Topic: Just purchased my first project bike - Updated 7-30, New Pics!

[grande351]

Hello everybody, I've just purchased my first project bike!
It's a 1971 CB 750 K1. I love the original CB 750s and have always wanted one. I've known about this particular bike for close to 25 years. It belongs to my cousin, who bought it from the original owner, who I also know. The bike only has about 3,500 miles on it and as far as I know hasn't been run since the mid 80's. It's always been stored inside, but is pretty scruffy and dirty. It looks to be complete except for two major issues. It has an aftermarket 4 into 2 exhaust and has damage to the fins on the right-hand side of the cylinder head, which I assume I'll have to replace. The story I've heard is the original owner either dumped it, or ran into something, which caused the head damage and possibly damaged the exhaust too. Even with that, I still think I got a pretty good deal. I'm supposed to pick the bike up this week. Are there any major pitfalls I should know about before I start working on it? Any suggestions on how to approach the restoration would really be appreciated. I'm a newbie here, so please don't be too tough on me!

I'll try and post some pics I took of it today and some more when I get it home.

[Hush]

Pitfalls on old SOHC4 bikes (1) it will cost you money
                                        (2) it will cost you money
                                         (3) it will cost you money
                                        (4) you will love it even though it costs you money

Funny that a bike with only 3500 miles on it would need an aftermarket exhaust?

[KB02]

PICS!!!!!! 

Sounds like a nice project. Keep us updated.

[grande351]

Pitfalls on old SOHC4 bikes (1) it will cost you money
                                        (2) it will cost you money
                                         (3) it will cost you money
                                        (4) you will love it even though it costs you money

Funny that a bike with only 3500 miles on it would need an aftermarket exhaust?

I won't know for sure until I speak to the original owner, but I believe the stock exhaust was damaged in the same incident that caused the head damage. I suppose he just replaced it with an aftermarket setup.

[grande351]

Here's some photos of my "barn find" CB 750 (well it is in a barn! ). Lots of dirt and surface rust, but I think it can be saved. I don't think it's too bad for $400.

[grande351]

Here are a few more pics. I was wrong about the mileage in my first post. It has 3,841 miles. I'll take some more when I (hopefully) get it home next week and wash off the dirt and bird crap.





Here's a close-up of the head damage, looks bad, but it's only cosmetic. I'll have to fix it though. I assume I'll need to replace the head. Anyone got a good used cylinder head? 

[mrbreeze]

OUCH!!!!! ... Still....it looks like a good bike for the price.You will have to pull the motor to swap out heads but what better time to polish the hell outa the valve cover?

[MCRider]

Pitfalls on old SOHC4 bikes (1) it will cost you money
                                        (2) it will cost you money
                                         (3) it will cost you money
                                        (4) you will love it even though it costs you money

Funny that a bike with only 3500 miles on it would need an aftermarket exhaust?

While in this case it may have been because of the accident...

back when I was in shops, 1970 to 1976, brand new bikes, especially CB750s, they would throw away the stocker 4-4 and put an RC on it etc. before it even left the showroom.

Kinda like the Harley guys do now. Can you imagine the dumpsters full of stock harley exhaust systems? I mean every single one of those turds has aftermarket pipes on them before they hit the streets.

[MCRider]

Isn't it freaking amazing how with only 3500 miles on it, virtually every single part needs reconditioning and looks like...

BTW heads are very easy to get on eBay. But go slow on the bidding, I paid way too much for one, as just the next week, 2 went for half what i paid.

Never fear, it will be fine. I appreciate the provenance.

[Hush]

Ouch that's one Hell of a toothache on that head, I'd get her running and not worry too much about the looks for a while.
A clean up and your $400 will look like a great investment.

[KB02]

Judging by this picture, looks like it will need a new Head gasket anyway, so time to pull the head. Talk to MReick on these boards. He might have a "Messaged" head he could sell you. 

[grande351]

Judging by this picture, looks like it will need a new Head gasket anyway, so time to pull the head. Talk to MReick on these boards. He might have a "Messaged" head he could sell you. 

That sounds like a good idea, if "massaged" means what i think it does 
I'd like to keep it looking stock on the outside, but I'm all for getting more grunt from the motor. Especially if I have to rebuild it anyway.

