Author Topic: Came across 1974 cb 750 that is near mint, sitting 30 yrs (Read 28787 times)

Trevdawg · « **Reply #175 on:** July 08, 2012, 09:15:40 AM »

Bowls before and afterwards.

MRieck · « **Reply #176 on:** July 08, 2012, 12:02:19 PM »

Quote from: fastbroshi on June 26, 2012, 02:33:48 AM

Quote from: Hinomaru on June 22, 2012, 12:17:26 PM

Hino, what table is that? I had a chance to use one just like that to service the rear end bearings on my VFR and it was a joy not to have to sit on the ground to work on it.

It is a Handy lift

James T Kirk · « **Reply #177 on:** July 09, 2012, 09:57:19 PM »

hey Dawg

just want to give you a heads up because i'm still working out the bugs in my 30 yr old survivor. my latest debacle are the insulators that connect the carbs to the head.

old rubber gets hard=hard rubber cracks=cracked insulators=vacuum leak!

aaahhhh, the vacuum leak! engine runs lean, idles erratically and dies. cold blooded/hard to start but runs hot when warmed up.

dunno if that will be an issue on your model but lemme tell ya man, i was jazzed when i got this thing, 2600mi on a '79 CB750! the reality is, no matter how many miles it's got on it, father time will do his deed on everything that is prone to wear out. and you're going to get familiar with every system on your bike.

lots of people just let their entire carb bank sit in a vat of Pinesol for several days. seems to do wonders. you still need to run a guitar e-string through the jets to really get the gunk out though.

kirk out

VTCBike750 · « **Reply #178 on:** July 10, 2012, 05:04:26 AM »

I just wanted to follow up on the Evaporust issue. Evaporust does contain water, go to the FAQ on thier website. Basically if you leave the stuff to sit out in an unsealed jar and the water evaporates then add water.

If he just sloshed it around, let it sit over night, and then drained it maybe some of the moisture caused the minimally rusted stuff on the hump to rust more. Did he bother to clean out the tank prior to adding Evaporust? The stuff is only designed to remove rust, not varnish. Also, you said he rinsed it out, did he do anything to prevent flash rust?

VTCBike750 · « **Reply #179 on:** July 10, 2012, 05:05:10 AM »

Oh yeah, get your bike back

Trevdawg · « **Reply #180 on:** July 12, 2012, 11:06:32 AM »

Well I got the right battery. The wire coating was burnt on some of the ground wires, and looked worse than it was. So we reinsulated them. I will put the battery in this weekend and see what happens.
As for the tank .... Probably not. I'm am going to do what someone said earlier about only vinegar, drain it, water, drain it, etc.
We cleaned out the jets with one of the pipe cleaners for his welder. It fit in the jet fine and helped to unclog it.
Once the bike is at my house I will work on more things.

killersoundz · « **Reply #181 on:** July 12, 2012, 11:26:08 AM »

Hey man wow! Great score. Just my 2 cents please try to keep this bike stock!!!!!!!! In my personal opinion the only bikes you should chop up/cafe are ones that were beaters in the first place. That girl you got there is nice keep it original!

Good luck!

Stev-o · « **Reply #182 on:** July 12, 2012, 05:18:32 PM »

Now I'm not a certified mechanic but curious, how do you reinsulate wires?!

bjatwood · « **Reply #183 on:** July 12, 2012, 07:15:31 PM »

Quote from: Stev-o on July 12, 2012, 05:18:32 PM

how do you reinsulate wires?!

With a 3M wire insulator kit of course!

Stev-o · « **Reply #184 on:** July 12, 2012, 07:29:00 PM »

Quote from: bjatwood on July 12, 2012, 07:15:31 PM

Quote from: Stev-o on July 12, 2012, 05:18:32 PM
how do you reinsulate wires?!

With a 3M wire insulator kit of course!

Betting that is not how they did it.

Trevdawg · « **Reply #185 on:** July 12, 2012, 07:35:52 PM »

No it is not how we did it, lol

We put the goop/ liquid electrical tape. And then rewarp them with electrical tape. And since try we're only ground wires it was ok to be covered in black tape.

