Willard's vintage Hotsaw Builds

[Steve]

Myself thinking we're going for the long haul with the Covid 19 thing, here is the start of my 3rd bikesaw project to keep me occupied.
514 cc 91mm big bore 1984 Honda CR500R . Air cooling fins will be milled off after running in the bottom end bearings and new rings. Will save alot of weight there.
Engine profile will be cylinder leaning ahead like how it is in the bike.
Big heavy engine. No problem getting 70hp at the crank with the right squish, ignition, pipe and carb with porting tweaks.

View attachment 263027 View attachment 263028

That is going to be sweet!

 

[Willard]

Well I bet everyone is biting at the bit wondering what's coming up next in this thread.

I can finally do a mock up profile pic of my 1984 Honda CR500R 514cc bikesaw project.
Big thankyou to Nathan aka BigMac for shipping me a crankcase and spare newer cylinder head.
Couldn't do this without you brother!!
Now to start the cutting, R&D and building, will have it in the wood next summer. Hot start with single cut big wood.
Still have 2 other bikesaws to finish.

 

[Time's Standing Stihl]

Any predictions on when any of them will see wood?

 

[Willard]

Any predictions on when any of them will see wood?

Yes I'm pumped to see these saws in the wood too, but I'm holding back hacking and rushing the builds for testing at the moment.
Presently I recently had cataract surgery and going for the other eye next month. Gotta take it easy lifting and being around dust.
But the pay off now is that my vision is amazing from what it was makes the delays totally worth it.
Like looking through a clean window, Lol.
My brain is not working as good as it did when I built my first bikesaw 37 years ago...but today's artificial intelligence internet sure is helping making up for it, Lol!!

Taking my time, presently working at the bead blasting cabinet cleaning all the cases, cylinders, heads. Then fresh rebuilds with OEM parts.
Then top and rear handles, trigger mechanisms.
Should have my modified jet ski carbs shipped in from southern California any day now.

 

[Willard]

Besides I want my projects to outlast this Covid19.
Reason why I started a CR500 project

 

[Stihl working Hard]

Well I bet everyone is biting at the bit wondering what's coming up next in this thread.

I can finally do a mock up profile pic of my 1984 Honda CR500R 514cc bikesaw project.
The short rod OEM crank with Crankworks billet Pro Rods kit came in tonight.

Big thankyou to Nathan aka BigMac for shipping me a crankcase and spare newer cylinder head.
Couldn't do this without you brother!!
Now to start the cutting, R&D and building, will have it in the wood next summer. Hot start with single cut big wood.
Still have 2 other bikesaws to finish.
View attachment 264748 View attachment 264749 View attachment 264750 View attachment 264751

Nice looks parts there wow wiseco make a sexy piston cranks not bad either

 

[Willard]

Nice looks parts there wow wiseco make a sexy piston cranks not bad either

Yes this crank is special, I bought it from one of the top CR500 builders in the world.

Yes Honda did things right with their CR500 piston designs. They all fit from the 1982 CR480 right up to the 2001 CR500.

 

[Willard]

Got 2 very expensive Honda NOS cranks here up for comparison.
1983 CR250R crank in the fore ground, 1984-2001 CR500 in the back.
Both share the same main bearings and same PTO spline for the sawchain sprocket.
And that bearing needs to be pressed onto the journal, not glued on with Loctite 680 like the spare used cranks need done to them.

 

[Bigmac]

Yes this OEM/ CW billet rod crank is special, I bought it from one of the top CR500 builders in the world.

Yes Honda did things right with their CR500 piston designs. They all fit from the 1982 CR480 right up to the 2001 CR500.

Got 2 very expensive Honda NOS cranks here up for comparison.
1983 CR250R crank in the fore ground, 1984-2001 CR500 in the back.
Both share the same main bearings and same PTO spline for the sawchain sprocket.
And that bearing needs to be pressed onto the journal, not glued on with Loctite 680 like the spare used cranks need done to them.

View attachment 264916

I want to add, that the 480/500 pistons changed through the years, and not all weisco’s are the same. The newest offer is universal, but it has not always been that way, the older prolite’s had a different side reliefs, and the Honda and pro-x pistons are different still. The old piston worked great on the 480/ air cooled 500 with the oval exhaust port, the 85-01 port with the bridge puts some of the older Designs at their limit, the pro X piston has barely 1 mm of clearance on each side of the bridge to exhaust port making modifications impossible without short circuiting the transfers out the exhaust, the new Wiseco offering is superior to all previous designs.
Great looking cranks! That cw short rod is awesome! And just to clarify on the main bearing fit, it should be a light press fit on both webs, but you install the bearings in the cases first and then pull the crank into each case half to install, that’s how the book calls it. And if you freeze the crank the pto side will slide into a warm bearing, the stator side will always need pulled if the crank is new, or in excellent shape. And another sidenote aftermarket main bearings even made by the same manufacturer as OEM, a.k.a. Koyo) Have different tolerances than OEM packaged main bearings, something to look at when doing repairs

 

[Willard]

Thanks Nathan for the info.
I've been following a few CR500 forums actually about six. Lots of stories about those certain pistons causing short circuiting.
These new Wiseco teflon pistons are nice, one builder said he allows more sidewall clearance for them.