[cleveland]

Nice find.  Be careful........it gets addicting. 

[Johnie]

That might be a K2 there?  I did not think the K1 had the hand rail and did not have the idiot lights in a cluster under the gauges.  The K1 had matching paint for the headlight bucket and fork ears.  I see yours has black bucket and chrome ears.  What does the build date say on the black and silver sticker on the neck?  Should be a month and year like 8/72 in the corner of the sticker on the right side of the neck.  Sure looks like a great find for you!!!  I wonder if it is a K2 built in 1971?  
Here is some info from Cycle Chaos:

The CB750K1 Four was sold from 1970-71 and was available in one of four colors: Candy Ruby Red, Candy Gold, Valley Green Metallic, or Candy Garnet Brown. The gas tank stripe was gold. The tank, side covers, and upper forks were of the basic color (red, gold, green, or brown). The side covers were smaller and there were no slots on the leading edge. There was a two-throttle cable system (pull open and pull closed). The headlight shell was also the basic color. The exhaust system was a 4-into-4. The engine was a 736cc SOHC 2-valve dry sump inline 4 cylinder linked to a 5-speed transmission and chain drive. The serial number began CB750-1044650.

The CB750K2 Four was sold in 1972 and was available in one of three colors: Brier Brown Metallic, Flake sunrise Orange, or Candy Gold. The gas tank stripe was gold but as with previous models, the Gold tanks had a black stripe. The side covers were smaller than the K0 model and there were no slots on the leading edge. The upper forks were chrome. The headlight shell was black. The taillight and side reflectors were larger. There was a two-throttle cable system (pull open and pull closed). The exhaust system was a 4-into-4. The engine was a 736cc SOHC 2-valve dry sump inline 4 cylinder linked to a 5-speed transmission and chain drive. The serial number began CB750-2000001.

[grande351]

That might be a K2 there?  I did not think the K1 had the hand rail and did not have the idiot lights in a cluster under the gauges.  The K1 had matching paint for the headlight bucket and fork ears.  I see yours has black bucket and chrome ears.  What does the build date say on the black and silver sticker on the neck?  Should be a month and year like 8/72 in the corner of the sticker on the right side of the neck.  Sure looks like a great find for you!!!  I wonder if it is a K2 built in 1971?  
Here is some info from Cycle Chaos:

The CB750K1 Four was sold from 1970-71 and was available in one of four colors: Candy Ruby Red, Candy Gold, Valley Green Metallic, or Candy Garnet Brown. The gas tank stripe was gold. The tank, side covers, and upper forks were of the basic color (red, gold, green, or brown). The side covers were smaller and there were no slots on the leading edge. There was a two-throttle cable system (pull open and pull closed). The headlight shell was also the basic color. The exhaust system was a 4-into-4. The engine was a 736cc SOHC 2-valve dry sump inline 4 cylinder linked to a 5-speed transmission and chain drive. The serial number began CB750-1044650.

The CB750K2 Four was sold in 1972 and was available in one of three colors: Brier Brown Metallic, Flake sunrise Orange, or Candy Gold. The gas tank stripe was gold but as with previous models, the Gold tanks had a black stripe. The side covers were smaller than the K0 model and there were no slots on the leading edge. The upper forks were chrome. The headlight shell was black. The taillight and side reflectors were larger. There was a two-throttle cable system (pull open and pull closed). The exhaust system was a 4-into-4. The engine was a 736cc SOHC 2-valve dry sump inline 4 cylinder linked to a 5-speed transmission and chain drive. The serial number began CB750-2000001.

Thanks for the info Johnie!!! It's entirely possible that it's an early K2. I've got a lot to learn about all the differences between the years. When i said K1, I was just going by the year on the sticker, which is 71. I don't remember what the month was. I will also check the serial number when I pick it up this week. I guess like with cars, they start building the next model year in the last part of the current year. Are there any good books on these bikes? Does being a K2 make it less desirable? Just curious, I never planned on making a fortune on it. I just wanted something that would make a fun first project, and i think it will be!

