Topic: Resto for cb750k8

[letmwhirl]

I was not able to look into the carb box today. But I made a dent in the cleanup effort somewhat. First I removed all the alu corrosion on the fork lowers. The left one in photo is 85% complete, The right one is just washed. They will have a brushed satin finish. Photos will follow. Speaking of coatings, I received a photo of the first parts which have been coated.

I cleaned and removed the old paint from the front brake disc. Then removed the guages from their bracket. Afterwards painted both. The speedometer chrome back cover is too rusted so I am thinking of painting both, but the tach chrome cover is nice... I looked up the price of a new speedo chrome cover... 57€.

I also took a rubber hammer and knocked the front brake piston in just a bit in order to get it to move. Then took the air nozzle and blew it out. Honed the inside and ordered a new piston and seal. The old piston had too many rust pits. It possibly could have worked, but why chance it. Please no brake fluid on newly coated parts. Also, I ordered master cylinder kit and fork seals (dust boots are ok).

I will likely remove the motor tomorrow. Fingers crossed all goes well.

Question (s):
Where can I order a quality complete bolt kit for motor and everything else?
How can I identify if this is the factory handle bar?  I will take a photo tomorrow and measure it end-to-end then post.

[letmwhirl]

Just ordered the US model original handlebar with holes for switch calbles... yeah
Also ordered the 4carb overflow hoses and the gas tank to carb hose.
All should be delivered by the end of Nov.

[denward17]

Looking good whirl....

Those coated items look great!

[letmwhirl]

Just ordered the US model original handlebar with holes for switch calbles... yeah
Also ordered the 4carb overflow hoses and the gas tank to carb hose.
All should be delivered by the end of Nov.

Thanks,,, I could not have them coated with a flat surface ..too many rust pits. It would show up like a bad penny.
This has a little texture to the coating,,, like a wrinkle finish.. I will get a closeup later.

Oh no,,, I can't find my carb rebuild kit order... did I forget to order them?

[letmwhirl]

Just ordered the US model original handlebar with holes for switch calbles... yeah
Also ordered the 4carb overflow hoses and the gas tank to carb hose.
All should be delivered by the end of Nov.

Thanks,,, I could not have them coated with a flat surface ..too many rust pits. It would show up like a bad penny.
This has a little texture to the coating,,, like a wrinkle finish.. I will get a closeup later.

Oh no,,, I can't find my carb rebuild kit order... did I forget to order them?

Just found the order... they should be here Dec 4th... man I am old.. better make a list.

[madmtnmotors]

If you decide to freshen up the upper triple tree be aware that the stock switches are grounded through the handle bars which in turn are grounded through the handlebar clamps on the top triple tree. If the powder coating or paint coats the surfaces where the handlebar clamps down, and where the upper tree clamps to the steering stem, then you may not get enough of a ground connection for the horn and starter button to function. It has happened to more than one member here.

[BenelliSEI]

If you want original style engine cover screw set, Yamiya sends the best one at a very reasonable price. If you want to use Allen head bolts there are lots of sellers on EBay that do nice kits.

[letmwhirl]

If you decide to freshen up the upper triple tree be aware that the stock switches are grounded through the handle bars which in turn are grounded through the handlebar clamps on the top triple tree. If the powder coating or paint coats the surfaces where the handlebar clamps down, and where the upper tree clamps to the steering stem, then you may not get enough of a ground connection for the horn and starter button to function. It has happened to more than one member here.

I plan to have the 2-3's coated as well.. to ensure a complete circuit, I will run a ground all the way from the batt/m-unit area to the handle bars.

[madmtnmotors]

If you decide to freshen up the upper triple tree be aware that the stock switches are grounded through the handle bars which in turn are grounded through the handlebar clamps on the top triple tree. If the powder coating or paint coats the surfaces where the handlebar clamps down, and where the upper tree clamps to the steering stem, then you may not get enough of a ground connection for the horn and starter button to function. It has happened to more than one member here.

I plan to have the 2-3's coated as well.. to ensure a complete circuit, I will run a ground all the way from the batt/m-unit area to the handle bars.

That will do it!

[letmwhirl]

Awesome tip,,, thank you.. I only have three 3.5mm rubber tubes between my carbs. And I will look inside to see if there are restrictors. I do believe there are other metal tubes with o-ring seals on both ends which I have already replaced. Fuel was pouring out of these when I tested the motor for a start-up.

