Topic: AmateurHour890_duncwerks

[scottly]

From the looks of the counter-shaft, that is not a K7 motor; the K7 seal area protrudes out from the engine case, and the K7 shaft doesn't have the groove for the sprocket retainer. What serial # is on the engine case?

[dunc]

Hey scottly! Thanks for jumping in... the number on the casing is CB750E-2225159.

[dunc]

From the looks of the counter-shaft, that is not a K7 motor; the K7 seal area protrudes out from the engine case, and the K7 shaft doesn't have the groove for the sprocket retainer. What serial # is on the engine case?

Hey scottly! Thanks for jumping in... the number on the casing is CB750E-2225159.

[scottly]

I think the number makes it a K3 engine? You will need a 10mm off-set front sprocket to line up with the K7 rear sprocket.

[dunc]

I think the number makes it a K3 engine? You will need a 10mm off-set front sprocket to line up with the K7 rear sprocket.

I checked the numbers myself and looks like you and I both came to a K3 Engine. I was wondering how it got painted black -  assumed it was original and removed to be serviced and such then painted but looks like someone swapped this in at some point. Anyways now that that's cleared up.

I do have a cognito offset front sprocket and a spacer for the rear if needed.  The bike was fully assembled when I got it and it rolled fine.

Any other enigmas with the K3 Engine?

Also are K Heads interchangeable? I have some busted fins I'd like to address.

_dunc.

[754]

K heads from 73 to 76 will look the same.  I think they added knock pins or sleeves around 74.
 You should be able to make it work.
 I would pull the head if you can and see.

[Yamahawk]

Hi Dunc,
   Your project is looking good, should be a great bike when you get done!
Charlie

[dunc]

So got some progress going on. Got a new to me set of 78 carbs in from Pat out in Toledo (awesome transaction). An ultrasonic cleaner . And a better condition K3 head with close to perfect fins.

I'm looking to completely go through the engine at this point and the CYCLE X Git Kits are pretty tantalizing. Particularly the #2 Full kit which includes...


<sup>-Wiseco 836cc Piston Kit .... Forged 10.25 compression ratio.
-Cycle X Super Rods ........  Upgrade to ARP bolts for racing.
-Clutch Plates ........ Many racers around the world prefer our friction plates.
-Heavy Duty Springs ..... Kibblewhite performance springs.
-Cam Chain ................... Wearable item that needs replacement.
-Heavy Duty Cylinder Studs ....... The best in the industry. (Check tech page)
-Camshaft CX1, CX2, CX3, KHD CX1 ..............Drop-in performance cams.
-Valve Set  ..................... Stainless with nitride coating.
-Valve Guides ................ Kibblewhite cast iron guides. (The best)
-Gasket Set .................... Complete gasket set with upgrades mentioned below.
- MLS Head gasket and No Leak Valve Cover Gasket Upgrade. (See gasket tech page)
-Oil Seal Set  .................. You need these.
-Primary Chains ............... Another wearable item that needs to be replaced.
-Primary Chain Tensioner .... Discontinued from Honda. (Our version is better anyway)
-Cam Chain Slider ...................... Wearable item.
-Cam Chain Roller ...................... Wearable item.
-Cam Chain Roller Assembly ...... Wearable item.
-Adjustable Cam Chain Sprocket ... Chains stretch. You can readjust your cam timing back to the previous setting after X amount of miles.</sup>

For the low price of around 1900... The biggest thing that pushes up the price of this kit is the rods offered so I have to ask - how much of a plus are these rods compared to stock (granted I were to get the crank balanced along with the stock rods).

Anyone have experience with these kits or better to piece together one myself?

- dunc

[dunc]

Also got my little shop space coming together here. And got the swingarm bushings out. Got to love a blow torch and some rod stock.

[dunc]

So got some progress going on. Got a new to me set of 78 carbs in from Pat out in Toledo (awesome transaction). An ultrasonic cleaner . And a better condition K3 head with close to perfect fins.

I'm looking to completely go through the engine at this point and the CYCLE X Git Kits are pretty tantalizing. Particularly the #2 Full kit which includes...


