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

[DesertKyorugi]

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 ....

Are they the Cruzin Image repro sets? I have had good luck with their boots and intake holders on my other bikes and I was going to make a big purchase of all the rubber parts from them.

[HondaMan]

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 ....

Are they the Cruzin Image repro sets? I have had good luck with their boots and intake holders on my other bikes and I was going to make a big purchase of all the rubber parts from them.

I don't know the CI rubber parts. The ones I used were made in China and marketed by Tourmaster via the several aftermarket outlets. I only use the Tourmaster carb boots for testing engines in my garage because of the real short life I have seen (in these web pages) of those parts in real life. The fork boots I tried were also Tourmaster brand: in one instance I installed them on a CB750K5 I restored, and 3 years later (when I finished it) and with only 4 miles on it, they were cracked and split, all by themselves, from sitting on my covered patio those days. I got some from Honda and re-replaced them, and that owner still rides with those good boots today (that was in 2008).

[jlh3rd]

The boots on my 75 550F are the original ones .....from 1975, ....45 years old.....what else can you say.

[PeWe]

I have tested the cheap Cruzinimage carb boots on my K6. Deep cracks first season. Replaced with new stock Honda that seems to be not as good as they were from the beginning. The old Honda were harder and more durable.

I have NOS K0 boots I bought in the 80's bagged with old Honda labels to compare with. Ordered to K6, got K0 which are shorter on the head side. I found out 30 years later.

Go for new Honda boots. Many can soften the old ones with chemicals like wintergreen described on this forum.

[69cb750]

Are they the Cruzin Image repro sets? I have had good luck with their boots and intake holders on my other bikes and I was going to make a big purchase of all the rubber parts from them.

Honda and Yamiya parts are the best.
Some after market parts are pretty good.
The China parts are terrible.

[PeWe]

DSS sell Honda carb boots and rhe important chain tensioners.

Redo a cheap choice inside engine and go for better quality cost some in gaskets, oil seals, oil and important time you can use for riding the bike.

The cheap pistons from Cruzinimage is so far a well known good restore saving money for other parts.

[DesertKyorugi]

Ok, thanks for the info. Is there a difference between NOS Honda boots(more $$) and new genuine Honda boots that are on eBay for $55 shipped?

[jlh3rd]

hard question to answer for any one person as there are multiple sites that sell NOS, OEM, aftermarket, etc. Such as CMS (hondarestoration.com), David silver spares (DSS), partzilla, south side honda..etc.
You're entering the world of rebuilding, replacing, restoring so start doing research and find which sites you like. I like CMS. I've used DSS also, ...
I have seen ebay prices for items that are still for sale in these sites and prices can be cheaper......just depends...
So here's this, from CMS...

[69cb750]

Ok, thanks for the info. Is there a difference between NOS Honda boots(more $$) and new genuine Honda boots that are on eBay for $55 shipped?

Honda parts are good, nos or new, I would go $55.

[HondaMan]

I have bought quite a few NOS parts from the eBay seller JTMarks. I don't know WHERE he finds them all, but all of them have been genuine Honda NOS stuff so far, and he is real good to deal with.

[DesertKyorugi]

YOU GUYS ROCK!!! I am on the Kawasaki and Suzuki forums for my other bikes and I can say without a doubt you guys are the best.

Is there anything we should be watching out for this weekend when we start disassembling the bike for cleaning, polishing, and some rust restorations? Thanks

[jlh3rd]

mouse nests in the air filter...........yep, it happened.

[DesertKyorugi]

mouse nests in the air filter...........yep, it happened.

No worries there, the airbox is already out and cleaned

[old76cr]

Balled up aluminum  foil with vinegar works wonders cleaning up surface rust on chrome.

[DesertKyorugi]

Balled up aluminum  foil with vinegar works wonders cleaning up surface rust on chrome.

Roger that. Also following up with 0000 steel wool and Flitz.

Still trying to source complete nuts and bolts kit for the bike, if anyone has a lead please let me know. Would like to replace all the rusted nuts and bolts while I have it disassembled.

On another front, my other project bike's rebuilt carbs just came back. Here are some before-after pics so you guys can see why I send out all my carbs to my carb guy -

[Scott S]

 Looks like Rick from Oldskoolcarbs!

[754]

Is caliper black or silver, 72 uses black and I think 71, earlier is silver . Same c bracket for most of 70 thru 72.

[DesertKyorugi]

Looks like Rick from Oldskoolcarbs!

Rick's the MAN!

Is caliper black or silver, 72 uses black and I think 71, earlier is silver . Same c bracket for most of 70 thru 72.

