. It was sprayed, allowed to dry, polished, then sanded with 1200 grit. After 4 coats, it was top coated with some polyurethane.

New battery cable, 6 gauge from McMaster.com:

More pics to follow in the next post.

 

[GS1000G Shopper]

Throttle bodies in place, they were a tight fit and I ended up using a nylon strap to install them (a trick learned from fighting V65 Sabre carbs). Some pics show the setup with the stock airbox, and others with pods. I think there will be room to mount the electric fuel pump in front of the stock airbox.

This pic shows the 45mm hose that goes into the stock airbox:

Pods:

 

[GS1000G Shopper]

I also got a couple of cables custom made for $25 each from seller steelescycle on eBay. Total was about $59 shipped. I went with 47.5" housings (+5.5 on the GSX-G) and 51.75" cables. I should have them in a week or so and will post here as to how they fit.

EDIT
After using the center linkage, I found both the stock throttle and choke cables worked OK.

 

[GS1000G Shopper]

Preliminary wiring test is a go, no blown fuses, and so far:

• Low beam
• High beam
• High beam flash
• Left & right rear turn signals (Windjammer is still off)
• Hazard flashers

The red harness wire that goes to the ignition switch is too small in my opinion- it was warm when I was holding it. It looks like 18 gauge or so. I'd like to replace it with some high quality automotive wire of 16~14 gauge or so.

The main thing I'm waiting for now is the fuel pump, I got a shipment notice a couple of days ago. The plan at this point is to mount it in a finned aluminum sleeve. This is a "Professional Products" pump mount for a 45mm or so external pump, so I'll split it and bolt it together to accept the 52mm Bosch pump.

Preliminary test fitting with the airbox in place looks like a go. I can route the hose from the petcock to the pre-filter, then to the pump on the right side. From the pump, to the post-filter, which should be easily accessible on the left side. If I find the right filter, I can use the stock GSXR600 fuel hose, as it has a 90 degree fitting on each end.

I also mounted the fuel pressure fittings except for the gauge, I'll need it to test the pump when it gets here.

 

[GS1000G Shopper]

The fuel pump arrived with today's mail, and it looks good. Testing showed about .8 amps free flow, and at 50 PSI it drew 4.25 amps. Using PWM I doubt I'll draw much power constantly.

I cut the heat sink and flattened the sides so they fit the 52mm pump better. Using some 5mm socket head bolts, I placed an 8mm nut between the heat sink halves and this allowed enough tension to hold the pump.

The pictures I took will greatly help show how this works.

 

[GS1000G Shopper]

The longer throttle cables arrived today and I really overestimated the length. It looks like I underestimated the inner cable by about 1/4". When I hook both up, there is no slack, and the throttle hangs. Looking the setup over, I have to wonder why two cables are used here- push/pull. I removed one and made it a pull-only setup and it seems to work fine. I'm sure there is a reason for two cables, but I'm not sure what it is. I may rig up a return spring in the other cable opening on the throttle body to make sure they close all the way.

I'm still figuring out how to mount the fuel pump, and have to mod the heat sink a little due to a raised ridge on the pump body.

 

[49er]

Push/Pull cables are designed as a safeguard against icing on manual slide carbs when riding in winter conditions. Riders who have tried single cables, usually convert back to duals once they survive their first icing up experience.

 

[GS1000G Shopper]

I can say icing won't be an issue here in FL, plus the bike has throttle bodies w/o slides. The bike survived 30+ years with a single cable, so I think it will be OK. I am going to locate a spring on the other cable opening so the TB will be 100% closed when the throttle is closed.

 

[coombehouse]

I can say icing won't be an issue here in FL, plus the bike has throttle bodies w/o slides. The bike survived 30+ years with a single cable, so I think it will be OK. I am going to locate a spring on the other cable opening so the TB will be 100% closed when the throttle is closed.

I have been following this thread with interest as I am doing the same mod on my gs1100 katana. I guess I am a little further ahead than you as I have fitted dual cables, got the pump mounted & sorted the temperature sensors. I am rapidly running out of space though. Just need to sort the fuel feed & return & the regulator. I have also binned the Suzuki ignition to give me the ability to retard the ignition when starting as I have had issues in the past.
I have used dual cable as I figured Suzuki used them on the Gsxr for a reason. I have also mounted the bodies upside down with the throttle cables coming in from underneath. The linkage is also now moved from the end to the centre of the body assembly. Seems to work fine.
Good luck with your mods.
Nick

 

[GS1000G Shopper]

I'd like to see a pic of your TB setup, off the top of my head I'm not sure how the linkage could be moved to the center on the GSXR600 TB units- it is attached to the end body.

I made a bracket last night to:
1. Keep the clutch cable away from the linkage, and
2. Mount a return spring.

I'm going to shop at the hardware store for the proper spring, and may have the cable guy make me a shorter cable- I think the extra bend is adding to the overall drag.

Today I'm going to try and cut a groove in the heat sink for the fuel pump so it will mount more evenly, then I can see about mounting it to the air box.

Here are some pics of the fuel pump & heat sink, as well as one of the Wix 33302 filter I plan to use.I had to lighten some of the pics due to poor lighting.

Wix filter:

Overall view of pump in heat sink (you can see the ridge where I want to notch the heat sink):

Since the heat sink was too small, I cut it lengthwise and flattened the curve using a hammer and my shop floor until it matched the 52mm pump. I added two 8 mm nuts where it bolts together. This provides ample friction to hold the pump.

Here's a view of the mounting flange:

 

[coombehouse]

Some pics for you.
I just swapped the outer body & one of the inner bodies to move the linkage.
Nick

 

[GS1000G Shopper]

Thanks. Looks like an interesting setup.

UPDATE
I am going to use the center linkage. The downside is the idle screw is difficult to reach, but the upside is a better linkage (pulling from center vs side) and the likely retention of the shorter throttle cable. The tab from the side TB was too short to connect to the linkage where the cable goes, so I made a modification. The key here is to have all 4 TBs synchronized and to be sure all are closed at idle. I welded a small 3/8" block to the TB that holds the center linkage (picture below). This allowed enough overlap for the next one to connect as it should.


The main drawback to a center linkage is that the idle screw will be hard to reach. To overcome that, I am looking at various remote cable type screws. I had one from a Honda ST1100, but the threads were too small (4mm). The Keihin TBs use a 5mm very fine (<.8) thread. I found a 15" remote cable for $5 shipped on eBay, but it was way too large at 3/8-24 thread. 5mm is slightly larger (.1970) than a #10 screw (.1900). I'm thinking a cable from another brand may work and have sent out some inquiries. So far I've found the one from a Kawasaki Ninja 250 is also 4mm.

I found a thread on the ST Owners Forum (registration required to view pics, I've attached the relevant one) that says the ST1300 idle cable on those are 5mm. If this fits/works, the Honda part number is 16029-MCS-003 and they call it a "SCREW SET, STOP". Partzilla sells it for $22.50 + shipping.

UPDATE
The part arrived and the 5mm thread is a different pitch. The part contains a new longer spring (too long) and a steel washer. I used a tap and rethreaded the linkage to 5mm x .08, which is the same as the ST1300 part. I had to cut off the unthreaded part of the cable end where it goes into the linkage. This made it the same length as the GSXR600 idle screw. I added some anti-seize to the threads, and reused the Suzuki spring with the ST1300 steel washer. Best of both worlds.

The cable is long enough that it runs to the left side of the bike by the fuel filter.

EDIT
After looking over the situation, I found I can turn the idle stop screw with a long flat blade screwdriver, so this part while not absolutely needed is a real convenience.