[Johnie]

That might be a K2 there?  I did not think the K1 had the hand rail and did not have the idiot lights in a cluster under the gauges.  The K1 had matching paint for the headlight bucket and fork ears.  I see yours has black bucket and chrome ears.  What does the build date say on the black and silver sticker on the neck?  Should be a month and year like 8/72 in the corner of the sticker on the right side of the neck.  Sure looks like a great find for you!!!  I wonder if it is a K2 built in 1971?  
Here is some info from Cycle Chaos:

The CB750K1 Four was sold from 1970-71 and was available in one of four colors: Candy Ruby Red, Candy Gold, Valley Green Metallic, or Candy Garnet Brown. The gas tank stripe was gold. The tank, side covers, and upper forks were of the basic color (red, gold, green, or brown). The side covers were smaller and there were no slots on the leading edge. There was a two-throttle cable system (pull open and pull closed). The headlight shell was also the basic color. The exhaust system was a 4-into-4. The engine was a 736cc SOHC 2-valve dry sump inline 4 cylinder linked to a 5-speed transmission and chain drive. The serial number began CB750-1044650.

The CB750K2 Four was sold in 1972 and was available in one of three colors: Brier Brown Metallic, Flake sunrise Orange, or Candy Gold. The gas tank stripe was gold but as with previous models, the Gold tanks had a black stripe. The side covers were smaller than the K0 model and there were no slots on the leading edge. The upper forks were chrome. The headlight shell was black. The taillight and side reflectors were larger. There was a two-throttle cable system (pull open and pull closed). The exhaust system was a 4-into-4. The engine was a 736cc SOHC 2-valve dry sump inline 4 cylinder linked to a 5-speed transmission and chain drive. The serial number began CB750-2000001.

Thanks for the info Johnie!!! It's entirely possible that it's an early K2. I've got a lot to learn about all the differences between the years. When i said K1, I was just going by the year on the sticker, which is 71. I don't remember what the month was. I will also check the serial number when I pick it up this week. I guess like with cars, they start building the next model year in the last part of the current year. Are there any good books on these bikes? Does being a K2 make it less desirable? Just curious, I never planned on making a fortune on it. I just wanted something that would make a fun first project, and i think it will be!

The CB750K came out in 1969 with the 69 & 70 being pretty much the same with the exception of the sandcast which I will not get into here.  The 69 & 70 seem to be the most sought after 750's.  The K2 is a very nice bike and I would for sure buy one.  I like the 750's that came out from 69 - 76.  In 1977 the style changed to more the modern look for the times.  I did have a 77 CB750K which was my first 750.  But I always like the older ones which is just my personal taste.  I think you have a nice bike there which looks pretty complete.  Just to give you a little idea of some cost, I spent around $1,000 to have all my chrome redone.  OEM mufflers are still available at a cost of around $800 - $1,000 for the HM341's which Honda still makes for the collectors.  The 69&70 bikes has the HM300 mufflers which some guys put on the K2, K3, K4, etc. because they sound so much nicer than the 341's.  But the HM300's are a little bit more costly like around $1,200.  You can worry about that when you decide what you want to do with the bike.  You may not want to keep it stock...that is up to you.  All of that being said, it is a nice restorable bike and I am sure we all enjoyed the pictures.  Do not be afraid to ask questions.  Many of us were in the same boat as you at sometime.  The guys here are so friendly and willing to share their expertise.  Welcome...

[PxTx]

I beleive I've got a decent cylinder head.  I need a left side outer front exhaust pipe.  You weren't thinking about changing them were you?  Interested in a trade?

Bike looks to be a K2.  I've got one the same color.  SOme parts are unique to a K2, but it looks like it's pretty complete!

[grande351]

Well, after a long wait due to issues with the seller, I've finally got the bike home!!! I've started to do a little clean-up on it and it looks much better. I plan on working on it this weekend and will take some pics. So here's the good and bad so far:

Good: 1. The motor is not stuck. It turns over with the kickstart and starter motor. Seems to have good compression as well. 2. The clutch is not stuck and works smoothly. 3. The rear brake works well and doesn't stick. 4. It seems like the electrics are working. The battery is stone dead, but I connected a charger and got the headlight to come on (high and low beam work). The horn and starter work too.

