Author Topic: Andys CB810 K2 -updated 14 Oct 2024 - missing link! (Read 93630 times)

bwaller · « **Reply #125 on:** April 17, 2011, 05:01:35 PM »

Thanks Andy for restoring my faith in humanity. It's just great to know you are so responsible in not speeding out there.

Will watch for your Dyno session.

andy750 · « **Reply #126 on:** April 23, 2011, 11:55:24 AM »

Thanks Brent I like to try my best

andy750 · « **Reply #127 on:** April 23, 2011, 11:55:37 AM »

CB750K2
55,000 original miles on the bike

Mike Rieck (JMR) engine:
Bored out to 810cc
Dynoman 295 cam
Ported

Stock carbs
120/40 jets
Stock airbox/OEM air filter
Stock clutch
Oil - regular 10W40 Penzoil - not changed since rebuild.

Added 2 gallons of Ultra 93 on the way to the dyno which mixed with the regular 87 I normally use.

Dyno was done personally by Rick Stetson at Harrys Machine Shop in Northborough. Rick is a world famous drag racer and has a little plaque as you walk in saying he is a member of the 200 mph club! Another plaque says 222.2 mph!! So he jumped on the K2 and did the dyno...was fun to watch...and the result is (in 4th gear)....

Before the second run (blue line) the bike was strapped down at front and back as the rear wheel was slipping - turns out the rear wheel is either not balanced or out of true - its way out apparently! Anyway on the second run the clutch slipped - you can see where....so possibly a few more HP when the wheel is sorted out.

So powerband is between 5000 -7000 rpm which is exactly where i have been feeling it on the highway.

Rick did mention the initial lag on the throttle due to the stock carbs so CV carbs or something else would eliminate this.

Very happy with the numbers! Thank you Mike!!

cheers
Andy

bwaller · « **Reply #128 on:** April 23, 2011, 01:43:32 PM »

That's great Andy. Considering all the stock parts to keep it streetable, well done.

It's just too bad we all never think to make a couple pulls on a dyno beforehand for comparison.

andy750 · « **Reply #129 on:** April 23, 2011, 02:44:33 PM »

Thanks Brent and I agree about the before comparison. I was thinking about that today on the road home in the pouring rain. Before I had the engine work done it would still pull pretty well at 70 mph even with a leaky head gasket. The K2 is a different bike compared to the K4 thats for sure.

I also noticed the rear wheel more now that someone else has mentioned it! So glad I did the high speed run last week

. Next thing for this bike is rear wheel sorted out, new rear shocks and swingarm bushings sorted out, front suspension - progressive springs.

cheers
Andy

MRieck · « **Reply #130 on:** April 23, 2011, 02:55:29 PM »

I witnessed "the event".

Several things would have added 3 to 4 more HP. 1...better clutch springs, 2, an oil change prior to the run. 3, A rear wheel in spec and a better rear tire. The bike sounded good on the dyno.....I was 6 feet away but doing some other business. I'd like to say the pistons in the engine are very old Wiseco's that I couldn't get the top ring for anywhere. I went through a big process of installing a ring "spacer" etc, etc, etc. I don't want to talk about that as it was a PITA. Anyway....it was a top end build that turned out nice. I'm very happy Andy went to the dyno...in the pouring rain I'd add (hard Scott he is)

Remember that on a good day these engines had 50hp or so. When you start getting 80hp with only a 30% increase on displacement keep it in mind.

MRieck · « **Reply #131 on:** April 23, 2011, 02:58:04 PM »

Also....nice torque for an 810.

andy750 · « **Reply #132 on:** April 23, 2011, 03:57:03 PM »

It shows the quality of a builder when he turns up to see what the dyno will do. Mike had predicted 74 - 75 hp on this engine when he was building it and given the improvements he suggested above I think this engine will achieve that. So as usual he is right on the money!

Once again thanks Mike for all your hard work on this engine! It really shows when riding it. This bike really puts a smile on my face every time I ride it.

Many thanks
Andy

Jerry Rxman Griffin aka MuthaF'er · « **Reply #133 on:** April 23, 2011, 04:11:46 PM »

Mike just simply kicks ass

Now we need to see what the addition of one of his famous Stage IV heads will do to that graph

Come on Mike, loan him one for the day! You know he'll buy it once he sees what it will do

Retro Rocket · « **Reply #134 on:** April 23, 2011, 04:53:22 PM »

Nice numbers Andy......

azuredesign · « **Reply #135 on:** April 23, 2011, 06:46:18 PM »

Are you going back Andy after making the revisions Mike was speaking about? It'd be good to see if you can pick up a few ponies just doing maintenance stuff.
Good job!!

andy750 · « **Reply #136 on:** April 23, 2011, 07:27:33 PM »

Yes Ill go back Ben - its def worth it. You should join me next time

knowsnothing · « **Reply #137 on:** April 23, 2011, 07:48:54 PM »

Nice work andy. Looks like you have a little wrenching to do in your near future

Ps - what a crap day

andy750 · « **Reply #138 on:** April 23, 2011, 08:07:26 PM »

Quote from: knowsnothing on April 23, 2011, 07:48:54 PM

Ps - what a crap day

Yes thats what i was thinking speeding down the outside lane of the Mass Pike this morning....

jaguar · « **Reply #139 on:** May 01, 2011, 11:33:33 AM »

nice #
glad to see the bike coming along

Hinomaru · « **Reply #140 on:** May 01, 2011, 12:55:44 PM »

Very nice HP and TQ numbers and a testament to your engine builder.

