What's on your bench?

[Bigmac]

Hey Mac , I was looking for your TrX thread.
Yep it's a 1983. The birth year of the CR250R up to 2001. No power valve, porting looks the same as the CR's in the 1990s.
I picked that year because it's the last year they had right hand ignitions which my YZ125 has and I want to build them both the same profile which works for me. PVL ignition makes them run reverse rotation so I can get the b/c on right hand drive.
Arlen and Chris at LED make beautiful pipes and that's who'll make mine for both saws.
I'm running Boyesen Pro Series carbon reeds on both factory reed cages with stoppers deleted. Would like to try a ESR v force 3 series on the CR250 but I think the Pro series with a ported factory cage is all I need.
Crank works will true and weld the pin on the crank along with a new ProX rod and bearings.

In the last month I've learned a ton about the cr250r, very impressive engine.

Here is a link to that thread

http://opeforum.com/threads/1986-trx250r-build-thread.15671/

 

[Willard]

Led build some nice pipes indeed! With porting head work and pipe you could get into the low to mid 40hp range with the 250cc pretty easy, the 330 should hit 50hp reliably and be easy to start, less compression, and have a wide power cure. the oem cage isn’t bad, the 01 cr cage with 07 reeds is supposed to support 50+ hp. A stock 01 is 47-48hp. Looking forward to the build!

Thanks, from my research the '83 CR250 had stock 43 hp at the crank and it was only running a 36mm carb. I haven't talked to the guys at LED yet but from their FB page the owner has a fondness for vintage Cr250's. From what I see the port work they do it's pretty amazing with the extra transfers etc. They just port a new sleeve and press it in. I'm sure for enough dollars they can do the same to my '83 cylinder. You have any idea how much a big bore these early cylinders can handle?
I know there was a factory 350 big bore in the mid 1980s for the 250, called a Mugen or something like that.

 

[Willard]

Here is a link to that thread
http://opeforum.com/threads/1986-trx250r-build-thread.15671/
http://opeforum.com/threads/1986-trx250r-build-thread.15671/

Thanks for the link, will be a good read!

 

[Bigmac]

Thanks, from my research the '83 CR250 had stock 43 hp at the crank and it was only running a 36mm carb. I haven't talked to the guys at LED yet but from their FB page the owner has a fondness for vintage Cr250's. From what I see the port work they do it's pretty amazing with the extra transfers etc. They just port a new sleeve and press it in. I'm sure for enough dollars they can do the same to my '83 cylinder. You have any idea how much a big bore these early cylinders can handle?
I know there was a factory 350 big bore in the mid 1980s for the 250, called a Mugen or something like that.

The later CR’s can go 295, I don’t know on the 83, the head stud location were the limiter on the later cylinders. The 84-86 maybe even tell 89 cr bottom end will fit the trx cylinder I believe, and the trx big bore cylinder is a bolt on, I don’t know about the 83. I have wanted to build a vintage big bore 85, but that’s a ways off! An oem cylinder at 68-69mm bore can be vary potent have seen many at 50-55 hp to the wheels on a trx. Good porting goes a long ways on these with a good pipe and reeds!

 

[Willard]

Good porting goes a long ways on these with a good pipe and reeds!

LED has been building cr250 hot saw pipes for a few years now and even building their own hotsaw.
When I get the saws finished up I'll get ahold of LED about porting my '83 cylinder along with a fresh bore job and new single ring piston plus a new cone pipe.
I can case match the cases to cylinder as I don't want to send the whole saw off to them.
I will get the head done by them at the same time as I'll send them the 3 pieces of solder squish samples.
I ordered two 3120XP decomp valves to install in the head.

What's winning at the Stihl Timbersports recently is a LED/ESR cr330, but there's probably $10K put into it.
Not in my plans All I want is 50hp at the crank direct drive sprocket and have a reliable manageable saw to have fun with.

 

[Bigmac]

LED has been building cr250 hot saw pipes for a few years now and even building their own hotsaw.
When I get the saws finished up I'll get ahold of LED about porting my '83 cylinder along with a fresh bore job and new single ring piston plus a new cone pipe.
I can case match the cases to cylinder as I don't want to send the whole saw off to them.
I will get the head done by them at the same time as I'll send them the 3 pieces of solder squish samples.
I ordered two 3120XP decomp valves to install in the head.

What's winning at the Stihl Timbersports recently is a LED/ESR cr330, but there's probably $10K put into it.
Not in my plans All I want is 50hp at the crank direct drive sprocket and have a reliable manageable saw to have fun with.

Good plan, it’s going to be a fun build. Arlan is a good r builder, that cylinder with the exception of the head stud pattern is really similar to a trx, the pipe flange looks the same so that should be helpful. At the crank you should hit your goal! I have seen there hot saws on the web, his shop is an hour and a half away from me. That should be a hell of a hot saw! If you did the equivalent to a drag port it would be reliable in your use and get some good rpm’s! Keep us updated!

