Topic: Planning CB500 rebuild

[cafehonda500]

Hello guys, Cold months are coming and I want to start planing my 71 CB500 engine build.   Bought the bike about 3 years ago but finally got it running this summer, looking to put some time and money into the engine this winter when I cant ride anyhow.   I have been reading some basics everyone like to do to their bikes such as: 650 cam, CR26 carbs, pistons, ect.   What I am looking to do is get the engine running good again with some upgrades while I am in there.   I am not looking for an insane overbore kit but have been looking at like Dynoman stage 1 or stage 2 kits, has anyone had experience with these and can tell me what would be involved?

Current upgrades include:
Dyna 5 ohm coils
new Plug wires and caps/boots
Uni air pods
Motogadget M-unit
New wire harness

My ideas for other upgrades include:
new Reg/Rectifier
New Battery
Dyna S Ignition
replacement carbs of some type as mine are very worn and need to be replaced.

Thanks for any input i can get!

[SOHC4 Cafe Racer Fan]

Cal Jeffrey (calj737) is in the middle of a 500 upgrade/restomod build.  Check out his 550/500 build threads.
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0
'75 572 Build http://forums.sohc4.net/index.php?topic=139721.0

The best performance gains from the motor will come from porting the head, a new cam (or a 650 cam swap) and increasing displacement and compression.  If you want the BEST port job available, contact Mike Rieck/JMR Porting (jmrieck2@gmail.com).  His Stage III and oversized Kibblewhite valve conversion (Stage IV) are at the apex of performance.  It will NOT be cheap, but it is worth it IF you want to optimize performance. 

You can get decent performance gains by getting a mild Stage 1 or 2 port job, swapping in a 650 cam and upping the displacement and compression with a Wiseco or Dynoman kit.

[calj737]

Thanks for the nod, Don. If it were me, (and it is) I would pursue the recipe for performance that Flatlander used (59mm pistons, re-ground cam from Megacycle 126-00 with new rockers) and stock carbs (check with Harisuluv for a new/replacement set) and then send the head to Mike. +1mm oversized valves, porting, fresh springs. Use HD studs, and away you go.

I'd steer clear of the CR-26 carbs as they will require quite a bit of tuning, unless you're knowledgeable and willing to use a shop with a proper dyno to set them up. If you do use CR-26 carbs, I'd strongly suggest you use a C5 Optical ignition (kit comes with coils, wires, and ignition plate). It allows a great level of ignition tuning to suit the performance mods.

75% of what you listed is a great "refresh" level and aside form the carbs, I think you're spot on. But I'd send the stock carbs off to Harisuluv anyway and let him rebuild them. It will be far cheaper ($400 for full rebuild with new brass) than $1200 for new CR-26s. And your motor won't justify the CR-26s unless you go after the head and cam swaps.

[SOHC4 Cafe Racer Fan]

Fair statement about the CRs. You will get a light gain from them, but not enough to justify the price without head work and a cam swap.

I would recommend the same recipe as Cal except maybe a 650 cam instead of a Megacycle. It'll save you some coin.

[cafehonda500]

Thanks for the input guys!   So the new battery and Reg/Rect are a must because mine are just worn out and need a replacement.   The reason I was thinking the CR26s is because my carbs are past repair, there are chips in it and heavy pitting.  When I last looked a set of replacement carbs were very hard to find and not cheap, but I have read about many others who had been using them.   I am not afraid of tuning and I do have a shop with a dyno I could use if needed.    Not thinking anything stage 3 upgrades (unless its the same cost lol.) 

Based on everything said would a Dynoman Stage 2 kit, rockers, ported head, and carbs be a good choice?  this combo seems to include about everything that was suggested so far.

But like I said I am just trying to plan the build at the moment, if I am completely wrong dont be afraid to tell me. 

[calj737]

It would be a nice recipe. Just confirm the spacing on the CRs is compatible with the 500 intake manifold. You can reach Godferrey (member here) he makes the CR kit I bought that is all inclusive and perfectly spaced for a 500 motor

[SOHC4 Cafe Racer Fan]

It would be a nice recipe. Just confirm the spacing on the CRs is compatible with the 500 intake manifold. You can reach Godferrey (member here) he makes the CR kit I bought that is all inclusive and perfectly spaced for a 500 motor

Now just to get that off the wood floor and running in a bike frame!!