<sup>-Wiseco 836cc Piston Kit .... Forged 10.25 compression ratio.
-Cycle X Super Rods ........  Upgrade to ARP bolts for racing.
-Clutch Plates ........ Many racers around the world prefer our friction plates.
-Heavy Duty Springs ..... Kibblewhite performance springs.
-Cam Chain ................... Wearable item that needs replacement.
-Heavy Duty Cylinder Studs ....... The best in the industry. (Check tech page)
-Camshaft CX1, CX2, CX3, KHD CX1 ..............Drop-in performance cams.
-Valve Set  ..................... Stainless with nitride coating.
-Valve Guides ................ Kibblewhite cast iron guides. (The best)
-Gasket Set .................... Complete gasket set with upgrades mentioned below.
- MLS Head gasket and No Leak Valve Cover Gasket Upgrade. (See gasket tech page)
-Oil Seal Set  .................. You need these.
-Primary Chains ............... Another wearable item that needs to be replaced.
-Primary Chain Tensioner .... Discontinued from Honda. (Our version is better anyway)
-Cam Chain Slider ...................... Wearable item.
-Cam Chain Roller ...................... Wearable item.
-Cam Chain Roller Assembly ...... Wearable item.
-Adjustable Cam Chain Sprocket ... Chains stretch. You can readjust your cam timing back to the previous setting after X amount of miles.</sup>

For the low price of around 1900... The biggest thing that pushes up the price of this kit is the rods offered so I have to ask - how much of a plus are these rods compared to stock (granted I were to get the crank balanced along with the stock rods).

Anyone have experience with these kits or better to piece together one myself?

- dunc

Still looking for feedback on rods or not to rods and general pointers on what's a good budget performance setup. Such as is an undercut transmission worth it too?

[dunc]

I know there's got to be some people that can chime in on this here ^

[dunc]

PM me if you don't want the F tank.  In my opinion, they have better lines.

Sending you a PM - going to be fabricating my own tank going forward

Also scored up some of these pretty shoes for the sled. And am "polishing" some parts.

[dunc]

Tedious, but worth it.

Still need to add a slight chamfer to each. Did both my front rotors and the idiot in me didn't change the pattern from left to right. So that'll look a little funny.

It's amateur hour somewhere.

[dunc]

I have this wonderful and awful habit of searching craigslist in the sub $1000 bracket in the counties surrounding los angeles. Well this one may of worked out. A gentleman in So Cal is clearing out his private shop space and I needed some parts. I went down there to get (at the least) some period finned side covers. And ended up leaving with a little more.

So now it looks like I'm building a 890cc 10.25:1 engine.

I'll be carrying over internals from my K3 engine, transmission (would like to get an undercut unit), crank, oil pump, and such.

Anyone have a recommendable Cam Shaft for hot and hard street use? Looking to get a good spec sheet to finish out this engine

And the rabbit hole continues, cheers lads.

[madmtnmotors]

Magic windows! Sweet! 

[754]

Sweet, did you get the 890 rods or lower end.
836 is often ok with stock rods, 890m you better get stronger rods..
 What else did he have ?

[scottly]

Anyone have a recommendable Cam Shaft for hot and hard street use? Looking to get a good spec sheet to finish out this engine

I've heard good things about the Megacycle 125-75 grind on the Hi-Po section. Check out Sparty's bike that CBJoe just bought..

[dunc]

Sweet, did you get the 890 rods or lower end.
836 is often ok with stock rods, 890m you better get stronger rods..
 What else did he have ?

No rods (yet). The upper case is modified to fit the 890s. As well as windows ground out between 1/2 and 3/4 cylinders. Definitely going to be need some stronger rods now - any suggestion for the bang for the buck? CycleX, APE, or?

The guy had a whole world of parts. From K0/1 oddities to this set of Solex carbs with manifold, filter, rebuild supplies... he's a member on here but not active lately. Been around amassing "unobtainium" parts for 30 years and looking to clear house. Be happy to pass along contact info via pm.