The one on the bike is black

[HondaMan]

Check the frame metal, just behind the lower front engine bolsters, for possible rust in the frame. If there are not a pair of 1/8" holes drilled there on the bottoms, just behind the bolsters, drill some in. The K0-K2 suffered from not always getting these drain holes, or from some getting painted shut, that later rusted the frames. Another place to look:on the right side, right where the frame turns forward by the footpeg mount: just above there you will probably see some small holes that were not welded shut and could allow high-pressure car wash sprayers to let water into the frame there. The carwash was a brand-new phenomenon in 1967, and the Japanese (not just Honda) were not yet aware of it and how it could affect these bikes. They got smarter by the K4 era, welding all the frame holes shut.

[Andrew-S]

Wow, Valley Green, too! Chances are, that's an Old Factory K1. When it's all running again, it will idle like a purring kitten. It may also have the brass floats in the carbs: let me know if yours have corroded holes in them.

Yes they are brass floats. Looks pretty good for being in storage for 30+ years

At what point did the K1 change from brass float bowels or did all K1s have them?

Cheers,
Andrew

[Phoenix]

I went thru this 25,000 miles ago after I pulled my 71 out of my shed after 26 years.  Even soap and water will make it look a 100% better.  0000 steel wool on the chrome is great.  If you take the carbs or pipes off, plug the holes.  After a few weeks apart, mine siezed.  What is the build date on your bike.  GET HONDAMANS BOOK.  There is so much NEEDED ifo in there-system by system.  Cycle/Recycle has bunches of good parts That are hard to find.  He knows his stuff to.  All the info you've gotten so far is great.  If you go slow, all the parts are out there.  Get the parts manual off the site and get HONDA parts if you can.  With the parts manual, you can go to the internet with the part number and find sources.  Good luck.

[HondaMan]

Wow, Valley Green, too! Chances are, that's an Old Factory K1. When it's all running again, it will idle like a purring kitten. It may also have the brass floats in the carbs: let me know if yours have corroded holes in them.

Yes they are brass floats. Looks pretty good for being in storage for 30+ years

At what point did the K1 change from brass float bowels or did all K1s have them?

Cheers,
Andrew

For the most part, the "657A" carbs had the brass floats where the "657B" carbs received the plastic ones. But, many brass ones got changed, some even under warranty, to the 'improved' plastic ones along the way. The only improvement is the lack of fragility (and probably less $$ to make) of the plastic ones, which seem to last forever. They also cause a slightly lower float bowl depth when riding, compared to brass.

[Andrew-S]

Wow, Valley Green, too! Chances are, that's an Old Factory K1. When it's all running again, it will idle like a purring kitten. It may also have the brass floats in the carbs: let me know if yours have corroded holes in them.

Yes they are brass floats. Looks pretty good for being in storage for 30+ years

At what point did the K1 change from brass float bowls or did all K1s have them?

Cheers,
Andrew

For the most part, the "657A" carbs had the brass floats where the "657B" carbs received the plastic ones. But, many brass ones got changed, some even under warranty, to the 'improved' plastic ones along the way. The only improvement is the lack of fragility (and probably less $$ to make) of the plastic ones, which seem to last forever. They also cause a slightly lower float bowl depth when riding, compared to brass.

Thank you Hondaman,

Here's my carb float bowls on my US spec 20k 11/70 build survivor K1 which was imported from Wisconsin to the UK in 2009 and has sat unused for nearly 5 years. Not sure whether the carbs are 657A or B or if the float bowels were brass or have been changed?

Cheers, Andrew





 

[69cb750]

For the most part, the "657A" carbs had the brass floats where the "657B" carbs received the plastic ones. But, many brass ones got changed, some even under warranty, to the 'improved' plastic ones along the way. The only improvement is the lack of fragility (and probably less $$ to make) of the plastic ones, which seem to last forever. They also cause a slightly lower float bowl depth when riding, compared to brass.

We need owners with low mileage original bikes to report.
My four 71's had/have brass floats, part number stayed the same, vin change unknown ...

For the most part, the "657A" carbs had the brass floats where the "657B" carbs received the plastic ones. But, many brass ones got changed, some even under warranty, to the 'improved' plastic ones along the way. The only improvement is the lack of fragility (and probably less $$ to make) of the plastic ones, which seem to last forever. They also cause a slightly lower float bowl depth when riding, compared to brass.

What parts changed for 657B ?

[DesertKyorugi]

What is the proper seat for my 71? What year range should I look for? Thank you