Willard's vintage Hotsaw Builds

[Willard]

How's the vibration on a saw like that?

Don't know yet about the CR250R but the YZ125 has virtually no vibration whatsoever. When you get into the big bore I hear vibration can be a problem.

Mailman just dropped these off , it's like Christmas almost every other day.
CR250 crank primary drive gear pieces to rig up the hub for the 15 tooth .404 sprocket.
CR250 Top end gasket set for rebuilds down the road , complete set still on it's way.
Sure nice to see these gaskets are made in the USA, not China !!

 

[Willard]

Don't know what I should do about this NOS 1983 CR250R crank listed on Ebay for $500 ($660 Canadian)
Too bad I already bought a crank that needs rebuilding.

 

[Mastermind]

Very cool thread gents. Thanks for posting !!!!

 

[Willard]

Very cool thread gents. Thanks for posting !!!!

Thanks again to Bigmac for offering his knowledge and experience on these engines, this wouldn't be a thread without his input!

 

[Steve]

Thanks again to Bigmac for offering his knowledge and experience on these engines, this wouldn't be a thread without his input!

Thats why im following along. Nathan knows his stuff on these. He can build a mean 2 smoke bike!

Production chainsaws are dumb!

 

[Bigmac]

Here is a port timing calculator, can be fun to play with and is handy if you don’t have your piston yet
https://lambretta-images.com/tuningh/port-timing-calculators/

I use them all the time

 

[spencerpaving]

Don't know yet about the CR250R but the YZ125 has virtually no vibration whatsoever. When you get into the big bore I hear vibration can be a problem.

Mailman just dropped these off , it's like Christmas almost every other day.
CR250 crank primary drive gear pieces to rig up the hub for the 15 tooth .404 sprocket.
CR250 Top end gasket set for rebuilds down the road , complete set still on it's way.
Sure nice to see these gaskets are made in the USA, not China !!
View attachment 207361

Awesome project....But a 250 should turn a 16 tooth without a problem....

 

[spencerpaving]

Forgot to add.....My cr125 saw turns a 14 tooth .404.....I run reg .404 on it......404 high tooth makes it work pretty hard...

 

[Willard]

Awesome project....But a 250 should turn a 16 tooth without a problem....

Thanks for your input Spencer.
I believe the cr250r will handle a 16t .404 no problem but next summer I hope to race the Honda at Squamish, B.C. They run 22" Douglas fir there, damn tough wood so I thinking 15t .404 with the 46RST HT chain.
I'm shopping for two of these GB harvester. 404 rim's in 15t and 16t
They look super light and strong but I can't find any available in North America, so probably have to order out of Australia.
What do you think?

 

[Willard]

Here is a port timing calculator, can be fun to play with and is handy if you don’t have your piston yet
https://lambretta-images.com/tuningh/port-timing-calculators/

I use them all the time

Awesome Nathan, thanks!
What have you heard about the ESR CR250 flat head and dished piston setup?
It's supposed to be the best thing since sliced bread.

 

[Bigmac]

The c.e.o setup is still pretty new, I have been following it closely. One available since June, I have heard decent things, I think is more for roll on power honestly, ktm did it back in 88-89ish so if the it didn’t catch on then makes me wonder. I like the new e2b cylinder, that’s and improvement in its self. Carlos at bdt built a couple and felt it was to early to tell. Setup is so important on any of these, have seen so many motor that are dogs because of the wrong base gaskets or timing or squish. I would like to try one, I really want that 81mm bore e2b cylinder, the cool thing is it’s only a piston and dome swap in my current setup to try, more low end and better response would be nice, But I don’t need the power valve once you get over 350cc, there is plenty of torque at that displacement. To me it’s not worth $400-500 more to try

 

[Willard]

Here's the ESR 310 CEO advertised. Interesting concept.

 

[Bigmac]

Here's the ESR 310 CEO advertised. Interesting concept.
View attachment 207452

It is interesting, I also would like to try the trx10 pipe, Hand coned, but $600 just to see, I would like a few more people to try first! Lol the bdt pipe is totally custom and hand coned for $800

 

[Willard]

It is interesting, I also would like to try the trx10 pipe, Hand coned, but $600 just to see, I would like a few more people to try first! Lol the bdt pipe is totally custom and hand coned for $800

The CEO Ktm design from the 1980's was thought thru but I think economics played a role then. Today with computerized CNC ESR may have potential. I heard his cylinder caster died earlier but sounds like their making their own now.
I'm definitely going to get one of $600 cone pipes from LED for the Honda.
The '82 YZ OEM pipe I got working pretty good over the years. All apart now ready for welding for this build. Not a permanent pipe but good enough for now and breaking in the new internals.

 

[Bigmac]

The CEO Ktm design from the 1980's was thought thru but I think economics played a role then. Today with computerized CNC ESR may have potential. I heard his cylinder caster died earlier but sounds like their making their own now.
I'm definitely going to get one of $600 cone pipes from LED for the Honda.
The '82 YZ OEM pipe I got working pretty good over the years. All apart now ready for welding for this build. Not a permanent pipe but good enough for now and breaking in the new internals.
View attachment 207453 View attachment 207454

The hard thing with the custom pipes are if you make changes, like going big bore of significant port changes you could be less than optimum. I wish esr would dyno the ceo vs there standard cylinder so people could see. Same with there trx5 -9-10 pipes it would really help the public. Have seen a lot of dyno comparisons with the trx5 pipe against almost everything, have seen no more 3 hp on the top, and they usually lost 2-3 under peek. Bdt I clamming 3 more everywhere over the 5, but haven’t seen a dyno to prove it, have a friend the has installed 2 and the customer we’re happy, but he didn’t dyno them. I would also like to try the led team g big bore pipe, have a buddy that has one, and it isn’t crazy impressive, it’s a 330 with race gas v3’s and a 39mm carb, my 350, will walk on him by 4 bike lengths in a 100 yards, and I have 70 pounds on him. Everything has to be matched

 

[Willard]

Good points.
I'm 99% sure whoever builds my pipe will also do everything I want done to the cylinder and head also.
Also nice to have a pipe with adjustable header pipe but just adding or removing gasket spacers should be enough., stinger pipe I can easily adjust on my own.

 

[Willard]

Just delivered from OEM Cycle all the way from Tennessee.
What a thing of beauty...Mikuni Super BN 38mm gas carb.
Weird thing thix brand new carb came wrapped up in a nest of paper in a cardboard box not sealed in a plastic no instructions or anything.
Holding off on the second carb, going to see if it's too much for the YZ125 or just right. Next step up is 42mm
Too big it'll hurt ne in the cold start into a log. Races are lost that way.
There's a alcohol version available.

 

[Bigmac]

I am running a 38mm on my 363cc, guys are making 170hp with twins on alky and 41mm carbs, bigger isn’t always better on carbs, I have jumped up from 36 to 38mm and gained everywhere too, it kinda depends, I usually favor the little smaller

nice looking carb!

 

[spencerpaving]

Thanks for your input Spencer.
I believe the cr250r will handle a 16t .404 no problem but next summer I hope to race the Honda at Squamish, B.C. They run 22" Douglas fir there, damn tough wood so I thinking 15t .404 with the 46RST HT chain.
I'm shopping for two of these GB harvester. 404 rim's in 15t and 16t
They look super light and strong but I can't find any available in North America, so probably have to order out of Australia.
What do you think?
View attachment 207451

I like the looks of those!!

 

[Willard]

I like the looks of those!!

If you find any let me know.