Those main bearings in the cases you sent me are like brand new, still tight and roll really smooth.
So if they are factory original I hate to disturb them and their pockets.
I bought a small roll of really expensive 4 inch wide rubber duct tape to fix my portable shed tarp.
I'll pull out the seals and cover up those bearings in the cases with that tape cut in circles to fit.
Then I can bead blast and do the cutting and milling on the cases without dirtying up the bearings.
Plus save me C$120 not having to buy them from the dealer.

 

[Bigmac]

Still admiring these carbs. How's this for flow blending on this 40mm?
View attachment 268112

What dose the od of the bell measure? Looks nice

 

[Willard]

What dose the od of the bell measure? Looks nice

The outside diameter is 71 mm , nice snug fit for the 6" Uni snow pod filter rubber flange.

 

[Willard]

Just figured out the reasoning of the Stihl 19mm bar nuts other then same size as the spark plug versatility on a scrench.
Work great for double nutting bar studs. They grip tight!
Installing MS880 studs on one of my bikesaws.

 

[Willard]

My case splitter for the bikesaws finally came in, now just waiting for the Motion crank puller.





BTW the '82 YZ125 and '84 CR500 share the exact same head studs.
The '83 CR250 and '84 CR500 share the exact same cylinder base studs.

 

[Willard]

Well it looks like we're still in the long haul with this Covid so I'm just taking my time making parts from a pile of parts.
Spring is still 4 months away up here so I'm sure looking forward to hitting the wood.

Just did some repairs on the bead blaster cabinet tapering down from 1/2" to 1/4".
The carbon fiber plate for the CR500 came in , went high gloss 3K plain weave. Very strong plate will definitely need it for the 500.
Got the cases down south for welding repairs and modifications.

 

[CR888]

How does one go about pull starting a CR500 bikesaw? ....big spring in the elastostart handle? One handed pressups or auxiliary electric starter motor?

 

[Willard]

How does one go about pull starting a CR500 bikesaw? ....big spring in the elastostart handle? One handed pressups or auxiliary electric starter motor?

There is a thing you use on top of your shoulders CR888 jk...

Two decompressors and not chainsaw ones.
My CR250R bikesaw will be all the power I'll need. The CR500R is just backup when the going gets tough, Lol.
With todays aftermarket parts and companies specializing in CR500's and into the bigger bore kits the versatility of the CR500 is pretty well endless compared to what we had 10- 15 years ago.

There is already big bore 250 Hondas putting out 70 plus h.p.
Just a walk in the park capability for a 500

 

[Willard]

Getting my parts ready for polishing, but still a bit more bead blasting to do.
I'm modifying the blaster cabinet by converting the media suction pipe and connection's to 1/2" inch.
Less plugging and better flow with my 1/2" air line supply.

So this my corner of the side bench with 20"×20" box fan downdraft table and with a squirrel cage fan above it to cleanup more air in the my little shop.
Also got a 5hp shop vacuum exhausted through the floor to suck out dust close to the work piece.

Here I got a dedicated 8" grinder for polishing aluminum and a Foredom cable grinder for porting.
Outside at 1 PM its sunny and -32C and 3 feet of snow on the ground.
Here inside the shop a balmy 70F.

 

[Willard]

I took a break from the projects and did about a month of interior house painting, worked out nicely recharging some thoughts on the bikesaws.

Picked this up this morning for $48 USD on sale. An addition to my other various carbon fiber cutting tools.
Will work nicely on the big sheet of high gloss CF for the CR500R.
Also got an interesting experimental sawchain build project for the 500. It will throw some serious chips and no modifications to the chassis whatsoever.

 

[Willard]

So 12 years ago I bought this media blaster cabinet thinking I was going to rebuild old vintage saws.
Just used it for the first time this year and I'm not building vintage chainsaws
#3 Glass media sure strips the paint nicely. Also heard it shot peens the parts too helping relieving some internal stresses.
Going to blast some #7 glass bead next to give the parts a little shine cleaning them up nicely.