New Guy, '81 CB750 Custom

Posted: Sat Jan 23, 2010 4:28 pm

Hello forum,

I just got my first CB yesterday: 1981 CB750 Custom

It has 11,201 miles - main reason I bought it.

Here's the text from the craig's list ad I bought it from:

"This is the second Honda cb750 I have done
in the last year, I bought the Bike from a gentleman who said he bought it
from the original owner, The Bike had sat for years ( Like 10 plus) in a
shed under a bike cover, I chose to buy it, because it had such low miles,
and the engine and transmission were in good shape, I brought the bike home,
I disassembled much of the Bike
Here is what I have done
Replaced gas tank with a better tank from a 1980 CB 750 (old tank was rusted inside and large dent) and coated the inside with ReCoate
New Battery
New gaskets ( Valve Cover, Clutch, Lower crank cover, Carb Bowls)
New Fork seals
Checked and greased wheel bearings
New Oil filter, and New Oil filter cover, spring, Oil pan bolt
Changed fluids
Removed Old factory air box and Evap box ( these caused Problems, Honda Changed them in 84)
Replaced air box with a set of 52MM chrome air pods
New Paint, including some engine trim
Installed a battery buddy system
replaced foot peg
replaced rusted rear fender and light assembly
I have $1600 in the Bike, some of it spent at the dealership, Like I said I
just enjoy working on Bikes, these bikes are collectors as you can see
online, I have seen these Bikes sell for as much as $3000 on Ebay,at the
right time of year, I have just bought another project Bike, and I only
really have room to work on one at a time, So I need to move this Honda
CB750,
the Bike will need a new tach gasket, ( simple) I did not realize it was
bad until after I put the new valve cover gasket on, it needs some new turn signal bulbs, or I was going to just order some nice LED turn signals, they are much brighter and safer .A new set of Plugs ( I have them)
The bike comes with Manual, a new set of Plugs, I even have a few extra boxes of parts off
another CB750 that will go with it!"

Seemed good enough to me, so went ahead and had the guy drop it off yesterday. It was running on 3 of the 4 cylinders when I got it yesterday, changed the spark plugs this morning and now it won't start Crying or Very sad

Checked all the sparks on each plug and they all seem pretty weak with new plugs. So, tomorrow I'm going to go through the ignition system and start troubleshooting.

I'd post some pics if I could figure out how...

Anyways, hello and anyone who can point me in a good direction on where to start with these things is awesome.

Posted: Sat Jan 23, 2010 4:40 pm

Welcome.
Where to start, well, I'd start by getting rid of those pods. I'm sorry, but the guy that sold you that bike obviously doesn't like working on them. He much prefers to simply screw with them.
The factory airbox is a must on these bikes with unmodified carbs. In fact, my 1000 won't even start without a factory air filter in the airbox. Another thing to check is the brand of plugs. You need NGK or Nippon Denso. Other brands pretty much suck.
Your plug wires and caps are probably from the 80's so it wouldn't hurt to change them. There is a modification using GM coils instead of the factory coils which will allow you to use sealed 8mm plug wires as well. An easy mod documented on this site. Speaking of documents, if you peruse the technical documents section, you'll find a factory service manual for your bike for free. Can't beat that deal.
Good luck fixing all the things your PO did to the bike. Once done, it should be a nice ride.

Posted: Sat Jan 23, 2010 4:56 pm

Quote:

Removed Old factory air box and Evap box ( these caused Problems, Honda Changed them in 84)

thats weird

Posted: Sat Jan 23, 2010 5:13 pm

holysmokes wrote:

Quote:

Removed Old factory air box and Evap box ( these caused Problems, Honda Changed them in 84)

thats weird

Exactly.
I don't want to be harsh, but if it were me, I'd be looking to get my money back and buy a different bike from somebody else.

Posted: Sat Jan 23, 2010 5:14 pm

Welcome to the site alreadygone ... Smile

I've never heard that excuse for pods before .

You'll do yourself a big favor by going through the Checklist ( link in my sig ) .

Posted: Sat Jan 23, 2010 8:24 pm

[/quote]

Exactly.
I don't want to be harsh, but if it were me, I'd be looking to get my money back and buy a different bike from somebody else.[/quote]

Thats a little ridiculous OD. He didnt even say what he paid for it. Rolling Eyes

Posted: Sat Jan 23, 2010 9:17 pm

[quote="alreadygone"] It was running on 3 of the 4 cylinders when I got it yesterday, changed the spark plugs this morning and now it won't start

Kill switch on Question

Posted: Sat Jan 23, 2010 9:26 pm

Yep...go through SeanG's checklist (in my signature, too) as a place to start. Don't worry about the pods/airbox just yet. It should run with pods but will run better with the airbox back on. Check and clean all connections (plug wires, coils, etc) and check your voltage at the battery at 3K RPM....

