Topic: Project 40 - CB750 K1

[CrankyOldGuy]

Here I go.  I have described some of this in New Member Introductions section under "Forty Years Later".

I have owned my K1 since April 1971.  My goal is to make her roadworthy for her 40th anniversary (near to original look but not showroom quality by any means).  I can see this costing at least $3k before I am done.  I really have no idea where my journey will take me.  This is my pre-retirement hobby.

Originally the K1 was Candy Garnet Brown but is now Candy Ruby Red which she was suppose to be when I ordered her in the fall of 71.

She has been through two major accidents: 1) off a corner at night doing 60 mph (the infamous gravel on a paved surface), and 2) an altercation with a german shepherd.  She has also had her crank case replaced due to the results of a broken chain.

The original exhaust system lasted about four years and she currently has a set of Hooker Headers 4 into 2 exhausts installed.  Due to my lack of forethought I threw away the kickstand.  But then again I will not mention the garnet brown tank or side covers or the exhaust guards to name a few.  (memo to self - inform wife need new exhaust system for Christmas)

I have attached a picture of her from last week as I found her.  She has not be ridden since 76 and is currently stored in my mother-in-law's garage (across the street from me).

Thanks

Harry O.

 

[CrankyOldGuy]

I was over today on a recon mission.  Results of recon: 1 ) both tires flat, 2) engine rolled over easily using kickstart only, 3) gears and clutch appear to work, 3) no battery (I was not sure that I had removed it), 4) a gas tank half fuel of some antique fuel (quite a smell) ( I was not sure that I had removed it), 5) seat cover cracked, but seat opened easily, 6) left cover cracked, 7) chain to be replaced,  surface rust here and there, 9) knee mark in tank (two places), and 10) key in ignition and ignition switch works (by coincidence found other key in drawer today while looking for tie).

I plan on relocating her to my garage this weekend if all goes well (memo to self - obtain pump to inflate tires).  After a thorough washing I will know better the surface damage and load up a few more pics.

Carbs are currently off and I am in the process of cleaning them.  They were quite varnished.  I have ordered some original gasket sets for them.  The cleaning will take a while; but I feel it is the most important step.

I have also ordered a new points cover as the previous one had a case of road rash (memo to self - send David Silver Xmas card).

Also I will greatly appreciate responses any to my future questions.

Harry O.

[unitedguitar]

That's pretty sweet. Clean it up a little and it'll be a cool bike. What are your plans for it?

[CrankyOldGuy]

unitedguitar,

My first goal is to get the engine to run.  Next to make her rideable.  Then to renew her a bit.  Don't know where I will finally end up.

I purchased a set of plugs today ... they are a tad more expensive than I remember 

Harry O.

[unitedguitar]

Unfortunately plugs can get expensive. Especially during the tuning process. You might foul several sets in the process and a set can run anywhere from 10 to 50 bucks depending on what you get. Its all part of the 750 experience though.

Good luck on your build. I like to see bikes as they progress so any time you can get pics would be awesome.

[CrankyOldGuy]

My brother-in-law and I extracted the Old Girl out of my mother-in-law's garage today.  I moved her across the street to my house and gave her a pressure wash to clean off 34 years old dirt and grime.  All-in-all she does not look that bad.  Some light surface rust on the chrome parts and as usual the faces of the tach and speedometer have weathered a bit.

I always wondered why Canada went metric in the 70's.  Now I know ... so I would have a vast selection of tools to use on this metric motorcycle.  But then again I have two sets of tools now .. one metric and one imperial/customary.

I will attach a few pics.  As I am not computer literate I will have to add a few posts to show all of the pics since I can not reduce the file size any further and I can only get pic per post.

Note that the carbs and air cleaner have been removed as I am working on cleaning the carbs.  Also, the timing cover is missing ... but I have ordered one along with some other goodies.  Thanks for duct tape.

Harry O   

[CrankyOldGuy]

Oooppss .. the Old Girl

[CrankyOldGuy]

Hooker headers were a poor student's way of purchasing a new inexpensive exhaust system back in the 70's.  Unfortunately to make the headers fit I had to remove the kickstand ... and ...  I threw it away.

My plans are to install the original style four pipes .. so I am looking for a new kickstand.

Harry O.

[CrankyOldGuy]

I finally caught on to the pic thing ... I think 

I have attached a couple of pictures of the engine.  There is a bit of road rash on the upper two horizontal head cooling fins due to my incident with the German Shepherd.  There is no engine serial engine as the crankcase was replaced under warranty due to a chain/crankcase failure ... large gaping whole in case.

A view of from the rear showing the 76 license plate.

