1100 Katana restomod with 1230 engine

[John Kat]

My 1100 Katana has been modified over the years and I'm now totally happy with the result.
The modifications were mostly related to installing a modern suspension with 17" wheels.
As we all know, the issue with the GS bikes is to keep enough ground clearance with modern forks that are typically quite short and with very little offset.
The components I use are Bandit 1200 forks with DL 1000 triples.
For the rear, the shocks have been extended to 350 mm eye to eye
Two issues however remained: the bike needs to be freshened up and the engine needs a rebuild as it consumes quite a bit of oil.
The engine itself is a GS 1150 ( 1135 cc) for which I ordered a 1229 Wiseco piston kit.
For these reasons, I decided to tear the bike apart for a complete rebuild.
Here it is today:

 

[Guest]

lol "I'm totally happy with the result" so "I decided to tear the bike apart.." love it. Us gs guys are a peculiar bunch. I look forward to the results!

 

[Guest]

Definitely keen to follow along here John! Love me a good Kat (re)build!

With the front end, were those literally bolt on upgrades or was any machining required?

 

[John Kat]

Definitely keen to follow along here John! Love me a good Kat (re)build!

With the front end, were those literally bolt on upgrades or was any machining required?

No machining whatsoever!
I thought I would have to provide some form of lock stops but in fact the lower fairing support does just that.
The stem of the DL 1000 looks very long but fits with no issue.
More details here:
https://www.thegsresources.com/_for...-1000-Vstrom-triple-on-1100-Katana&highlight=

 

[posplayr]

My 1100 Katana has been modified over the years and I'm now totally happy with the result.
The modifications were mostly related to installing a modern suspension with 17" wheels.
As we all know, the issue with the GS bikes is to keep enough ground clearance with modern forks that are typically quite short and with very little offset.
The components I use are Bandit 1200 forks with DL 1000 triples.
For the rear, the shocks have been extended to 350 mm eye to eye
Two issues however remained: the bike needs to be freshened up and the engine needs a rebuild as it consumes quite a bit of oil.
The engine itself is a GS 1150 ( 1135 cc) for which I ordered a 1229 Wiseco piston kit.
For these reasons, I decided to tear the bike apart for a complete rebuild.
Here it is today:


View attachment 60271

Since you are ripping it apart, i would plan on a little frame bracing as well. Katman used to do a minimum about down near the swing arm pivot.



I think C,D and E are big improvements for the street. No need for the rest.

 

[John Kat]

Since you are ripping it apart, i would plan on a little frame bracing as well. Katman used to do a minimum about down near the swing arm pivot.



I think C,D and E are big improvements for the street. No need for the rest.

I'm well aware of these modifications but have decided to keep the frame stock.
Two reasons for this: first I can get the bike back to OEM if required and second at my level of riding they are not required.
A few racers over here believe there is no improvement to be had?
I remember an article many years ago when a Honda HRC engineer stated that they had decreased the rigidity of the frame in some areas to make it easier to control the bike.
I also remember that I sold my Z 900 when the GS 750 came out as the roadholding was like night and day...
The question on my mind today is : should I go with the stock cams or use the Webcams #223 with .340 lift and 266? duration?

 

[posplayr]

I'm well aware of these modifications but have decided to keep the frame stock.
Two reasons for this: first I can get the bike back to OEM if required and second at my level of riding they are not required.
A few racers over here believe there is no improvement to be had?
I remember an article many years ago when a Honda HRC engineer stated that they had decreased the rigidity of the frame in some areas to make it easier to control the bike.
I also remember that I sold my Z 900 when the GS 750 came out as the roadholding was like night and day...
The question on my mind today is : should I go with the stock cams or use the Webcams #223 with .340 lift and 266? duration?

On my 831100ED I did all i could to make the stock equipment work (emulators, Ohlins in back, fork brace, Sport demons) and the bike rode very well up to about 70 mph. You had to be more gingerly after that.
After doing the 1166, ported head, 0.340's teh bike was a little scary even at 60 under acceleration.
After that i did the 1988 GSXR 18" wheels/forks/Bandit Swinger conversion with radials and the same uneasy feeling came in around 90 mph now. I would certainly go faster, just did not want to hit corners real hard.
The 17" wheels would have probably improved things, but i always felt a little hingey and this was corroborated by Rob Katman).

For that BB I would go for the 0.348's. The 0.340 are mild even for the 1166 but they have improved longevity due to reduce valve seat pressure.


For the street and back country roads I would also use a 4:2:1 is you can find it. Really helps remove the mid range flat spot typical of 4:1

 

[Guest]

Cool John thanks for pointing me in the direction of your DL/Bandit swap thread too, very interesting!

 

[John Kat]

On my 831100ED I did all i could to make the stock equipment work (emulators, Ohlins in back, fork brace, Sport demons) and the bike rode very well up to about 70 mph. You had to be more gingerly after that.
After doing the 1166, ported head, 0.340's teh bike was a little scary even at 60 under acceleration.
After that i did the 1988 GSXR 18" wheels/forks/Bandit Swinger conversion with radials and the same uneasy feeling came in around 90 mph now. I would certainly go faster, just did not want to hit corners real hard.
The 17" wheels would have probably improved things, but i always felt a little hingey and this was corroborated by Rob Katman).

