Topic: UPDATE: She's Running! 1971 CB750 sat since the 80s. ADVICE needed

[scottly]

Have you checked the frame and motor VIN numbers?

[PeWe]

Rather rusty. I had opened the engine, cleaned and fixed all inside.Valves and seats probably very rusty too.
Rust flakes not good in engine.
Stock rusty fork tubes, maybe OK chrome, only need of sanding off the rust and new seals?
I should not start it since oil pump strainer can be blocked by sludge. A start will then ruin it.

[DesertKyorugi]

Have you checked the frame and motor VIN numbers?

California clean title, Vin number was checked and no history of accident or salvage.

I get it that the front fork and the brake calipers don't match and PO lies all the time but I didn't buy this bike to restore for the museum or as a show bike. It is a project for me and my son to work on so I hope we put this whole front end damage business to bed.

I am very grateful and appreciate everyone's advice and input, let's get back to looking at what I need and can do with the bike. Thanks

Rather rusty. I had opened the engine, cleaned and fixed all inside.Valves and seats probably very rusty too.
Rust flakes not good in engine.
Stock rusty fork tubes, maybe OK chrome, only need of sanding off the rust and new seals?
I should not start it since oil pump strainer can be blocked by sludge. A start will then ruin it.

It sat in the same tiny storage unit with no sun for more than 30 years. Besides surface rust, you can see a shade of green like moss on certain angles of the bike. However, all the inside of the engine appeared to be very clean and shiny. The oil was a little low on the low mark of the dipstick but it was normal color and consistency. The oil pump strainer was surprisingly clean. The oil filter is very clean as well and no funny stinky smell. We didn't take any pictures because it was getting late but I will try and get some pics tomorrow.

The carbs are shipping out tomorrow to my carb guy and we have 2 weeks to try and get the motor and gas tank ready for starting.

[scottly]

What I meant was have you checked the numbers to see if they are actually K1.

[PeWe]

You can look inside by open the clutch cover.
Open oil pan not bad idea either. There are always debris resting on the pan that should be removed as a service measure now and then.

[DesertKyorugi]

What I meant was have you checked the numbers to see if they are actually K1.

It is actual K1 - E109XXXX and 109XXXX

You can look inside by open the clutch cover.
Open oil pan not bad idea either. There are always debris resting on the pan that should be removed as a service measure now and then.

The oil pan was dropped along with the clutch cover and valve cover. Everything was checked and looked normal. Will get the rest of the body pieces off this weekend for cleaning and polishing. We will have a better view of the frame once most of the pieces are off.

[DesertKyorugi]

Definitely not K1; up to K3 calipers used a "C" shaped caliper arm to fork bracket, while K3 and up used a "T" shaped bracket. The lower on the left is a K1 "C" style, while the one on the right is the later "T" style:

Got a guy selling a lot of used CB750 parts closeby. I am going to visit and have a look. To confirm, I should look for forks with the C style like the fork on the left? And a matching brake/caliper assembly? What's a reasonable price for a set of C style forks? And the brake/caliper assembly?

Thanks

[DesertKyorugi]

OK, Need a little help with the front forks. What am I missing besides the rubber stanchions(I think that's what they are called)?

Forks are covered by expanding rubber boot, 71 came with painted headlight brackets, chrome brackets are newer.

So, I should start watching out for Valley Green headlight brackets/ears/fork like the one in your pic?

[69cb750]

fork boots - https://www.ebay.com/itm/1969-1970-1971-HONDA-CB750-NEW-FACTORY-OEM-FRONT-FORK-GAITERS-BOOTS/223887067075?epid=1511823398&hash=item3420b587c3:g:L8gAAOSwHEleM1QJ
Valley green brackets - https://www.yamiya750.com/index.php?main_page=product_info&cPath=246_251_144_77&products_id=2087
Valley green headlight - https://www.yamiya750.com/index.php?main_page=product_info&cPath=246_251_183_115&products_id=2085
forks 70/71 appear on ebay in $100 to $200 range, none today.

[DesertKyorugi]

fork boots - https://www.ebay.com/itm/1969-1970-1971-HONDA-CB750-NEW-FACTORY-OEM-FRONT-FORK-GAITERS-BOOTS/223887067075?epid=1511823398&hash=item3420b587c3:g:L8gAAOSwHEleM1QJ
Valley green brackets - https://www.yamiya750.com/index.php?main_page=product_info&cPath=246_251_144_77&products_id=2087
Valley green headlight - https://www.yamiya750.com/index.php?main_page=product_info&cPath=246_251_183_115&products_id=2085
forks 70/71 appear on ebay in $100 to $200 range, none today.

Thank you! I will start looking out for them

[The Lone Builder]

Good luck!

+1 on Hondaman’s advice re fork boots /gaiters.