A view of the tach and speedometer.  The speedometer was replaced because the arm fell off .  Probably about 25k miles on her total.

A pic of a few dents in the tank compliments of aforementioned German Shepherd.  Its a weird feeling when a dog comes out from between two parked cars when you are going 20 mph ... a sudden stop for sure and a few sparks.  It was quite pretty at night.  Another item on the list of things to do.

My main goal is to get her to start and then see where I go from there.

I hope I don't bother you guys too much ... I will even buy the popcorn. 

Harry O. 

[Stev-o]

Your not bothering us, we love this stuff! [And not all of us eat popcorn.]
I just picked up a '77 750K, so will be following yours while I restore mine.
Start looking for parts now: place a want ad in this forum and look on eBay,
here's a centerstand I found in 2 min:

http://cgi.ebay.com/ebaymotors/Centerstand-CB750-cb750k-honda-1972-_W0QQcmdZViewItemQQhashZitem45f330c38eQQitemZ300432802702QQptZMotorcyclesQ5fPartsQ5fAccessories

Buy new tires even if they look good, yours are past their life!
Motorcycle Superstore is a great webstore, free shipping if over $75.
http://motorcycle.motorcycle-superstore.com/search#w=spitfire%20s11&asug=spitfire
I bought Bridgestone's for my 550F, good reviews on this forum.


Good Luck!

[CrankyOldGuy]

meriggi,

Thanks for the info.

The carbs will be the fun part.  I have some gasket sets coming from DSS.

Also, I get to buy some neat tools that I could not afford in my youth (as I gaze on my new compression tester) 

Harry O.

[CrankyOldGuy]

Today I received a package from DSS today ... just like Christmas      Ten days from order date .. fast prompt service

Received the following:
One breaker assembly (points, condensers, etc.)
One carb float set
One carb rebuild kit
Three carb gasket sets
Advancer shaft and gasket for points assembly
Oil filter including gaskets
Oil filter bolt
Two footrest rubbers ... I just didn't like the looks of the ones I currently have .. quite distracting to me

The only thing I noticed was that the carb rebuild kit include a 110 main jet not the K1 120.

The next step is to rebuild carbs.  I now have two sets of four carbs including backing plate assembly and two air intakes. A friend of mine is a jeweller and he has a small ultrasonic cleaner that I can have to clean the small parts.

My goal is to have her started before Christmas.  The next project after that is to check out the charging system.  It never worked that well many years ago.  I believe I only had enough current to use the electric starter for the first two years, kick start thereafter.  It usually started on the first kick though.

Anyways, I have gleaned many good ideas for cleaning the carbs from the various forum threads plus the charging system.

I must start my next shopping list:
Battery
Vacuum gauges
Voltmeter, etc.

Harry O.

PS I now have a reason to dig out the old timing strobe light.

[Stev-o]

Did you consider upgrading to electronic ignition?

[CrankyOldGuy]

Meriggi

I have thought about it.  I have been reading the various threads on electronic ignition and may go that way in the future.

For now I have decided to stick with the points. Fling and setting the points, and adjusting the timing was always a good way to spend a Saturday afternoon instead of riding.   I hate to admit this but I enjoy the constant interaction between man and machine.

If I plan to do some long trips in the future the electronic ignition is a definite must.

Harry O

[andy750]

Great story Harry and Ill be watching this with interest! Check out Ottos K1 restoration thread and Johnies as well.

Good luck with it and you might consider an AGM battery when the time comes.

cheers
Andy

[CrankyOldGuy]

Back for some advice/information.

As this weekend is "suppose" to be nice up here in eastern Canada I have diverted myself from cleaning my carbs to changing the oil before it turns into molasses.  This involves changing the oil filter, cleaning the sump, cleaning the oil pump screen, cleaning the oil tank, and cleaning the oil lines.

The question I have is how far the oil pan has to drop down before it can be slid towards the rear of the cycle? Due to the arrangement of my header pipes (as shown in my avatar), pipes 2 and 4 traverse beneath the oil pan to the opposite side of the cycle so that headers 1 and 4 share the same exhaust pipe and headers 2 and 3 share the same exhaust pipe.  I hate to get the oil pan unbolted and then find out that I have to remove the exhaust system midway through the exercise.

If I find anything interesting I will post a few pics.

Thanks for the info.

Harry O.
 

[MoMo]

You probably will have to take the headers off-the few nuts and bolts involved will make access to the pan much easier-the "shortcut" of trying to work around the headers will create more struggle than is necessary.  Nice bike by the way and good luck with the rebirth, Larry

[CrankyOldGuy]

Still pondering over removing the headers to service the oil pan and oil pump screen.  Removal appears to be the right solution.