For that BB I would go for the 0.348's. The 0.340 are mild even for the 1166 but they have improved longevity due to reduce valve seat pressure.


For the street and back country roads I would also use a 4:2:1 is you can find it. Really helps remove the mid range flat spot typical of 4:1

Very valuable inputs (as usual!).
Your experience with your bike reminds me of the issues I had with my GS 1000 ST.
Past a certain speed the bike felt also unstable with slow weaves building up...
After modifying it to GSXR 1st gen wheels and fork plus a GS 1100 swingarm it cured the issue.
The tires are Conti Road Attack 2CR.
I also noticed that the front fairing that's attached to the forks greatly contributes to the instability.
Coming back to the 1100 Kat, it's utterly stable and the "cartridge" type forks of the 1st gen 1200 Bandit surely play a great role.
As for the exhaust, I was lucky to pick up a Kerker 4 into 1 into 2 that works really fine while looking good at the same time.

 

[John Kat]

Cool John thanks for pointing me in the direction of your DL/Bandit swap thread too, very interesting!

Glad to help you out!
You need the 1st gen DL 1000 triples and the bearings from All Balls racing: https://www.allballsracing.com/index.php/forkconversion
PS: the reason it worked with Bandit legs is that the spacing is identical to the OEM Bandit triples.

 

[John Kat]

As mentionned elsewhere the bike came with an 1100 Cylinder head on a 1150 bottom end.
Luckily, I found a matching 1150 cylinder head that has been ported.
I noticed that the cams are different between the two models (R2 vs R1)
Luckily the design of the head puts the intakes at exactly the same place so there should be no problem to fit the air filter in the Katana frame.
That's cost conscious R&D at work!
Here's a picture of them both side by side:

 

[posplayr]

As mentionned elsewhere the bike came with an 1100 Cylinder head on a 1150 bottom end.
Luckily, I found a matching 1150 cylinder head that has been ported.
I noticed that the cams are different between the two models (R2 vs R1)
Luckily the design of the head puts the intakes at exactly the same place so there should be no problem to fit the air filter in the Katana frame.
That's cost conscious R&D at work!
Here's a picture of them both side by side:

View attachment 60300

How do you just happen to find a "cheap' ported 1150 head laying around? That would seem to be a rare bird unless there is a strong racing circuit by you.

 

[John Kat]

How do you just happen to find a "cheap' ported 1150 head laying around? That would seem to be a rare bird unless there is a strong racing circuit by you.

Haha, it wasn't exactly cheap but just across the channel from France, there is a small island that must have the most enthusiastic racers in the world!
I couldn't believe my luck when I saw the head for sale on ebay UK.
I didn't even try to negociate the price as I was so happy!

 

[posplayr]

Haha, it wasn't exactly cheap but just across the channel from France, there is a small island that must have the most enthusiastic racers in the world!
I couldn't believe my luck when I saw the head for sale on ebay UK.
I didn't even try to negociate the price as I was so happy!

Cheap GS thrills are great

 

[John Kat]

I have an issue with my OEM cams on my 1150 engine.
The camshafts came with separate cam gears and I'm concerned that they are the right type?
The intake gear is marked #451 and the exhaust #470.
Is that correct?

 

[John Kat]

I have an issue with my OEM cams on my 1150 engine.
The camshafts came with separate cam gears and I'm concerned that they are the right type?
The intake gear is marked #451 and the exhaust #470.
Is that correct?

View attachment 60373

I believe it's OK as I found the diagram to set the cams in a french technical manual.
Here it is for anyone interested:

 

[John Kat]

With the help of 2 friends, we got the engine out and the frame is now bare, ready for sandblasting.
The cylinder block should be rebored by tomorrow...

 

[John Kat]

I bumped into a new issue: the ECU on the bike is a GS 1100 unit that provides a fixed ignition timing while the 1150 engine requires an ECU with variable timing advance...
The PO obviously just banged the 1100 and 1150 pieces together without further thought!
Of course the OEM 1150 ECU appears to be unavailable?
I suppose I'll have to buy a Dyna 2000 ECU...

 

[steve murdoch]

With the help of 2 friends, we got the engine out and the frame is now bare, ready for sandblasting.
The cylinder block should be rebored by tomorrow...

View attachment 60394

Superhawk in the background?

 

[limeex2]

I'm well aware of these modifications but have decided to keep the frame stock.
Two reasons for this: first I can get the bike back to OEM if required and second at my level of riding they are not required.
A few racers over here believe there is no improvement to be had?
I remember an article many years ago when a Honda HRC engineer stated that they had decreased the rigidity of the frame in some areas to make it easier to control the bike.
I also remember that I sold my Z 900 when the GS 750 came out as the roadholding was like night and day...
The question on my mind today is : should I go with the stock cams or use the Webcams #223 with .340 lift and 266? duration?

I did the D & E modifications with no "X" braces with noticeable results. With a little fore thought it would be very easy to make side cover stays/mnts. I understand wanting to be able to go back to stock. As mentioned, every up grade to the bike will pronounce the "hinge in middle" effect. Emulators and high quaility rears help immensely in this issue and not having the bracing is a liitle more forgiving on our bodies. (good frame flex!) In Minnesota, as our roads are potholed filled junk, premium suspension is almost a must due my back and wrist issues. Modern Triumph's are good at this. This is a great/timely post for me as my health gets better.