Suzuki GS1000e/s/gs1100/gsx1100 project...

[steve murdoch]

Bike looks great, John.
I don't want to get too sidetracked on Bob's thread but did you any clearance issues with the carbs and the tank?
I have the same setup and had to massage the tank a bit and run a small rubber "guard".

 

[John Kat]

Yes Steve, the tank sides touch the top of the engine.
I'll open a new thread to show how I solved this issue not only for the 1135 engine but also for the GSXR 1059 in two different ways.

 

[bobtail84]

So, a little while back I mentioned that I was going to fit a wide band lambda and gauge to the bike which has been done. The reason for this was to set up the 33mm smoothbores and before I get into that this is the location of the sensor.



The 33's came with 140 mains with standard 17.5 pilots and the jet needle set on 5, this is the needle as high as it could be, the seller assured me the set up run perfectly on his bike...
As you can see from the main body of this thread I have a 1085 Wiseco pistons, ported inlet and exhaust, Pop Y cams and a Ti Racefit exhaust and it ran like a pig.

1st thing I did was drop the mains to 137 and drop the jet needle to position 1, it was better but choked up below 4000rpm. It also was very flat until the absolute top of the rev range which is no good.

To cut a very long process into a reasonable time frame, the changing of mains to 135 then 132.5 then finally 128.5 has given me a nice 1/2 to full throttle response and AFR reading.

There are stories that 33's won't idle properly then also transition between 1/4 and 1/2 throttle has a flat spot, well mine idle really nicely and pull from idle right up the range. But, it took time to get them to where I wanted them.

As we all know the 33's idle on the air screws, I set those up using colour tune and checked the AFR reading on the gauge, once this was stable I moved the jet needle up and down trying to get a smooth transition from closed throttle to 1/2 throttle. This area is controlled by the pilot jet and the AFR was leaning off so I changed the jets from 17.5 to 22.5, I was trying to reduce the height of the jet needle so the mid range was not to rich to early during transition between pilot and main. With the bigger pilots the idle to 1/4 throttle was massively improved also with the Jet needle in position 3 the transition between 1/4 to 3/4 and full throttle is also greatly improved. I will drop the jet needle down one more just to see if it's better or worse just to be sure I have tried everything.

Below is a picture of the AFR when the bike idling of the choke but not up to temp, Stoich is 14.7 but with these old bikes 13.8ish is fine for idle. I don't have a picture for obvious reasons but here in the UK they love a 50mph road and when the bike is cruising at 50 the AFR is hovering around 14.7 which is spot on. On WOT the AFR is up to 12.7 so that is also good enough for 45 year old carbs on a 53 year old bike.



Please also bare in mind that if you try what I have done wide band lambdas were developed for fuel injection so when used with carbs the reading will not be stable all the time, I have 4 33mm smoothbores that are older than my children and the readings are there or there about 95% of the time, don't fret if the gauge moves by a couple of points from time to time, compared to fuel injection carbs are basically 4 bucket pouring fuel into an 8 valve dinosaur, but a very nice dinosaur none the less.

 

[LarsKroghStea]

Hi, nice work

I see you have an oil temp gauge. May I ask what route you went to get the temperature reading?

 

[bobtail84]

Hi, nice work

I see you have an oil temp gauge. May I ask what route you went to get the temperature reading?

I bought a very cheap eBay oil temp gauge that came with it's own sensor, you will need to check the thread pitch as they are all slightly different to the Suzuki pitch. My bike was a 1000 S that had been re-framed using a GS1100 so the engine had the oil temp sensor next to the oil pressure switch but since I have now added an oil cooler the adapter has the space for a oil temp sensor, I used the sensor that came with the gauge but had to source an adapter from eBay to match the thread pitch and it all works very well. You will need to take a switched live from the clocks for the temp gauge and run a signal wire down to the sender, I used a pink wire to match the original wiring, and that is about it. The photo below shows the set up on the engine.

 

[bobtail84]

The saga continues...

I was at Brands Hatch racing circuit here in the UK on a track day and while I was attempting to reach terminal velocity I missed a gear when shifting between 4th and 5th on the start finish straight. The engine, unsurprisingly, over revved and not knowing what damage I had done made my way back to the pits. Once back in the garage there was a noticeable rattle at idle that disappeared when the clutch was slowly let out, this was a familiar sound that indicates the starter clutch was damaged. When the stator cover was removed the problem was revealed.



2 of the 3 bolts had broken that hold the starter clutch to the flywheel and to be fair it could have been a lot worse. This is not the 1st time I have damaged and replaced the 3 bolts and I know it is one of the foibles with our bikes.

I was having a mooch around the interwebs when I stumbled across a post by Centurion Motorcycle Projects​ who has designed a solution to the starter clutch problem. I contacted the owner, Brian, and arranged to send my starter ring and flywheel up to him for modification. Just for clarity I have no association or any kind of vested interest in the company, I just wanted a solution.

This is taken from his eBay listing "Suzuki GS series uprated and modified starter clutch bearing assembly arrangement. I've been working on this upgrade for many months, exclusive and only available from Centurion Motorcycle Projects. This new modified bearing assembly will eliminate for good the dreaded issues found with the OEM 3 barrel roller type bearing. Our process involves turning down this ring gear as there is always wear to a tolerance suitable for our custom sized bearing. The bearing has been designed and manufactured by us for the mounting of the new 20 point contact one way bearing, this is where the major improvement is over the old 3 point contact design. Our bearing is a weld on type eliminating the old 3 bolt fixing that were prone for becoming loose".

I sent my starter ring and flywheel up to him and received the below back the following week.





I also purchased a pair of new OEM bearing's for the ring gear just to be sure,



I re-assembled the whole lot and forgot to take more photos it's all back together and is working fine so will update with any comments or problems but I don't envisage there being any. While I was waiting for the parts to be sent back I did check all the shim gaps just in case there was any problems after the over rev incident, thankfully there were none and I fitted a rev limiter while I was rummaging around.





I will keep an eye on the starter clutch upgrade and update accordingly.

 

[bobtail84]

I figured that I haven't posted any photos of the bike in a while as it has certainly changed over the years

This is at Brands Hatch on a track day

 

[LarsKroghStea]

I bought a very cheap eBay oil temp gauge that came with it's own sensor, you will need to check the thread pitch as they are all slightly different to the Suzuki pitch. My bike was a 1000 S that had been re-framed using a GS1100 so the engine had the oil temp sensor next to the oil pressure switch but since I have now added an oil cooler the adapter has the space for a oil temp sensor, I used the sensor that came with the gauge but had to source an adapter from eBay to match the thread pitch and it all works very well. You will need to take a switched live from the clocks for the temp gauge and run a signal wire down to the sender, I used a pink wire to match the original wiring, and that is about it. The photo below shows the set up on the engine.

I see. Not really relatable to my 1981 750 engine then..

BTW; No chicken strips on those tyres Do you have a video of yourself on track?

 

[bobtail84]

Hopefully the video link works.. this was the 1st start up after the starter clutch upgrade, checking the shim gaps and changing a few shims.

 

[bobtail84]

BTW; No chicken strips on those tyres Do you have a video of yourself on track?

I have asked a couple of people if they have any on track video of me and the bike but it appears we are actually quite useless at remembering to do that sort of stuff so nothing that I'm aware of