For a comparison, I had my former K2 on a dyno jet back in '95 and it pulled 49 HP and 37 TQ. It was a un-molested bone stock bike with 38,000 original miles.

andy750 · « **Reply #141 on:** May 01, 2011, 07:54:20 PM »

Thank you for that info Hinomaru as it would have been nice to have done a pre-dyno run. Ill go with your numbers! My K2 has 55,000 miles - engine is like new now.

thanks
Andy

andy750 · « **Reply #142 on:** May 08, 2011, 05:24:04 AM »

Yesterday it was sunny in the morning with temps in the low 70s. So I took the K2 over to Ashland, MA to see MikeR who would be helping me fit the new Honda clutch plates and Barnett spings that he had ordered for me during the week.....by the afternoon it was raining like crazy with large hail coming down hard resulting in local flooding and the temps dropped to 55F. Welcome to New England weather!!

Ben (Azuredesign) was also there at MikeRs School of CB750 mechanics

sorting out his defective Dyna 2000 and seeing if his monster hot rod 750 would run - it did and it sounded great!

Anyway...pulled the K2 clutch (55,000 miles, stock clutch) and discovered the fiber plates were worn almost to nothing and the clutch basket itself (piece with the 4 posts) had really bad corrosion -MikeR - "I have never seen this so bad before!" - meant that yet again Andy750s K2 was giving him lots of interesting things to discover

Lucky for me MikeR has a couple of spare engines lying around and he very very generously pulled a fresh looking basket from one of them....after much prep on the new plates (soaking them in some top quality Repsol oil), bead blasting the steel plates, bead blasting the basket....we installed new clutch....wow what a difference! Not stiff to pull at all as I had feared but smooth, precise shifting.

We also pulled the rear wheel and checked it for trueness....yes we confirmed that it had a significant side-side wobble...with no wheel experts in the area it looks like its time for a new wheel. Thinking about going big and going for the Sunrims from Buchanan.

Another great day at MikeRs school of CB750 mechanics and Mikes never ending patience and attention to detail. Great way to spend a rainy Saturday afternoon in the garage.

The ride home along the Mass Pike was in heavy fast moving traffic in the rain so it was a good testing ground for the new clutch which performed flawlessly....and I was also very conscious of the crappy handling from the back end especially on the off/on ramps in the rain...need that new wheel asap!

cheers
Andy

MRieck · « **Reply #143 on:** May 08, 2011, 07:25:04 AM »

Always fun and ...interesting

.......Nice to solve some problems with good company.

azuredesign · « **Reply #144 on:** May 08, 2011, 07:52:57 AM »

Kudos, thanks, & happy muthas day to Mike!

andy750 · « **Reply #145 on:** January 07, 2012, 02:01:28 PM »

New Years update - with temps almost hitting 60F on the 7th January I took the chance to get the rebuilt swingarm (thanks Hondman) back on the K2 and install the Hagon 2810s with the new 26 kg springs. Wow what a difference!! Head shake at 40 mph is gone!! Finally! Bike feels very planted in the corners and accelerates smoothly up to the ton with big grins all around. This bike is so different from the K4 I was riding last week. The accelaration, the throaty HM300s and the general hooligan nature of it make it a very fun bike to ride. 60 mile loop with a mixture of backroads and highway made this a good ride today.

Pre-swingarm rebuild- lots of movement in the rear and headshake at 40 mph. Thats all gone now and Hondaman has done another fine job. Also the Hagon 2810s are feeling better and better after the spring change (thanks to David Quinn for changing them so easily even after 6 months had passed).

cheers
Andy

hoodellyhoo · « **Reply #146 on:** January 07, 2012, 08:57:27 PM »

Glad to hear the bike keeps getting better and better

Emokid · « **Reply #147 on:** January 08, 2012, 04:22:40 AM »

Quote from: andy750 on January 07, 2012, 02:01:28 PM

New Years update - with temps almost hitting 60F on the 7th January I took the chance to get the rebuilt swingarm (thanks Hondman) back on the K2 and install the Hagon 2810s with the new 26 kg springs. Wow what a difference!! Head shake at 40 mph is gone!! Finally! Bike feels very planted in the corners and accelerates smoothly up to the ton with big grins all around. This bike is so different from the K4 I was riding last week. The accelaration, the throaty HM300s and the general hooligan nature of it make it a very fun bike to ride. 60 mile loop with a mixture of backroads and highway made this a good ride today.

Pre-swingarm rebuild- lots of movement in the rear and headshake at 40 mph. Thats all gone now and Hondaman has done another fine job. Also the Hagon 2810s are feeling better and better after the spring change (thanks to David Quinn for changing them so easily even after 6 months had passed).

cheers
Andy

Didnt see this thread until now , what a great looking , and i guess performing bike , congrats on a super build

will have to read through all of this now

andy750 · « **Reply #148 on:** April 13, 2012, 06:32:38 PM »

Thanks to forum member Knowsnothing for polishing my spare tank...now the K2 810cc is almost complete. Just waiting on the new petcock then I can dazzle in the sunshine...

Sidecovers are by Frankenstuff

cheers
Andy

brandEn · « **Reply #149 on:** April 13, 2012, 06:51:37 PM »

your bike rules. I love it.

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Author Topic: Andys CB810 K2 -updated 14 Oct 2024 - missing link! (Read 93630 times)

Hinomaru