Topic: 836cc upgrade- How do I know if this was done??

[Operator]

Pardon my lack of mechanical knowledge but is there any way of determining if my engine has been modified/bored out with out tearing it apart?

My curiosity is peaked now due to a few comments from a mechanic buddy of mine.

1. When he was setting the carbs he likes to give them a good once over to make sure I had cleaned them to a respectable level. During his inspection, sorry I don't know the specifics, he commented that they had been jetted.

2. He also noted when we setting the timing that it was not the stock adjustment. Again, I can't interpret his findings as I am still new to all of this.

3. Combined with a few other items such as a steering damper and performance exhaust, and the fact that I hit 130mph he thinks the PO may have done some interior work on the engine.

4. He did say there was an 836cc kit readily available for the Honda 750's a while back.

5. When he test rode it he noted that it pulled very similarly to his 73/75 Kawi 900's

As stated, I am a mechtard, I paint things not fix them, and was just wondering if any of you guys may agree or disagree with parts of his assessment.

I am not willing to do a teardown just for curiosity's sake because the bike runs great. That's why I am asking...

Thanks

Operator

[SOHC Digger]

There are only two ways that I can think of to check displacement without pulling the head:

1)  Using a boroscope and seeing if you can identify the pistons.  A cheap boroscope will run you around $60 to $80.

2)  Using oil to check volume.  Set the engine on TDC, fill the cylinder with oil through the spark plug hole (using a precise measuring cup or graduated cylinder, etc) and then rotating the engine to BDC and repeating the process.  Taking the difference between your two volumes and multiplying by four will give you your engine's displacement.  ***Make sure you get the oil back out of the cylinder***

[Sam Green Racing]

Take it to a drag strip, if it runs 13.5 seconds, it's stock. If it runs low 12s, it's a big un.

Sam.

[voxonda]

Or just run it on a Dyno. Tells you enough.

Cheers, Rob

[Sam Green Racing]

Not as much fun though Rob.

Sam.

[voxonda]

How should I know? Have never dragraced. 

Rob

[Operator]

Digger, thanks for the techniques, the oil volume one sounds like a good one to try just before I put the bike up for the winter. At least it will have a good coat of oil on the internals for when the snow flies.

Rob, excuse my ignorance but how will a dyno tell me if it's modded, or does that just tell you of you are putting out above stock hp?

Sam, screw all this tech crap...I like your idea. I just want to go to the municipal airport and race planes up and down the runway.

All kidding aside, once again, I asked a question and learned something......i love this forum......thanks gents

Operator

[voxonda]

Hey operator,

A dyno will tell you what power the engine delivers, but what is more important, how and when it makes its power. A 836 will not make that more top end but considerable more mid-range.

Cheers, Rob

[Sam Green Racing]

I still think my idea was best but the Miramichi drag strip will be closed now, should have asked your dumb question earlier in the year, look how much fun you've missed.
Is that your bike in your avatar?  looks nice, any better pictures.

Sam.

[Operator]

better picture

[754]

Check the valve clearances, should be bigger if it has a cam. Hope  no one set them back to stock, if it has a cam.
If it has unknown cam, better find/check the clearance specs and record them..

[CBJoe]

better picture

That is a very slick looking bike.... 

[Operator]

Thank You....

The only thing I would like to change is to go back to an original seat

I am also in the process of mounting Krauser hardbags (70's era ones) and a Dunstall style fairing that originally came off of a CBX. Looking for a little more comfort for the long trips. Both will be easily removable.

[754]

you may want to consifer changing sidecover emvblems to 72 &71  script versions, they will fit.. and 72 headlight ears if you like chrome, no holes for the signal stems.. really would look nice..

[Don R]

That looks like a K-F hybrid, might have a custom seat. what do you think, 77-78F with a k tank, rear fender and trim? Rear disc,  black fork legs and dual disc front yet a K look.  Oh, I just saw where it says 73, very cool and a lot of time invested in placing the best parts from many years on one bike!

[the technological J]

i say find someone who has a stock 750 take it out for an hour then take your bike for a ride that should be a good indication of whether or not u have more power or not

[Operator]

That looks like a K-F hybrid, might have a custom seat. what do you think, 77-78F with a k tank, rear fender and trim? Rear disc,  black fork legs and dual disc front yet a K look.  Oh, I just saw where it says 73, very cool and a lot of time invested in placing the best parts from many years on one bike!

Here is the rundown on what has been changed from the original 73K.

-Custom seat,
-Forks, Comstar wheels and brake system from a 78F. Original tank badges were broken during removal and were replaced with the F badges. Looking to go back to originals if anyone has got a couple laying around.
-4-1 Vance and Hines/Honda aftermarket exhaust system.
-Steering Damper
-Throttle Lock
-Not sure of where the handlebars and mirrors came from but they are nice and comfortable for long trips.


Personally I love the mixture of the two models. I am a huge fan of both the K and F's. A couple of the "purists" here have criticized the hybrid style but they are not the ones riding it.

Thanks for the interest!!

[Don R]

Well, I like it a lot! there are many styles and I can appreciate most of them. I found an old extended fork customized K1 recently and although it's not my style I can't stop thinking about buying it and leaving it as a period piece bike.