Is it easy to confirm a bike has a big bore kit installed?

[Buck]

Hi, I'm new to the forum and excited to learn and start tinkering with a vintage bike.

My question is, I'm going to check out a 76 CB this weekend that the owner claims has a big bore kit installed. Is there an easy why to confirm that it's got the big bore kit?

The bike has been sitting for 10 plus years so I don't have details as to when it may have been installed. All I have currently are some random cell phone pics. I'm hoping to see it today or tomorrow.

Thanks

 

[amc49]

Not that easy. Look for signs top end has been apart like non-OEM gasket sealing or in plug hole with flashlight to look at piston top. Still no guarantee even then.

Try to trip owner up, if he knows a big bore kit is there then he can tell you the size, brand, compression, etc. Not knowing tells the tale, they all say that.

Many say that but fewer are real. Quick way to sell bike fast that is missing in many other aspects, the testosterone kit. Sitting for 10 years is your issue there, look harder at that. The kit if installed may be a butcher job, so many of them are. Myself when buying, I prefer NOTHING like that be installed; it is often the mark of death. I prefer OEM parts not messed with, POs do enough damage to things on the OUTSIDE of a bike, I want them nowhere near the insides.

 

[Buck]

@amc49 Thanks, those are good points. I'll definitely push the guy a little.

From the pictures I've seen it looks fairly untouched other than the exhaust and his big bore kit claims. Problem is he's got the "I know what these damn bikes are worth" attitude.... we shall see. Thanks again

 

[dirtdigger]

a lot will depend on the maker of the bore kit...no name kit wont be worth anymore then a stock engine, if you have RC ENGINEERING parts then it would be worth more money just because they are worth a fair amount on the used market. If its just a 836 kit then its not really worth anymore then stock IMO. Look for a different stamping on the cylinder(front of cyl1 at the bottom by the case) some builders used to grind of the 736 and stamp the new size, if its from RC it will be stamped RC ENG. Also look for silicone between the cylinders at 1and 2 and at 3 and 4, people would pack it full to stop oil leaks on really big bores. Also look for any stamping on the cylinder head, normally on top fin of the head at the back between cylinder 2 and 3 if its RC. More then likely its just a cheap small 836...no big deal. I agree, if he knows its a big bore he should be able to tell you about it.

 

[amc49]

'Problem is he's got the "I know what these damn bikes are worth" attitude....'

That has truth stretching all over it, you have already picked up on it...............everybody thinks his is 'the best'. Yet sitting to biodegrade for 10 years. What's wrong with that? Call him out on it. Politely of course.

 

[Buck]

@dirtdigger, thanks for the info I'll give it a good look for identifying marks.

@amc49, I'm planning on checking it out this afternoon so we'll see. I figured on top of sitting for as long as it has, the possibility of a mystery/unidentifiable big bore kit and that I'll also have the DMV to deal with I should have some good ammo for negotiating with him.