With only three rubber crossover tubes those will be the accel pump crossovers and should have little brass restrictors inside if they are original. The aluminum crossover tubes with o-rings are the primary fuel feed to the bowls. 😎

Great tip and thank you so much for mentioning this... I pulled the old tubes out of my carb box and you bet,, the restrictors are in all three of them..  I am very happy you brought this up.

[letmwhirl]

I have some questions regarding the clutch on this bike... Before tearing it apart, if I put it in gear and pulled the clutch in, the back wheel would not turn. After pulling the motor today and getting the frame, swing arm and a few other parts off for coating,, I pulled the clutch cover and proceeded to pull the clutches out and have a look.

Upon loosening the nut while holding the center pin with a screwdriver and then removing the nut, I wanted to see how far the center pin needed to turn in order to bottom out. It took at least 2 full turns,,, So is this normal? Maybe the center pin was too far out and could not release the clutches... ? Oh, and the fiber on the far right in the image is different from all the others. Look at the groves in the fiber.

Also, I took measurements of each disc (fiber and steel). Please ck out the photos and give me some feedback on what you see and think. I never seen anything like the thick steel clutch plate. The hotspots are disturbing but they appear normal otherwise,, no warping and have fairly consistent measurements.

I am pretty whipped today after the work. Pulled the motor, soaked and brushed the grease and dirt, then pressure washed the parts which I later transported to the company for powder coating.. I picked up the rims, hubs and a few other pieces from the coating company and delivered to the bike shop. He will install new bearings, spokes, true the rims and new tires. Then I came back home and pulled the cam cover and then the clutch.

I will look at your responses in the morning, since I need some extreme couching time and you guys are 6 to 8 hours behind me. Thanks to everyone for all your support and comments.

[letmwhirl]

Well, thought to look in the manual to see if I could gleen some more knowledge..and sure enough... looks like at least the clutch pack is normal and the odd fiber clutch as well.

[BenelliSEI]

Working on my Sandcast project, I had the same issue. I did the top end, carbs and ignition. I got it running sweetly but the clutch just would not free up. Took it all apart, cleaned all the gum and goo off everything. All the fibre plates and steel discs were nice and true, and all well over the minimum thickness. Put it all back together and it works perfectly! Suggest you do the same……

Also measure the free length of the clutch springs and ensure they meet spec.

Next time, don’t take your rims and spokes anywhere. Invest in a trueing/balancing stand (it costs less than what you spent having your wheels built) and do it yourself. You obviously have the skill set! The first few times can be a bit frustrating, but after that it becomes a breeze. With the stand, buy three tire “spoons”, the screw on cable to pull the tube valve through the rim, and some weights. Mounting/ balancing your own tires is even easier, and you’ll do a better job than the shop…….

[letmwhirl]

Thank you BenelliSEI for the response and suggestions. All great. After looking in the manual and fiinding the image of the clutch pack, then reflecting on the 'initial adjustment' of the center pin screw, I suspect this had much to do with the problem. Also, someone said using classic bike oils for wet clutches should be used opposed to newer silicon based oils. Any truth to that when relative to our classic wet clutch system?

I was considering doing the lacing myself. Seems to be nice addition to the shop. I have never done this and seems like a good idea. I will definitely consider it.

I forgot to take the fork lowers to the coater yesterday. There are also some small brackets and other pieces which are hidden in boxes that need some attention. So, I will go through all of them and drive back over to him this morning.

Question: With the m-unit, I want to also replace the battery, reg/rec and perhaps bulbs to led. Thoughts on battery type? Lithium Ion or Gel...  What model reg/rec is small enough and reliable to get the job done with respect to both battery types?

[letmwhirl]

Here is a photo from my bars. I think they are small and not much rise. Your thoughts?

[newday777]

I have some questions regarding the clutch on this bike... Before tearing it apart, if I put it in gear and pulled the clutch in, the back wheel would not turn. After pulling the motor today and getting the frame, swing arm and a few other parts off for coating,, I pulled the clutch cover and proceeded to pull the clutches out and have a look.

Upon loosening the nut while holding the center pin with a screwdriver and then removing the nut, I wanted to see how far the center pin needed to turn in order to bottom out. It took at least 2 full turns,,, So is this normal? Maybe the center pin was too far out and could not release the clutches... ? Oh, and the fiber on the far right in the image is different from all the others. Look at the groves in the fiber.

Also, I took measurements of each disc (fiber and steel). Please ck out the photos and give me some feedback on what you see and think. I never seen anything like the thick steel clutch plate. The hotspots are disturbing but they appear normal otherwise,, no warping and have fairly consistent measurements.

