'77 710...ish

[unfocused]

...when the toys are put to bed.

 

[Guest]

Looking good...

A couple things to keep in mind when using late model upside down forks on our GS bikes:

1. Fork springs on late model GSXR forks tend to be too soft for installation on a GS. You'll likely need around 1.0 kg/mm springs to get it right. Check the Racetech website for recommendations on spring rate https://racetech.com/ChooseVehicle.aspx and factor in the weight difference between the GSXR and GS in your calculation.
2. Check your rake and trail to make sure the bike will be stable and handle decently with a calculator like this: https://www.rbracing-rsr.com/rakeandtrail.html Trail is very important and you don't want to go under about 3.8" of trail for stability. Given this is a dragbike, more trail is better to keep it stable in a straight line at speed.

 

[unfocused]

Thanks GS,

I'll put that info to good use

Not that close yet LOL

 

[unfocused]

Mocked up at shock height.

 

[unfocused]

Challenging build. As I am sure some of you are aware, you go backwards as fast as you go forwards.

Here I've finally added the rear brakes, centered the wheel in the swingarm, to check for center in the frame... only after this do I have a chance to work with the chain alignment... ugh

During this garage visit I also installed the front rotors and calipers. I've ordered an experiment off of flea bay since the '77 front master cylinder is large for the clip on's causing issues with my old school headlight. It'll be a $20 mistake if it fails. I'll look smart if it doesn't

No matter what, I'm keeping those off kilter, round dated mirrors!!!

 

[Guest]

Something that may be helpful...try using a laser level to check if the center of the rear wheel is aligned with the center of the backbone of the frame. It's a lot easier and more accurate than using string.

 

[unfocused]

Ok, clicking wrong buttons... duh huh.

Took some time to start the engine. She runs, and well I might add. Lucky purchase !!!
Front brakes a fully functioning in the garage. Road test eventually.
Working with the headlight/front signals/wiring.
Fixed side stand... it's short. Shud-up!!!
That jeep needs a heater core.
Brought home welder, lazer level, and enough parts to hopefully at least find first gear and some tire spin :lol:

 

[unfocused]

I will be doing this over the long weekend LOL.
Among other things. A bunch of parts and time

Something that may be helpful...try using a laser level to check if the center of the rear wheel is aligned with the center of the backbone of the frame. It's a lot easier and more accurate than using string.

 

[unfocused]

During my time fixing everything I own, twice

... I was coerced into this... ugh

 

[Chuck78]

Confusing title at first, I kept thinking of what size GS650 piston would make 710cc, or what you could do to destroke a 750!
Then I saw the clutch cover linkage... Then the 710 started making sense! Not quite as talked about as the 7/11 swaps... A hyphen or backslash would make 710 (7-10 or 7/10) a lot more self explanatory!

I think you're going to be searching for shock springs for a while, but you may want to look into ATV and snowmobile shocks. Something of a laid down angle on one of those heavier machines could be closer to your range needed? Then you'll need different valving as well vs standard bike valving... There's likely going to be a lot of trial and error involved unless you enlist someone like Racetech to plug everything into their computer formula for a valving answer, or if you know someone with a shock dyno and you find some online calculator tool that gives you valving/damping rate targets based on suspension geometry...

Personally I would shorten that swingarm A LOT, to maybe 2.5" or 3" longer than stock if I was only looking for higher hp straight line performance.
Are you going with a 16v 1100E clutch basket? Or custom making a H.D. backing plate for the 1000 clutch basket?

Suzuki Performance Spares sell a spacer kit for the clutch cover to be able to run an 1100E clutch basket without loosing any clutch discs (as the basket has to be machined down to fit in a 1000 otherwise).
Welded crank will be VERY necessary, from the rear tire choices alone... A lot more traction than a 79 GS1000 had available back then, & hard use/abuse could twist a crank on those even!

What pistons? MTC had some bargains on some old school 74mm GS1000/1100G pistons a year or so ago. They are pretty old school though, NOS, heavier than a modern Wiseco or JE by a fair bit.
Would require 1100G cylinders, 1000 base gasket trimmed, block decked a fair bit (.020"?)

What carbs? Can't make out in the pics. Sticking with the small port head?

Best of luck.

 

[unfocused]

Confusing title at first, I kept thinking of what size GS650 piston would make 710cc, or what you could do to destroke a 750!
Then I saw the clutch cover linkage... Then the 710 started making sense! Not quite as talked about as the 7/11 swaps... A hyphen or backslash would make 710 (7-10 or 7/10) a lot more self explanatory!

​You're absolutely correct. I take full responsibility for this snafu... This build wasn't intended but since the 750cc ripped #1-2 cam cover out of the head I purchased another cylinder head. While waiting on parts a 1000cc mill showed up... and then the 2002 GSXR 750 called my name. So here we are !!!