Yes!! I am keeping it original. Now that I know the rareness of these original bikes I will keep it as stock as possible.

As I said in earlier posts, I have come across an old Honda with no tank, no carbs, no seat that I'm going to start working on.

Trevdawg · « **Reply #186 on:** July 14, 2012, 04:34:26 PM »

Wires... Good
Battery... Good
No spark .... No good

We adjusted points but the spark isn't really there. Now I need new points.

Stev-o · « **Reply #187 on:** July 14, 2012, 04:45:10 PM »

Fuses?

Tews19 · « **Reply #188 on:** July 14, 2012, 05:11:57 PM »

FUSES +2!!!!!

Do you have power?

Did you fill the battery up with the acid and charge fully before trying to use?

I think you may have been able to get away with adjusting the points and merely cleaned them with a nail file to attempt to start.

Trevdawg · « **Reply #189 on:** July 14, 2012, 05:27:07 PM »

Battery is new, filled correctly an charged for over 24 hrs

Adjusted points

Will check the fuses

Tews19 · « **Reply #190 on:** July 14, 2012, 05:44:36 PM »

If wires were fried. Almost sure fuse went first

Trevdawg · « **Reply #191 on:** July 14, 2012, 05:55:24 PM »

Taillight, main, headlight fuses are all good

Trevdawg · « **Reply #192 on:** July 14, 2012, 06:00:22 PM »

Lights all work.

We have a good spark on cylinder 1&4. But no spark on the other cylinders

Stev-o · « **Reply #193 on:** July 14, 2012, 06:07:34 PM »

Quote from: Trevdawg on July 14, 2012, 05:55:24 PM

Taillight, main, headlight fuses are all good

Did you check with an ohmmeter? Cannot just visually check.

Trevdawg · « **Reply #194 on:** July 14, 2012, 08:42:13 PM »

Quote from: Stev-o on July 14, 2012, 06:07:34 PM

Quote from: Trevdawg on July 14, 2012, 05:55:24 PM
Taillight, main, headlight fuses are all good

Did you check with an ohmmeter? Cannot just visually check.

Will do

Trevdawg · « **Reply #195 on:** July 14, 2012, 09:07:46 PM »

I didn't check it with an ohm meter but we physically tested the lights and they all worked.
Do I still need to use the ohm meter?

VTCBike750 · « **Reply #196 on:** July 15, 2012, 05:59:30 AM »

If you've had any wire damage Id recommend getting a Multimeter. Plus, it will help you out a lot with these bikes. A simple electrical problem can be a complete PITA.

Not trying to sound rude or anything like that, but from the damage that your wires sustained in the pictures, Id look into redoing the whole wiring system. Not something simple to tackle. Im not there and you did say that it looked worse than it really was.

Have you checked your condensers?

ChuckG750f1 · « **Reply #197 on:** July 15, 2012, 07:54:00 AM »

Trevdawg- Did you look at the wires under the tank? You can do some swaps of common electrical parts to see if the problem follows a coil, plug wires or condenser (capacitor). Have you cleaned/checked the points? I personally would want to, at minimum, replace the wires that were damaged. IMO, I think you should start a thread in the Project area. You have a way to go and this is certainly a Project

If you don't have a multi-meter, you should get one. I use mine a lot and take it with me when I travel (not on the bike, but there are some tiny, cheap ones that would be great to have on the bike...Hmmm, I think I need 2) -Chuck

Trevdawg · « **Reply #198 on:** July 15, 2012, 02:41:08 PM »

Thanks for the info
Yes, we did clean/check the points. You can physically see one of them spark and not the other.
I will go through the owners manual and check out some of the wiring stuff. But I am glad these older bikes don't have a lot of wiring and how everything is pretty visible and you don't have to take out a lot of things to get to the wires.

Trevdawg · « **Reply #199 on:** July 16, 2012, 06:41:09 PM »

ITs ALIVE!!!

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Author Topic: Came across 1974 cb 750 that is near mint, sitting 30 yrs (Read 28787 times)