Bad: 1. It appears that the front master cylinder is "toast". The handle just flops back and forth like it's not connected and the reservoir is full of some white-ish crystals instead of fluid. 2. There's a light coating of surface rust in the tank along with some 18 year old gas (nasty!) I plan on draining this and removing the tank this weekend. 3. The throttle is stuck. I don't know if it's the cables or the carbs that are to blame. I'm sure I'll end up replacing the cables and rebuilding the carbs anyway. 4. There's a good bit of surface rust on the chrome. I will clean it as best I can and replace it as I go. The paint is decent, but has a few nicks and chips. The left side cover is broken where it attaches at the bottom, probably from someone yanking on it to remove it at some point.

That's what I've found so far. I'm sure there will be other issues to come. I'm still happy with my purchase. I feel like it deserves better than it's been treated so far by the previous owners! I'm lucky in that there's a local guy who really knows Hondas and is very willing to help me. He owned a sunrise orange K2 just like mine back in 72. He also has a 1975 Gold Wing that he's owned since new. It's spotless and has over 100,000 miles on it. He currently rides a 1985 Gold Wing that he's put 180,000 miles on!! He should know how to keep them running 

BTW. It is definitely a 1972 K2 model. The build date is 11/71 and the s/n is 20005??? (can't remember and I didn't write it down)

[cleveland]

Doh!  Never mind.   

[noahspop]

just curious, what were the issues with the seller?
didn't you say he was your cousin?
well glad you got it home. that is for sure a nice fine.
i can't wait to see the progress.

[SanDogDewey]

I'd clean her up and clean out the carbs, flush the tank, squirt some WD down those cables, change the oil, lube the chain, flush and fill the master cyclinder....and take it out and ride it!!!  Oh and check out those old tires too. With a little luck, she'll probably fire up and run pretty good.

That's what I've done with my 1000 mile '77 CB750 so far. I'm having a ball with it. This winter I'll take her apart and make her pretty, but for now I'm just enjoying riding it around.

[Johnie]

You should be able to pop a float bowl off the bottom of one carb and get an idea how much work you will have to do there.  Hopefully and our fingers crossed...the guy drained the bowls of fuel before it sat all those years.  If he did, your work will be much easier on the carbs.  Sticky throttle is common.  As far as the white stuff in the master, I used a shop vac to suction that stuff out of my K1 that sat 7 years.  I then put regular brake fluid in and bleed the air out and all is fine.  I got pretty lucky.  You will want to put some PB Blaster or penetrating oil on the bleeder screw overnight to loosen it up.  You do not want to break that bleeder off by the front wheel caliper.  OK, I better stop giving you things to do...enjoy and it is great - YOU SAVED ANOTHER FROM THE JUNK PILE. 

[grande351]

just curious, what were the issues with the seller?
didn't you say he was your cousin?
well glad you got it home. that is for sure a nice fine.
i can't wait to see the progress.

It wasn't anything serious. The bike was stored at my uncle's place, which is near me, and is for sale since he recently passed away. My cousin, his son, now lives about three hours away. It was a pain trying to get him up here so I could go and get it. He kept telling me he was coming, but always came up with a reason why he couldn't. He doesn't have a history of being very reliable, so I was getting worried! I thought they might sell the property or something like that. He's got a lot of cars and other stuff stashed there. For instance, there's a CB77 Super Hawk and a 305 Dream in the same barn where my bike was. He's not ready to part with those, though. (I asked!!)

[grande351]

Doh!  Never mind.   

Huh? 

[grande351]

I'd clean her up and clean out the carbs, flush the tank, squirt some WD down those cables, change the oil, lube the chain, flush and fill the master cyclinder....and take it out and ride it!!!  Oh and check out those old tires too. With a little luck, she'll probably fire up and run pretty good.

That's what I've done with my 1000 mile '77 CB750 so far. I'm having a ball with it. This winter I'll take her apart and make her pretty, but for now I'm just enjoying riding it around.

You sound like my father! That's exactly what he thinks I should do. I'm really torn about what I want to do. I really want to do a complete nut and bolt, frame-up resto on it, but that could take a while due to money and time constraints. I could also clean it up as best I can, get it running and ride it. That may be the best way. I could then replace stuff as I go along (and as my budget allows!)
I think the tires might be the original ones. Did these come from the factory with Bridgestones? They're in decent shape, but there's no way I'm going to ride around on 38 year old tires!!! I'll keep them, though. They would be good for a concours bike that doesn't get ridden.