I think you're going to be searching for shock springs for a while, but you may want to look into ATV and snowmobile shocks. Something of a laid down angle on one of those heavier machines could be closer to your range needed? Then you'll need different valving as well vs standard bike valving... There's likely going to be a lot of trial and error involved unless you enlist someone like Racetech to plug everything into their computer formula for a valving answer, or if you know someone with a shock dyno and you find some online calculator tool that gives you valving/damping rate targets based on suspension geometry...

I'm going to keep it old school and build my own with what I have. No fun in paying someone to do something that I need to learn about if I am going to be street racing and cruising the First Coast. When I want to dip into the 8's, then I'll talk to a shock specialist. I do however have access to a LSR holder that currently goes around in squiggly circles... on a Triton!!!

Personally I would shorten that swingarm A LOT, to maybe 2.5" or 3" longer than stock if I was only looking for higher hp straight line performance.
Are you going with a 16v 1100E clutch basket? Or custom making a H.D. backing plate for the 1000 clutch basket?

This swingarm gives me a range of adjustment from 3-6". I am NOT looking to turn corners as I have a BWM R1100 for this.
I'll look into the clutch basket. Not going that quick... yet.

Suzuki Performance Spares sell a spacer kit for the clutch cover to be able to run an 1100E clutch basket without loosing any clutch discs (as the basket has to be machined down to fit in a 1000 otherwise).

IIRC MRE sells a cover that orients the clutch cable to run down the right side.

Welded crank will be VERY necessary, from the rear tire choices alone... A lot more traction than a 79 GS1000 had available back then, & hard use/abuse could twist a crank on those even!

I've looked into this and I'm sure it's in my future...

What pistons? MTC had some bargains on some old school 74mm GS1000/1100G pistons a year or so ago. They are pretty old school though, NOS, heavier than a modern Wiseco or JE by a fair bit.
Would require 1100G cylinders, 1000 base gasket trimmed, block decked a fair bit (.020"?)

Stock.

What carbs? Can't make out in the pics. Sticking with the small port head?

Jetted 26's for now.

Best of luck.

Thanks

As this is the initial assembly, engine wise everything is stock except for the jetted carbs, Dyna S and V&H header into some $15 fleabay muffler that actually sounds pretty good. Deeper tone. I'll play with the gearing, learn about spring rates, rebound and more all while having some fun. Then after the thrill wears off I'll start adding duration and lift, pistons and more.

 

[unfocused]

Looking good...

A couple things to keep in mind when using late model upside down forks on our GS bikes:

1. Fork springs on late model GSXR forks tend to be too soft for installation on a GS. You'll likely need around 1.0 kg/mm springs to get it right. Check the Racetech website for recommendations on spring rate https://racetech.com/ChooseVehicle.aspx and factor in the weight difference between the GSXR and GS in your calculation.

I see what you mean about soft. Under normal suspension sag, I had 1.5". After further research and understanding I was able to adjust pre-load enough to keep sag at about 20mm-ish but this just about maxes out pre-load. Bike is running/driving and the front feels decent. I have let loose some part throttle hole shots but since the swing arm/suspension isn't finished squat/weight transfer is still up in the air. Although she comes out of the hole pretty good.

1. Check your rake and trail to make sure the bike will be stable and handle decently with a calculator like this: https://www.rbracing-rsr.com/rakeandtrail.html Trail is very important and you don't want to go under about 3.8" of trail for stability. Given this is a dragbike, more trail is better to keep it stable in a straight line at speed.

As the bike sits right now ( no rear suspension ) we're pretty close. This is something I have watched during my build. I have ridden her and in short burst of up to about 35-50 mph she tracks well. At about 30 mph I can let go of the bars and feel comfortable. Will check back on this after finalizing the rear setup.

Thanks

 

[unfocused]

As of Dec. 3rd 2019

She runs.
She drives.
Signals work. Well the fronts are getting some odd feedback. But they still work, without the engine running
Horns not installed yet so listen for the 9mm
Funny how the original charging system not only works but charges at 13.8 volts.
Simple hole shots have elicited large smiles.
A mild burnout (can be seen on Instagram under unfocused_adventure) sent me to Cycle Gear for some Bridgestones LOL
Sounds well, looks good.
Still needs foot pegs, rear suspension and rear brakes.

Knee surgery in two weeks, down for two weeks very little will be done after this weekend until the turn of the New Year !!!

 

[unfocused]

Another one...

 

[unfocused]

... and it starts LOL

 

[Guest]

Another one...

View attachment 59689

Looking good man! That GS1000 engine sounds healthy!

 

[unfocused]

Looking good man! That GS1000 engine sounds healthy!

Thank You.

I believe the exhaust setup helps. As you are, I am impressed with the sound.
I've managed to take her around the block and I'm very thankful for the deep tone!!!

 

[unfocused]

Still recovering from a nasty knee surgery.
But got this far.. anyone going to Eustis, FL this Saturday?
See it there.

 

[unfocused]

Thought I'd add a picture of the Norton that's also been occupying my time during recovery.

Shameless I know LOL...

 

[unfocused]

Made it to the show today. Had a good time chatting with everyone and met some wonderful people.

Also found this seat pan that looks fantastic.