Today turned out to be sunny and warm for this time of year but windy as noted by the leaves blowing into my garage.  I have been concerned with the finish of the various chrome surfaces.  After washing with soap and water the surfaces still had a cloudy look and almost gave the appearance the chrome finish was pitted or missing.

I have had no luck in finding any phosphoric acid.  Therefore, I decided to attempt to clean the surfaces with Mothers Chrome Polish using the Mothers Ball with my electric drill.  All in all the chrome finish improved immensely.  I have included a pic of a rear shock before cleaning and a rear shock after cleaning (the pics are not of the same shock but the before and after were similar for both shocks).  Other pieces turned out equally well.  To do a proper job will require more disassembly.  At least it will save me few bucks in not having to re-chrome pieces for the short term.

It appears I have created a monster ... too many mini projects on the go at the same time 

Harry O.

[Anti-Johnny]

my shocks look similar to how yours did. I was uncertain polishing them would make a difference, but atleast from a few feet away those look much nicer. I was just going to paint mine, but this gives me hope.

[Stev-o]

I'll be buying Mother's next week!  Thanks for sharing.

[MoMo]

Phosphoric acid can be found at a Home Depot if there is one near you. It'll be in the paint department. Larry

[CrankyOldGuy]

I am back.

Since last October I have been reading a lot and buying all sorts of good stuff.  The biggest purchase so far is a complete set of HM300 exhaust pipes, with all the goodies, from DSS.

Last evening I drained the oil, removed the oil filter and oil pan.  Nothing extraordinary in the sump but I discovered "black crap" on the oil pump screen (see pics below).  I have a thread about this going on the main forum.  I ordered a new oil pump screen and o-rings from Honda.  The next step is to remove the oil pump and see how far the "black crap" has progressed.  Perhaps a rebuild is in my future 

Harry O.

[CrankyOldGuy]

Oil Pump Removal Complete

I successfully removed the oil pump.  I have included some pics below.

All-in-all the pump came off quite easily and was in remarkably good shape.  The pump still sucked and spewed oil when I turned the drive gear.

The 15x2.5 o-rings (91302-377-000) are still very pliable; but I will replace them with the new set I have on order ($6.24 CDN ea.).

I had a look at the oil pump strainer screen.  I am of the opinion that the "black crap" on the screen is remnants of the sealant the Honda mechanic used to assemble the crankcase halves.  There is sealant still on the inside of the oil pan and the crankcase where they mate together. The sealant breaks off in little hard black pieces similar to the "black crap" on the screen.  I will be replacing the oil pump strainer screen (15150-300-000   $16.74 CDN).

I am wondering if I should disassemble the oil pump further to clean it out and to replace the 46x2 o-rings (if they can be found) adjacent to the rotors.  Any thoughts or opinions?

I also had a look at the primary drive chain tensioner and the wheel look in good shape ... no material missing.

I believe this is an old question.  When I removed the oil filter, the oil filter element set spring (15414-300-000) and the oil filter spring seat (15414-300-000) were missing.  I do not remember them ever being there.  Are they required?

I will keep you up to date as my journey continues.

Harry O.

[CrankyOldGuy]

 WARNING - Boring but educational stuff follows 

1. Oil Filter Spring & Washer

Answered my own question concerning the requirement of the oil filter spring and washer.  I did a forums search on "oil filter spring" and there was a plethera of information.

It appears most likely some dummy, aka me, when changing the oil filter let the spring and washer fall into the oil collection pan along with the filter and voila the spring and washer got thrown out with the oil filter and old oil.

The spring's function is to keep the oil filter tight to the crankcase.  By keeping the oil filter tight to the crankcase there is less chance for the oil to be recirculating around the filter and lessening oil distribution to the valve train and crankshaft.  The washer keeps the spring from eating into the rubber on the end of the filter.

I will be ordering the spring and washer on Monday

2.  Lubrication System Diagram, Etc.

Although they are located in the service manual I have attached the lubrication system diagram, the oil pump diagram and the oil filter diagram for the CB750K.  I found it quite interesting to follow as I was reading up on the function of the oil pump, screen, screen, filter, etc.  It is a simple but still complicated system.

Perhaps posting these will give others the incentive to read up on the lubrication system ... the heart ... so to speak ... of the CB750.

Harry O.

[mcpuffett]

Hi Harry i'm following your thread with interest love reading about old bikes being resurrected  , i would get the bike running maybe do a few laps of the neighberhood to get it nice and hot then drop the oil to get rid of any nasty bits  , cheers Mick.