Project X

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Joined: Mon Mar 07, 2011 8:10 pm
Location: Chicago

Re: Project X

Postby teazer » Thu Jan 11, 2018 8:44 pm

You are correct that a GS or GSX has oil fed directly from the oil pump through both gear shafts, so it is important t get enough oil in there.

Thinking out loud for a moment, early TZ's and RDs relied on splash lubrication but later V twin racers had a transmission oil pump.

Posts: 70
Joined: Tue Dec 13, 2016 7:21 pm
Location: Poole

Re: Project X

Postby madforitkev » Thu Jul 12, 2018 5:26 pm

Fun with clutches........

So I looked at just buying a TR dry clutch from BDK. Nice kit but heart failure territory!!!

dry clutch bdk.jpg
dry clutch bdk.jpg (9.45 KiB) Viewed 19 times

So being a bit tight and needing a challenge (I have issues), I decided to make this kit based around a Honda RS250 dry clutch. The fun begins.......


Ok so I bought a BDK casing, I just couldn't be bothered with that hassle as well.

Next was disassembling the GT clutch to make .....


Now I need to graft the RS inner gear to the GT out on the primary....


After lots of pain and line up issues I have a GT/RS primary!!


I've already got the close ratio GS gears to fit but I have to do some mode to the clutch shaft to;

Fit the needle roller with a retaining circlip machined into the shaft to stop it moving too much (a little play is needed as on the GT)....


This meant modify the bearing side thrust washer to make it thinner in the middle so all the tolerances stacked and the gear didn't foul the casing but also to allow oil to the needle bearing. I also had to cut a new hole in the shaft under the bearing to let oil flow (and block the old GT one on the shaft).

Next came the clutch basket. I didn't like the steel RS one and Talon make a cool ali one. Only problem is when assembled it wont all fit in as it all screws together from the back. So I had to change the design and make a new back plate so I can assemble it all from the front..


Now the cush drive plate can go on (no more rattily springs)!


And the basket (screwed from the front)...


Then the hub...


Notice I have adapted the clutch to be a push rod (hydraulic) drive. Slave cylinder to be grafted somewhere on the final drive side. Just had to open up the GS shaft end and fit a seal.

Posts: 70
Joined: Tue Dec 13, 2016 7:21 pm
Location: Poole

Re: Project X

Postby madforitkev » Thu Jul 12, 2018 5:34 pm

So after a few months of pain, I finally have......


There is a minor detail I left out of the early post in that I needed to make a bronze bush to back upto the needle bearing circlip and via an internal O ring seal the shaft. It then had a radial seal around the basket inner gear (bit with the cusht drives in), that basically keep all the oil the right side of the casing.

The other end of the bush fits against the hub back and transmits the force onto the lock nut on the shaft end.

Anyway it seems to spin OK and doesn't grind too much :D so hopefully that is that.

Next the reed valve conversion and the squish head skull caps for the cylinder head. Both are basically done bar fettling so I should be able to post soon...

Remind me again why I started this? Oh yea the 'issues'...
Last edited by madforitkev on Thu Jul 12, 2018 5:47 pm, edited 2 times in total.

Posts: 70
Joined: Tue Dec 13, 2016 7:21 pm
Location: Poole

Re: Project X

Postby madforitkev » Thu Jul 12, 2018 5:41 pm

I am still a bit worried about oil feeds to the clutch shaft.

I haven't changed the output shaft feed system so I'm not bothered about that.

I have added an oil way in the clutch shaft for the needle bearing and am hoping the splash from the primary will be enough.

The oil for the clutch shaft/gears in the gearbox is now only splash fed (the GT had a feed from the clutch end). I might try to add a splash route to the opposite end bearing (to the basket) to at least get oil at that end of the shaft. Now I have a central push rod I will need more lube in there anyway. The GS has larger shaft oil holes that the GT so I am hoping that is enough.

Any thoughts anyone?


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