 

[Willard]

Good plan, it’s going to be a fun build. Arlan is a good r builder, that cylinder with the exception of the head stud pattern is really similar to a trx, the pipe flange looks the same so that should be helpful. At the crank you should hit your goal! I have seen there hot saws on the web, his shop is an hour and a half away from me. That should be a hell of a hot saw! If you did the equivalent to a drag port it would be reliable in your use and get some good rpm’s! Keep us updated!

One good thing about my '83 head is it's got 7 studs ('84 has the same) which should be good for a tight seal.
Yes I was thinking drag port too, on Facebook I saw Arlan removed the exhaust bridge out of a vintage Cr250 and works good with a proper chamfer better then the '84 oem cr250 did with its bridge less exhaust port.
If you have a cr250 crank laying around with just the con rod and no main bearings, could you weigh it? I'm curious because I weighed my '83 crank and it weighs 7 lb 8 oz.

 

[Bigmac]

One good thing about my '83 head is it's got 7 studs ('84 has the same) which should be good for a tight seal.
Yes I was thinking drag port too, on Facebook I saw Arlan removed the exhaust bridge out of a vintage Cr250 and works good with a proper chamfer better then the '84 oem cr250 did with its bridge less exhaust port.
If you have a cr250 crank laying around with just the con rod and no main bearings, could you weigh it? I'm curious because I weighed my '83 crank and it weighs 7 lb 8 oz.

I only like to remove the bridge if there is damage, or the cylinder has sub-Exhaust port or triple ports, with the bridge you can widen the exhaust a lot with the bridge, with sub-exhausts there is plenty of width , I haven’t had any issues even with a wide port as long as the bridge is relived properly, but on the esr big bores I like the big bridge less port with sub exhausts. The 01 cylinder is the most desirable cr cylinder, it is bridge less and has sub-exhausts.

I will do some digging on the crank I know I have trx cranks but I will have too look

 

[Willard]

Thanks, In 1984 the cylinder went bridge less but went back to the bridge in '85.
Also in '84 the Cr250r went full circle crank with full tin can stuffer. My '83 has 2 smaller stuffer plates... was just wondering if '84 on the cranks were lighter then my 7lb 8oz one.

 

[Willard]

I'll have to start a thread rather then tie up this one....
Here's my crank 1981-1983 design, takes the same con rod kit up to 2001. Looks more stout then the newer tin can ones without the tin can plus a much heavier mag side stub too.

 

[drf256]

Playing 361 Squeal

 

[redlight066]

Al I assume you’re using HSS to get a finish that slick. Nicely done. Pic of the cutter profile please.

 

[Billy Currie]

I put the final touches on the replacement saw of the one that was stolen from my shop a few months back. Now to pass it on to the owner in the morning.

Yeah, it's kinda hard to follow up that bike engine ain't it Doc? LOL Nice machine work as usual!

 

[Bigmac]

461 dropped off this morning Tank and full wrap coming

 

[Ronie]

Jonsered 630 getting a 268 cylinder. I messed the cylinder up a little and it still needs some work.

 

[USMC615]

Does dicking around with Colt, Ruger, and S&W AR-15’s count? And managed to sharpen four EDC knives...two Kershaw’s and two Browning’s!

At least I got something accomplished today other than half-chickens on the grill and knocking down cold ones...

 

[Bilge Rat]

Nice gun vises, i like the adjustable cradles.
Aircraft mechanics tend to keep things neat, organized.
My FIL worked P38s in New Guinea during WW2 then Delta In the New Orleans shop for 38yrs.

 

[USMC615]

Nice gun vises, i like the adjustable cradles.
Aircraft mechanics tend to keep things neat, organized.
My FIL worked P38s in New Guinea during WW2 then Delta In the New Orleans shop for 38yrs.

The Tipton Ultra gun vises also have middle inserts that lock into the front/rear body rails like the sliding parts trays...allow you to magazine well an AR-15/AR-10/M-4. The Ultra’s are well worth the coin. Can get ‘em for $130 and some places are crazy high for the Ultra vise. I paid $104 for the second new one...just happened to catch it on Amazon with Prime free two-day ship. Damn sure wasn’t gonna turn it down for that.

 

[Bilge Rat]

Those are nice.
For the M-4 having it supported by the mag well keeps everything accessable.
Having your work solidly supported makes everything easier/ better.
The price is reasonable, if i put my 6k custom bolt gun in something to work/clean/check it i want solid safe support so my work is done right.

 

[huskyboy]

There good saws, stick with the non - mtronic one if you decide to get one. A bit easier to work on. Cheaper carb parts. Coil is unlimited too I believe.

Not unlimited! This particular one cuts out at around 13 ish on the tach. Found that out today lol. Does anyone know if some 441 had a unlimited coil or were they all limited?