Topic: cb750 Hard Tail & siezed Eng.

[Wolf]

hello everybody....

New to the forum and cb750's

ive got a couple of questions maybeyou might have some answers

I picked up a hard tail frame and im not sure what year its off and the only thing i have to go off is the vin. i asked dmv and they have no history on the vin. Is there a way i can find out through the vin what year it is?
vin # is cb750 1112102

my other question is I have an 1978 CB750 that i just recently picked up and im assuming the engine is siezed because i put a new battery and it just clicks and the kicker is stuck and will not move.


any info any one can give would be great.

THANKS in advance

[ekpent]

Frame looks to be a 1971.

[Alan F.]

Try the search function, look for the term stuck engine and you'll find tons of useful info.
Oh and welcome.
Alan F.

[754]

Posting your location is a good idea.. may be help a few blox away...

[Wolf]

thanks ekpent i suspect its pre 76'

Alan F i did a search and it seems everybody who has a similar problem had a running bike then it got stuck so all the help seems to be about stuck chain ect...

thanks 754 ill do that

[SOHC Digger]

How about a picture of this frame for the curious?

[KingCustomCycles.com]

Soak all 4 cylinders with ATF for at least 3 days.  Try to unstick it with turning the rear wheel in 2nd gear.  Kickstarter has very little leverage.  Next, remove the stator cover and try to turn it with a strap wrench and a length of pipe.  If all this fails, part it out.

[MCRider]

A hard tail frame with a VIN? I thought they were all after market frames and didn't really come with a VIN. So if it had a VIN on it, was it removed from a stock frame and riveted onto the hardtail?  So the VIN tag may be off a 71/K1, but it could have been put on anytime.  For purposes of getting a plate, you could use the VIN.

What I'm getting at is that it really doesn't have a year of its own, its whatever the builder wants to call it.

OCICBW

[754]

if you weld a rear section on, it is a hardtail frame. If it is a full frame, then it would be a custom rigid frame... in which case, it should not have stock numbers.. if it is legal.

[MCRider]

if you weld a rear section on, it is a hardtail frame. If it is a full frame, then it would be a custom rigid frame... in which case, it should not have stock numbers.. if it is legal.

Ah, didn't think of a weld on rear part to the stock front.

[KingCustomCycles.com]

It is, and was common to transfer the numbers from a donor bike to a full custom frame ?? Legal? all day long.

[Stev-o]

I too just bought a 750 with a "stuck engine:

Do this:

1. Mix a jug of ATF & acetone, 50/50.
2. Pour a generous amount in ea cylinder, leave plugs out.
3. Let it set at least 3 days.
4. Then put trans in 3rd gear and rock back & forth. You'll know if it "unsticks", the fluid will shoot out! [I have the record, 18'!]
If yes, then try kickstart - hard!

If no, put more ATF/acetone in cyl and let set for 3 more days and try again.

This method really works! Good Luck.

[754]

Legal..surely you jest..
 name one place you can legally transfer OEM numbers to a non stock frame.. If it can be done anywhere, it would , mean surrendering, and destroying stock frame..
 Do you think there is no law enforcement that can tell the difference between factory and custom frames..?

[The_Crippler]

Legal..surely you jest..
 name one place you can legally transfer OEM numbers to a non stock frame.. If it can be done anywhere, it would , mean surrendering, and destroying stock frame..
 Do you think there is no law enforcement that can tell the difference between factory and custom frames..?

I can't speak for everywhere, or possibly even bikes, but I know that this is common practice with hot rods - they even allow it in NY (where I grew up) which is surprising.  As for surrendering the stock frame...it just means that frame doesn't have a VIN any more and isn't titleable.

Of course, this also is how stolen vehicles get resold - swap VIN plates with a scrapped vehic with a clean title, and away you roll.  Yes, it is a loop-hole, but one that works for legal custom vehic makers and criminals alike.

[754]

 That is a tag swap, Hondas have the number stamped in the frame. At the moment you stamp these numbers into another frame, you have a clearly illegal frame.. How can 2 frames have the same number legally?

[dave500]

any tell tale on the spark plugs?follow the advice on putting oil down the spark plug holes,itll help with the engine dissembly at least if you cant get it turning nicely by hand.

[KingCustomCycles.com]

That is a tag swap, Hondas have the number stamped in the frame. At the moment you stamp these numbers into another frame, you have a clearly illegal frame.. How can 2 frames have the same number legally?

Destroy the first (donor) frame.  There are thousands of Choppers in service that have done this.  It will pass police inspection.

[The_Crippler]

That is a tag swap, Hondas have the number stamped in the frame.

I see what you are talking about.  I hadn't thought of that - only the riveted on tags.

[KingCustomCycles.com]

I too just bought a 750 with a "stuck engine:

Do this:

1. Mix a jug of ATF & acetone, 50/50.
2. Pour a generous amount in ea cylinder, leave plugs out.
3. Let it set at least 3 days.
4. Then put trans in 3rd gear and rock back & forth. You'll know if it "unsticks", the fluid will shoot out! [I have the record, 18'!]
If yes, then try kickstart - hard!

If no, put more ATF/acetone in cyl and let set for 3 more days and try again.

This method really works! Good Luck.

I would be careful not to leave the acetone in the crankcase for an extended period of time.  It will swell seals and strip the protective oil and varnish coating from engine internal parts. 

[Stev-o]

I too just bought a 750 with a "stuck engine:

Do this:

1. Mix a jug of ATF & acetone, 50/50.
2. Pour a generous amount in ea cylinder, leave plugs out.
3. Let it set at least 3 days.
4. Then put trans in 3rd gear and rock back & forth. You'll know if it "unsticks", the fluid will shoot out! [I have the record, 18'!]
If yes, then try kickstart - hard!

If no, put more ATF/acetone in cyl and let set for 3 more days and try again.

This method really works! Good Luck.

I would be careful not to leave the acetone in the crankcase for an extended period of time.  It will swell seals and strip the protective oil and varnish coating from engine internal parts. 

The acetone will evaporate rather quickly.

[KingCustomCycles.com]

I too just bought a 750 with a "stuck engine:

Do this:

1. Mix a jug of ATF & acetone, 50/50.
2. Pour a generous amount in ea cylinder, leave plugs out.
3. Let it set at least 3 days.
4. Then put trans in 3rd gear and rock back & forth. You'll know if it "unsticks", the fluid will shoot out! [I have the record, 18'!]
If yes, then try kickstart - hard!

If no, put more ATF/acetone in cyl and let set for 3 more days and try again.

This method really works! Good Luck.

I would be careful not to leave the acetone in the crankcase for an extended period of time.  It will swell seals and strip the protective oil and varnish coating from engine internal parts. 

The acetone will evaporate rather quickly.

I believe acetone is an active ingredient in seafoam and other fuel and oil additives.  I would not count on evaporation when it is mixed with ATF.

[Retro Rocket]

Yep, acetone is not good any where near rubber seals inside the engine, making them swell and making them softer, causing them to give way under pressure and it will strip oil off everything it touches. Put your rubber manifolds into acetone and it really softens them up.

Mick