Posted: Sat Jan 23, 2010 10:46 pm

jk333 wrote:

Exactly.
I don't want to be harsh, but if it were me, I'd be looking to get my money back and buy a different bike from somebody else.[/quote]

Thats a little ridiculous OD. He didnt even say what he paid for it. Rolling Eyes

[/quote]

Not even close to ridiculous.
Take a look at these red flags:

and the engine and transmission were in good shape
how did he know they were in good shape? because it has "low" miles? That's no indicator.
Removed Old factory air box and Evap box ( these caused Problems, Honda Changed them in 84)
Really? What kind of problems? Did they change airboxes in 84 because they quite making the CB750 Customs?

New Paint, including some engine trim
With $1600 in the bike, including purchase price, I can imagine the great paint job. Rolling Eyes

these bikes are collectors as you can see
online, I have seen these Bikes sell for as much as $3000 on Ebay
We all watch ebay. How many 750 Customs have you seen go for 3 grand? I haven't seen a single one. I've seen a couple pristine 1000's go for nearly that, and maybe one get bid up just over that, but no 750's, sorry.
I have just bought another project Bike, and I only
really have room to work on one at a time, So I need to move this Honda
CB750
Don't know about you, but my experience is, guys don't put nearly as much care into a project they are going to "move" as they do one they are going to ride.
the Bike will need a new tach gasket, ( simple) I did not realize it was
bad until after I put the new valve cover gasket on
Who, on their second CB750 project of the year would be taken by surprise by this? Replace the valve cover gasket, grommets, and tach gasket.
it needs some new turn signal bulbs
Yeah, let's paint the engine and/or the bike rather than fix the turn signals. That makes sense. Not.

I have no desire to rain on anybody's parade, but, I can't sit back and say nothing.
However, keep or return it is not my decision, so I did make some suggestions to help get started making it right.
Nope, I don't feel rediculous at all. Wink

Posted: Sat Jan 23, 2010 11:16 pm

Haha, thanks for the help guys. Yeah, I don't know about the guy who had it before me but I don't think he did anything worth returning it. Although, I do appreciate your comments OD.

I paid $1200 for it. May have been too high, I'm not sure. But I shopped for 3 months and saw 3 DOHC CB's. One guy had done a full restore/chop into a cafe racer and wanted almost $5,000. The other was in shit shape with a boatload of miles for $800. When I saw this one, I jumped on it.

Thanks for the welcomes, I look forward to getting cozy in here.

Posted: Sat Jan 23, 2010 11:24 pm

alreadygone wrote:

Haha, thanks for the help guys. Yeah, I don't know about the guy who had it before me but I don't think he did anything worth returning it. Although, I do appreciate your comments OD.

I paid $1200 for it. May have been too high, I'm not sure. But I shopped for 3 months and saw 3 DOHC CB's. One guy had done a full restore/chop into a cafe racer and wanted almost $5,000. The other was in shit shape with a boatload of miles for $800. When I saw this one, I jumped on it.

Thanks for the welcomes, I look forward to getting cozy in here.

I'd say that changes the complexion of the entire situation.
If you're satisfied, that's all that matters. As for the rest, we're here to help. thumbs up

Posted: Sat Jan 23, 2010 11:52 pm

The airbox and pod story was total BS. Makes me wonder about the rest of it.

You undoubtedly have enough there to get a nice bike out of it. I'd start by putting a stock airbox and filter back on it though.

Honda changed the whole big bike lineup in 84 BTW, got out of the inline 4s, but they still had airboxes, even now.

Posted: Sun Jan 24, 2010 12:06 am

Yeah, I'm wondering too. I've decided I'm going to just work my way through the entire bike and not take anything for granted. I want this to be my daily rider eventually. However, this is my first foray into significant mechanical work outside of doing all the maintenance on my Wrangler. My buddy just got an '83 v45 Magna to restore so I have a partner in crime. Starting with SeanG's checklist sticky...

Posted: Sun Jan 24, 2010 12:23 am

alreadygone wrote:

Yeah, I'm wondering too. I've decided I'm going to just work my way through the entire bike and not take anything for granted. I want this to be my daily rider eventually. However, this is my first foray into significant mechanical work outside of doing all the maintenance on my Wrangler. My buddy just got an '83 v45 Magna to restore so I have a partner in crime. Starting with SeanG's checklist sticky...

