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Discussion Starter #1
I'm looking to buy a '78 CB750 supersport with 35k miles on it. Gave it a ride this weekend, and other than shaky idle on start up it looks and sounds decent. I'd appreciate any opinions on whether I can expect any big future mechanical jobs on this engine with 35k miles on it. Incidentally, owner is asking $2,300 for it. Thanks for any input.
 

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Who knbows? It all depends on how well it was taken care of in the last 35k miles.
 

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Who knbows? It all depends on how well it was taken care of in the last 35k miles.
 

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Yes, how well it was taken care of does matter. But 35k on an aircooled bike engine is 35k on an aircooled bike engine, no matter how well it was taken care of.

At that mileage, I would do one of two things: 1) get a compression test, and send a sample of oil to a testing lab; or 2) just figure it may be good for a few more years, but will soon be due for a rebuild, and buy it at a price that accounts for that.

There, that's my amateur advice, from a guy who has never owned a CB750. More experienced CB750 folk will be along soon to add some actual reliable information.
 

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Yes, how well it was taken care of does matter. But 35k on an aircooled bike engine is 35k on an aircooled bike engine, no matter how well it was taken care of.

At that mileage, I would do one of two things: 1) get a compression test, and send a sample of oil to a testing lab; or 2) just figure it may be good for a few more years, but will soon be due for a rebuild, and buy it at a price that accounts for that.

There, that's my amateur advice, from a guy who has never owned a CB750. More experienced CB750 folk will be along soon to add some actual reliable information.
 

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first off - too much money.

Second - 35K on a 77-78F is the tipping point. You will want to know if the bike had valve guides installed. The 77-78 SOHC big valve heads tend to wear out valve guides right around 30K. Less if it was beaten, a little more if it was taken care of. At 35K, and it is not smoking, you probably have 1 or 2 thousand miles before she starts smoking, and when she does it is an expensive repair if you don't do it yourself. Ask the owner if new valve guides were installed, if they were then great.

The rest of the engine is good for 75-100K if you take care of it and there is not something nasty hiding in there already.
 

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first off - too much money.

Second - 35K on a 77-78F is the tipping point. You will want to know if the bike had valve guides installed. The 77-78 SOHC big valve heads tend to wear out valve guides right around 30K. Less if it was beaten, a little more if it was taken care of. At 35K, and it is not smoking, you probably have 1 or 2 thousand miles before she starts smoking, and when she does it is an expensive repair if you don't do it yourself. Ask the owner if new valve guides were installed, if they were then great.

The rest of the engine is good for 75-100K if you take care of it and there is not something nasty hiding in there already.
 

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Discussion Starter #10
Geeto, I'm over the border in Nassau County. Do you have any pix of your bike for sale?
 

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Discussion Starter #11
Geeto, I'm over the border in Nassau County. Do you have any pix of your bike for sale?
 

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quote:Originally posted by bc66

Geeto, I'm over the border in Nassau County. Do you have any pix of your bike for sale?
Good thing cuz the bike is in Nassau County at my father's place.

no pics. I have it on the lift to do a few clean up items. If you are serious, send me an email off board and we'll chat.

out of curosity, what was the bike you are going to look at?
 

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quote:Originally posted by bc66

Geeto, I'm over the border in Nassau County. Do you have any pix of your bike for sale?
Good thing cuz the bike is in Nassau County at my father's place.

no pics. I have it on the lift to do a few clean up items. If you are serious, send me an email off board and we'll chat.

out of curosity, what was the bike you are going to look at?
 

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Steve is telling ya right.....

oil is everything

If it's been changed religiously.....as in every xmas and easter..... it's subject to be running junk.

Good oil faithfully and treated better than family..... it could easily have many good miles left.

I wouldn't bank on it if you aren't looking at a stack of aviation anal retentive type logs and hearing all the tales from the guy who worshipped it.

Primary chain..... listen. Walk if you can hear it. Turn the idle down as slow as the engine will idle.

Very few of them are worth the effort and expense of replacing them however many holeshots later it takes to stretch them.
 

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Steve is telling ya right.....

oil is everything

If it's been changed religiously.....as in every xmas and easter..... it's subject to be running junk.

Good oil faithfully and treated better than family..... it could easily have many good miles left.

I wouldn't bank on it if you aren't looking at a stack of aviation anal retentive type logs and hearing all the tales from the guy who worshipped it.

Primary chain..... listen. Walk if you can hear it. Turn the idle down as slow as the engine will idle.

Very few of them are worth the effort and expense of replacing them however many holeshots later it takes to stretch them.
 

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The cb750 clutch is a noisy piece of kit that is easily mistaken for the sound of the primary chain. Stock you should hear a sound like truck truck truck that goes away when you pull the clutch in.
 

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The cb750 clutch is a noisy piece of kit that is easily mistaken for the sound of the primary chain. Stock you should hear a sound like truck truck truck that goes away when you pull the clutch in.
 

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Discussion Starter #18
Geeto, for some reason my last post didn't post...I tried emailing you, but as a noob I don't rate a direct email to a Dahlia Lama. My direct email is on my bio page.

The bike I was looking at is a '78 CB 750 supersport.
 

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Discussion Starter #19
Geeto, for some reason my last post didn't post...I tried emailing you, but as a noob I don't rate a direct email to a Dahlia Lama. My direct email is on my bio page.

The bike I was looking at is a '78 CB 750 supersport.
 

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quote:Originally posted by bc66

The bike I was looking at is a '78 CB 750 supersport.
whose 78 CB? As a self professed know it all, if it was in the NYC area there is a good chance I know the bike if not the person.

I'll e-mail ya.
 
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