[dunc]

Anyone have a recommendable Cam Shaft for hot and hard street use? Looking to get a good spec sheet to finish out this engine

I've heard good things about the Megacycle 125-75 grind on the Hi-Po section. Check out Sparty's bike that CBJoe just bought..

Awesome, I'll check out their builds. Sending your finances tomorrow

[CBJoe]

Anyone have a recommendable Cam Shaft for hot and hard street use? Looking to get a good spec sheet to finish out this engine

I've heard good things about the Megacycle 125-75 grind on the Hi-Po section. Check out Sparty's bike that CBJoe just bought..

I'm not sure...but I don't think you can get that specific grind anymore.  Cycle X offers the CX-7  http://www.cyclexchange.net/camshaftpage.htm  with this description "Similar to the Mega Cycle 125-75 but with 3 more degrees of duration. We found this cam to work well with 915cc kits and above."

[dunc]

I'm not sure...but I don't think you can get that specific grind anymore.  Cycle X offers the CX-7  http://www.cyclexchange.net/camshaftpage.htm  with this description "Similar to the Mega Cycle 125-75 but with 3 more degrees of duration. We found this cam to work well with 915cc kits and above."

Hey CBjoe!

That's the one I was looking at just now. Should be solid paired with some RS34s, I think it's fair to say that the 78pd carbs aren't up to the task now.

[CBJoe]

I'm not sure...but I don't think you can get that specific grind anymore.  Cycle X offers the CX-7  http://www.cyclexchange.net/camshaftpage.htm  with this description "Similar to the Mega Cycle 125-75 but with 3 more degrees of duration. We found this cam to work well with 915cc kits and above."

Hey CBjoe!

That's the one I was looking at just now. Should be solid paired with some RS34s, I think it's fair to say that the 78pd carbs aren't up to the task now.

Probably not   Maybe I missed on the earlier post...but what's the state of that head?  Were the whole barrels and top end an RC deal?

[dunc]

Probably not   Maybe I missed on the earlier post...but what's the state of that head?  Was the whole barrels and top end an RC deal?

I didn't go into much specifics. It's been ported and polished pretty extensively from what I see, also see photos above (admittedly, I'm no expert). Combustion chambers are also smoothed and each been measured. I know that it was all built to be a set kit just never fully assembled. The name Mike Verduga was thrown out when I asked who did the head work.

I'm going to inquire for more specifics from the seller on where it came from exactly and when.

[dunc]

The scoop on the engine parts in his own words.

"Regarding the motor... I can only tell you what I know: Mike Verduga saw a Craigslist ad for an RC Engineering-built "Cobra" motor in San Francisco. It wasn't cheap but he bought it. As it turned out, it had the Arias 890 pistons, three good RC steel street rods, extremely high lift drag class cam, with the rest being essentially stock. He went through the motor to the condition you've seen, ported the head, purchased new piston rings and, when he was going through closing his business due to divorce, sold the engine parts to me. That's really all I know, Duncan. Essentially, it is what it is."

And there ya have it.

So I have my eyes on...

- CX-7 cam.
- Stainless Steel Valves
- Heavy Duty Valve Springs
- Rockers (unsure)
- Rods (unsure)
- Undercut Transmission from CycleX
- Lighten and balance crank / alternator
- Mikuni RS34s (pods or custom stacks with filter box/element/thing)
- Heavy Duty head studs.

Any leads on parts is appreciated.
None of this is in the immediate budget but hey this is supposed to take time right?
This hole first bike rabbit hole is getting deeper and deeper.

- dunc

[SOHC4 Cafe Racer Fan]

So I have my eyes on...

- CX-7 cam.
- Stainless Steel Valves
- Heavy Duty Valve Springs
- Rockers (unsure)
- Rods (unsure)
- Undercut Transmission from CycleX
- Lighten and balance crank / alternator
- Mikuni RS34s (pods or custom stacks with filter box/element/thing)
- Heavy Duty head studs.

Any leads on parts is appreciated.
None of this is in the immediate budget but hey this is supposed to take time right?
This hole first bike rabbit hole is getting deeper and deeper.

- dunc

I'm sending you a PM.