There's some interesting (and useful) information concerning CB's and Magnas at this site http://www.motorcycleproject.com/index.html

Posted: Sun Jan 24, 2010 12:30 am

alreadygone wrote:

Yeah, I'm wondering too. I've decided I'm going to just work my way through the entire bike and not take anything for granted. I want this to be my daily rider eventually. However, this is my first foray into significant mechanical work outside of doing all the maintenance on my Wrangler. My buddy just got an '83 v45 Magna to restore so I have a partner in crime. Starting with SeanG's checklist sticky...

Hey, I just noticed you're in Charlotte, too. When I finally get back there I'll make sure to let you know of any bike nights. Also, there's a place in Waxhaw that seems to have old parts for fair prices. See them once in awhile on Craigslist....

Posted: Sun Jan 24, 2010 12:43 am

D-Day wrote:

Hey, I just noticed you're in Charlotte, too. When I finally get back there I'll make sure to let you know of any bike nights. Also, there's a place in Waxhaw that seems to have old parts for fair prices. See them once in awhile on Craigslist....

Well, I'll be damn. Hopefully, I'll have it running by then. Rolling Eyes

I'm technically in Waxhaw, so lemme know what place you're talking about.

Posted: Sun Jan 24, 2010 1:20 am

alreadygone wrote:

D-Day wrote:

Hey, I just noticed you're in Charlotte, too. When I finally get back there I'll make sure to let you know of any bike nights. Also, there's a place in Waxhaw that seems to have old parts for fair prices. See them once in awhile on Craigslist....

Well, I'll be damn. Hopefully, I'll have it running by then. Rolling Eyes

I'm technically in Waxhaw, so lemme know what place you're talking about.

I'll post it when I find the link.

You know, your avatar pic reminds me of a local 750 belonging to a member who died in a crash a couple of years ago (TheSneak). He ran a construction company out of Pineville. Here's his bike:

Posted: Sun Jan 24, 2010 1:30 am

I can only hope I get there one day...

Posted: Sun Jan 24, 2010 2:56 am

Howdy
The plug wires just push onto small pins at the ends of the coils. Un-screw the caps, clip off like a 1/4 of an inch off the plug wires, make sure that the pin is clean then re-install the wires and caps. Yes make sure that the plugs are NKG D8 EA, that's what these bike like most. Make sure that you are getting good connection at the plugs too and that the battery is fully charged. Should start and run even if you have a problem with the charging system.

Posted: Sun Jan 24, 2010 3:35 am

Also look down in the coil where the wire goes and make sure that the contact point is still there. They have a way of corroding into oblivion.

Posted: Sun Jan 24, 2010 4:05 am

alreadygone wrote:

I can only hope I get there one day...

Can't find the Waxhaw link, but here's one in Salisbury from a previous post:

Starship Engineering has several complete motorcycles and parts for all CB models. We have everything from gas tanks, plastics, transmissions, cases, electrical systems, and fuel systems to complete frames and motors. We are locate at 5350 US HWY 601N, Salisbury, NC. You can contact us between 10:00-6:00 M-F, 10:00-2:00 Sat at
704-636-3097 or contact us via e-mail at llewellyntd@yahoo.com

Posted: Thu Feb 04, 2010 2:16 pm

[Haha, thanks for the help guys. Yeah, I don't know about the guy who had it before me but I don't think he did anything worth returning it. Although, I do appreciate your comments OD.

I paid $1200 for it. May have been too high, I'm not sure. But I shopped for 3 months and saw 3 DOHC CB's. One guy had done a full restore/chop into a cafe racer and wanted almost $5,000. The other was in shit shape with a boatload of miles for $800. When I saw this one, I jumped on it.

Thanks for the welcomes, I look forward to getting cozy in here.]

The market for these bikes changes all time. $1,200.00 is a reasonable price if you strongly desire the bike. It's your money right? I picked up mine for $275.00 and will put about $1,000.00 total into it; and it sounds like the work your putting into your machine mimics mine closely. I estimated all my restore costs up front, I knew I'd put $1000.00 into it, so I needed to find a bike at a low initial price point. It stayed in the market for a year, but lo and behold, the opprotunity and bike came. I use Kelley Blue Book (KBB) motorcycle retail values as a reference:

http://www.kbb.com/motorcycle/retail?r=259769869157937312

Not as gospel to the value of a given bike, just as a reference to ensure I have a baseline value. If it's much more than the KBB retail price, I start asking the owner why. If he can back up a higher value, so be it. The baseline retail value of your bike (and mine) in fully reconditioned/excellent condition is $1190.00. Milage of course comes into play a bit so take that for what its worth.

From one 81 CB 750 owner to another, good luck with that rid, be safe and enjoy!

Max

Posted: Thu Feb 04, 2010 7:34 pm

Host your pics on Photobucket or somewhere like that.. Then use [img] photolink [/img]

That will get your pictures posted... (oh 640X480 please..)