You have the factory recommended fix for rattlely clutch using the GL1000 riveted double steel plate and the 1 different fiber plate.

As to the screw adjustment of the clutch in the center of the clutch cover, read the adjustment procedure in the service manual, I think it says 1/4-1/2 turn out from just touching IIRC.....

[newday777]

Here is a photo from my bars. I think they are small and not much rise. Your thoughts?

I have a similar set of bars on my K5 and love the stance of how I sit now, it had 10" bars on it when I got it and my bad back could only take 2 hrs of riding(2 ruptured discs), now I am able to ride a 250 mile day.

[madmtnmotors]

I have some questions regarding the clutch on this bike... Before tearing it apart, if I put it in gear and pulled the clutch in, the back wheel would not turn. After pulling the motor today and getting the frame, swing arm and a few other parts off for coating,, I pulled the clutch cover and proceeded to pull the clutches out and have a look.

Upon loosening the nut while holding the center pin with a screwdriver and then removing the nut, I wanted to see how far the center pin needed to turn in order to bottom out. It took at least 2 full turns,,, So is this normal? Maybe the center pin was too far out and could not release the clutches... ? Oh, and the fiber on the far right in the image is different from all the others. Look at the groves in the fiber.

Also, I took measurements of each disc (fiber and steel). Please ck out the photos and give me some feedback on what you see and think. I never seen anything like the thick steel clutch plate. The hotspots are disturbing but they appear normal otherwise,, no warping and have fairly consistent measurements.

You have the factory recommended fix for rattlely clutch using the GL1000 riveted double steel plate and the 1 different fiber plate.

As to the screw adjustment of the clutch in the center of the clutch cover, read the adjustment procedure in the service manual, I think it says 1/4-1/2 turn out from just touching IIRC.....

The "factory recommended fix for rattely clutch" was already implemented at the factory on the 77/78 K7/K8/F2/F3 models. 

[Stev-o]

Here is a photo from my bars. I think they are small and not much rise. Your thoughts?

Those appear to be Euro or Superbike bars, have similar on my K4 and like them. It's all personal preference.

[BenelliSEI]

I use regular Castrol 10W-40 4 stroke motorcycle oil and never any clutch issues. Here’s a picture of the inexpensive truing/ balancing stand I use (recent K6 project). Great investment and building wheels is an easy skill that’s extremely satisfying!

Hints:
1. Don’t polish out the spoke “witness” marks on your hubs. They are a great clue for the direction each spoke is inserted and points.
2. I keep a few old, crappy wheels around as a reminder of where I want to end up! Haven’t used them for a while, but good insurance.

[madmtnmotors]

Hints:
1. Don’t polish out the spoke “witness” marks on your hubs. They are a great clue for the direction each spoke is inserted and points.

Excellent tip indeed. With the new spokes in place you won't see them anyway!

[letmwhirl]

Here is a photo from my bars. I think they are small and not much rise. Your thoughts?

Those appear to be Euro or Superbike bars, have similar on my K4 and like them. It's all personal preference.

True,,, I have ordered a set of bars with alittle more rise..and with holes predrilled to hide the wiring. I will be using the motogadget m-unit blue and smaller guage wiring from the switches where only ground signals are used.

[letmwhirl]

I use regular Castrol 10W-40 4 stroke motorcycle oil and never any clutch issues. Here’s a picture of the inexpensive truing/ balancing stand I use (recent K6 project). Great investment and building wheels is an easy skill that’s extremely satisfying!

Hints:
1. Don’t polish out the spoke “witness” marks on your hubs. They are a great clue for the direction each spoke is inserted and points.
2. I keep a few old, crappy wheels around as a reminder of where I want to end up! Haven’t used them for a while, but good insurance.

Very nice setup...looks like you are definitely Rock'n it with your shop arrangement. I can't remember,, did you build the wheel truing stand or purchase? Good tip on the oil... nice to hear it has no problems with the clutch.

Even after the powder coating, I can still see the impressions of the original spokes.

[BenelliSEI]

I think mine came from EBay. Looks like this one, with the “L” shaped arm for checking trueness. I think mine is actually a “VENOM” but they all look the same!

[letmwhirl]

I may have found a potential problem. In the photo below there appear to be hot spots on the back inside teeth of the clutch drum. I took the cases apart today but I broke two philliips bits in my hammer driver, trying to get the bearing oiler loose under the shifting levers. I will take the lower case with crank and trans to the bike shop tomorrow for help.