Fish's 1992 750C Engine Rebuild and Other Goodies

[Richard]

Good to see you're on to something and great video's as I expected. I still wonder how one can install the shaft incorrectly , I can't remember doing anything special when installing it, I mean hightwise there's nothing to adjust is there? But perhaps I'm missing the point and good to see you finally identified the issue. I hope you're able to get it on the road soon

[Fishrider]

It may have had something to do with the ability of the clutch rod to fall into the shorter transmission shaft. I was under the impression that you could not install the clutch shaft incorrectly either. However, the shaft can go down about 3-5mm further to the stop on the clutch cover than where it is supposed sit on the clutch rod. It can feel like it is in place when it isn’t. Although, the feel when the shaft is correctly indexed is more solid than when it is not. I think that the clutch rod could sink into the shaft exacerbated this issue because the rod could get pushed on the shaft install making it hard to judge shaft position properly. I will post my fix for this over the weekend.

[Fishrider]

Took me longer to figure out my fix for the clutch bolt. Creating new parts became a non starter because of the high cost and length of time to create a one off piece. So I ordered some nuts from McMaster Carr. I got some regular M20x1.5 nuts that were 16mm wide and some M20x1.5 that were half the width. My idea was to create a nut using 1 or two nuts and a cut off piece threaded shaft from one of my previous transmissions. I ended up using two of the half size nuts because together the were the correct width. Unfortunately, the single 16mm width nut needed one or two more threads. To set the nuts correctly I put the first nut on the output shaft and cranked it down. Then I placed the second nut on the shaft and then screwed in my piece of output shaft. I had to align everything properly so that the clutch rod spun smoothly inside the shaft and new cut piece. Then I glued the pieces together using JB Weld and left the pieces to sit with the clutch rod in place over night. My first idea was to weld the nuts together but that failed. I think because the welder I chose did not have enough experience with this type of weld. He was using a MIG and I think a TIG would have been better. He ended up destroying the first piece. I created a second piece with the left over half of the old output shaft. I decided to solder the nuts. I did a mockup with two other nuts. I cleaned the nuts, rough them up with a sandpaper drum on a rotary tool. Once I got the heat right on my torch the soldering went pretty well. I tested the solder by banging on the nuts with hammer a super hard on the cement about 10 times. It held really well. So I soldered the new nuts and then cleaned up the solder. I then glued the new threaded piece with JB Weld. I think that will be fine as there is not a bunch of pressure on that piece. It just sits there with the clutch rod spinning inside it. I cranked down the nuts to the 130nm specified. As you can see the deflection I was getting goes away. This fix added back almost exactly the 6mm that I had lost from the smaller 550 output shaft. While the set up seems to be holding, I cannot test it. For some reason I can't get the bike to start now. I deal with that in a new post in the the Carbs, air & fuel section.

About to cut up a transmission shaft

One broken transmission shaft

The original creation destroyed by the welding process

Continued in next post...

[Fishrider]

Continued from last post.

Soldered and glued

Deflection solved
https://www.youtube.com/shorts/Bl6rhE0jCkE

[ZoneAdmin]

Glad you have found a solution, I’m sure this has been a lot of stress for you. Will be interesting to know the benefits of the 6th gear.

[Fishrider]

Glad you have found a solution, I’m sure this has been a lot of stress for you. Will be interesting to know the benefits of the 6th gear.

Thank you. I still have doubts. Until this beast runs a good 200 miles With no hiccups I wont feel completely settled. I suppose it is will be nice just dealing with the regular problems associated with this bike.

[Fishrider]

This bike is officially running. The last couple issues were a broken R/R and a cam tensioner issue. Turns out my M-Unit warns you if there is a problem with the regulator. This was why the horn would honk when the engine was revved. The M-Unit was reading voltages over 16 volts and was attempting to bleed off voltage by honking the horn. Sure enough the regulator was putting out between 17 and 18 volts. I replaced it with a new Rick's R/R. Works great.

The cam chain was making some serious noise when the engine was revved. So I removed the tensioner to check it out. The bolts were switched and the upper bolt was missing a washer. After I reset the tensioner, the chain didn't make a sound.

I still have not got it out of 4 gear, but I really can't go too far given the bike is not currently registered. Once I do that I can take it on proper ride.

Everything left to do is, generally, cosmetic or a possible upgrade. I do need to sync the carbs and maybe do some tuning. I still want to take care of the dents in the tank and maybe make a color change. I also want to work on the seat at some point. I still have some aluminum polishing to do, and maybe some new rear shocks.

This has been quite a journey. Here is list of all that was done to this bike:

- Six gear swap using a 550 transmission.
- New, supposedly, better oil pump.
- Completely new electrical harness with a Motogadget M-Unit as the brain.
- Custom built button controls
- All led lights including the headlamp. The new marker/signal lamps needed some modification to fit the new LEDs.
- Custom fender eliminator.
- Single LED all in one dial. Its a little harder to see in direct sunlight, but I like the way it looks.
- Drag style handle bars.
- Venhill custom cables.
- Wiseco 810cc kit.
- Installed slightly different jets in the carbs based on best suggestions for the 810s.
- The entire engine was rebuilt (twice). Upper and lower. Painted black.
- New sprockets and chain.
- Moved ignition key from handle bars to the left side of the bike.

Here is quick walk around: https://www.youtube.com/shorts/Euuic5D9s4E

[Fishrider]

Just a couple more pics.

[Jen-etc]

This looks great! Wow, awesome job, well done!

So glad you got to the bottom of the issues!

Dial looks great

Now off to watch your vid, but really pleased to see this all up and running!

[Richard]

Looks great and I do hope you can now enjoy your hard work. Start riding now, it's summer, all other stuff can be done in winter time