Topic: Has anyone installed a 605cc kit into a 500/F motor?

[kjr4honda]

Apart from the obvious engineering that needs to be done to stuff it in, what other mods did you make to the motor to liberate the ponies? I am building a GP-spec (push start only) race motor out of a CB 500 Four donor.

So far I have gas-flowed the head, matched the exhaust ports to the pipes (2-into-1's), installed a Webcam race 55-371 cam, race-spec cam chain, stiffer clutch springs, installed over-size valves, removed the starter motor assemby (and the starter gear) as well as the complete kick start mechanism and shaft, knife-edged the crank and had the whole crank assembly balanced.  29mm carbs are on the shopping list.

Have I missed anything?

[Mr.Paynter]

Hi There,

I have less than little knowledge on the engine-works although I am working on that slowly as I am cleaning upa 73 CB500 Four.
Sounds like she is going to be a beast! How're things progressing?

Also, who if I may ask is doing all of your engine work?

I am starting some cleaning/polishing/general work soonish (in process of moving house) and I have sourced some parts and bits I need which is great but whilst the bike was running when I got it, it is rough and hasn't been looked after so I'd like to find someone with the knowledge to go through the engine and make sure she's all sorted and I am willing to pay etc. trustworthy mechanics here (in KZN) seem to be like hens' teeth!

Any advice would really be appreciated!

[kjr4honda]

Mr Paynter,
sorry about the delay in replying - got involved with the 24 Hour Endurance race held the other weekend.  I do all my engine work myself - except for the engineering.  Takes a lot longer but I know that the result will be what I expected, not botched by some "expert".  Read all the CB500 threads on this site - they are a great source of info.  I have done some of the work/mods described in these threads and it is all good.

[Terry in Australia]

I've installed the "605" (actually 592cc) kit in a 550, they only come with single piece oil rings, but they do come with new sleeves for the 500.(not needed on the 550) 29mm CR carbs are way too big for a 500,(or even a 592) go for the 26's, or your bike will run like shiite. Cheers, Terry.

[kjr4honda]

Thanks Terry.  Had the new sleeves installed quite recently, have yet to bolt it all together again.  One of the local HMG (historic motor group) guys runs the 602 kit and has nothing bad to say about it.  Smaller carbs now penciled in.

[Terry in Australia]

No worries mate, the pistons are fine, but some folks here think that single piece oil rings are the devil. I've had them in my 836 for years and I think they're fine. Cheers, Terry. 

[kjr4honda]

Some people just don't like change, I guess.

[Terry in Australia]

No, what happens is that one of the resident "experts" will say that 3 piece oil rings are good, and the gathered masses will take that to mean that single piece oil rings are bad.

The guy who's 550 engine I built was so worried about it that he paid me to modify his pistons to take 3 piece rings. Totally unnecessary, but I couldn't convince him otherwise. Cheers, Terry.