I had two cheap sets fall apart within 6 months. I replaced one side with an old (hard) OEM one and it lasted longer. Until ....

[beemerbum]

Be sure to get rid of that aftermarket ignition switch holder on the handlebars and replace with the stock one that attaches to the frame on the left side. My K1 had the same stupid holder

[seanbarney41]

Be sure to get rid of that aftermarket ignition switch holder on the handlebars and replace with the stock one that attaches to the frame on the left side. My K1 had the same stupid holder

yeah, because it so much smarter to fiddle around in the dark while standing on your head every time you want to turn the key on or off all so that the key switch gets roasted by engine heat.

[lash]

One thing to check for on the Old Factory K1 frames is: Honda forgot to drill water-bleed holes in the lower frame, right behind the engine bolsters, when they put those bolsters in the frame. The frame has openings in it back by the middle downtubes (you can see them in the web supports near the footpegs) that allowed water in, and it collects behind those bolsters and can rot the frame there. Some of the holes were forgotten, some were painted over: if yours does not have those holes (one on each side, bottom of frame tube), drill in a 1.8" hole on each side to prevent frame rot in the future. It sounds like this one was garage-kept, so it's probably OK, but high-pressure car washes were born in 1967, just in time to force water into these frames!

Mark, I think a 1.8” hole is a bit much !! 

[Don R]

 Read that as 1/8" L0L! If the OD of drill bit is bigger than the ID of the tubing, the hole will be on the outside.
 Seriously though it appears you are on track.
   I like to fill the oil galley from the plug on the right end of the motor just for the first start. I've used a gauge fitting and pipe nipples, even a piece of hose and a friend holding the funnel will work. Best is an oil tank intended for auto AC compressor oil. I can turn off the oil pressure light for up to 30 seconds with one of those before I even spin the motor. I also dump some oil in the top of the motor just to help slick things up a little.

[DesertKyorugi]

Is there a complete nuts and bolts kit available for sale? I am thinking I should replace all the rusty mossy nuts and bolt.

[scottly]

I get it that the front fork and the brake calipers don't match and PO lies all the time but I didn't buy this bike to restore for the museum or as a show bike. It is a project for me and my son to work on so I hope we put this whole front end damage business to bed.

There is no reason to switch to the earlier forks and caliper if you aren't doing a restoration. Likewise for the headlight ears and fork gators. 

[PeWe]

If I owned that bike I should gather all parts to bring it back to a pure K1.
If not getting the fork cheap enough, use what you have until  find one.
You need a complete front end with complete fork, brake and fender. In USA you have tobs if parts. Most used parts sold in Europe are shipped from USA.

The newer front end need another bike so collect K2-K6 parts too
Are the gauges correct with pilot lamps? K1 can be tricky to find in shape for not much.

[Tews19]

If you are looking for stock K1 lowers, I have a set on my Sandcast that I won't be using. Pm me if interested.

[DesertKyorugi]

There is no reason to switch to the earlier forks and caliper if you aren't doing a restoration. Likewise for the headlight ears and fork gators. 

Hmmmm, if you think my forks and seized caliper is usable as is I would be happy to swap with you 

If I owned that bike I should gather all parts to bring it back to a pure K1.
If not getting the fork cheap enough, use what you have until  find one.
You need a complete front end with complete fork, brake and fender. In USA you have tobs if parts. Most used parts sold in Europe are shipped from USA.

The newer front end need another bike so collect K2-K6 parts too
Are the gauges correct with pilot lamps? K1 can be tricky to find in shape for not much.

The plan is looking out for the correct parts to replace what is not usable, or too much work to clean up. It would be stupid to replace a broken incorrect part with an incorrect part, whether doing a restoration or not. It is just common sense.

[DesertKyorugi]

Here are some pics of the gauges, unicorn/rhino triple, and hand controls. Please let me know if you see anything not correct on it. Thanks

[69cb750]

Handlebar - https://www.ebay.com/itm/HONDA-1969-1971-CB750K-CB750-CB-750-handlebars-Drilled-like-OEM-Chrome-BARS-NEW/222636624995?hash=item33d62d4c63:g:hlMAAOxyLN9SnRVs

[DesertKyorugi]

Handlebar - https://www.ebay.com/itm/HONDA-1969-1971-CB750K-CB750-CB-750-handlebars-Drilled-like-OEM-Chrome-BARS-NEW/222636624995?hash=item33d62d4c63:g:hlMAAOxyLN9SnRVs

I am looking at this one - https://4into1.com/chrome-handlebars-53100-300-000-honda-cb750-1969-1971/

And restore the Honda handlebar piece that has the lights(PO included the original piece).

[Don R]

 The lights are in your gauges. The handlebar clamps are correct.

[MauiK3]

If you want great gauges send them to Marcel. Expensive but excellent.