1984 XR250R. The madness continues:-) - Page 2

Weldangrind · 10-30-2011, 03:37 AM

Rusty old thin steel doesn't cooperate well with a MIG, but a decent TIG welder might be able to patch it. In the case of my XL, I just chopped off the offending section and started again. I bought some exhaust tubing that was the correct diameter and started welding.

Weldangrind · 10-30-2011, 03:39 AM

BTW, I wouldn't be surprised to learn that a similar year XR200R muffler would be a bolt-on, if that helps to expand your search criteria.

FastDoc · 10-31-2011, 11:21 AM

Quote:

Originally Posted by SpudRider

Quote:

Originally Posted by FastDoc

Well the leaks are fixed. I was able to slightly tighten the rocker bolts and that's all it took. :P

I ground away the rotted portions of muffler. Not much good metal left!

I attempted a repair with some exhaust repair putty and some pieces of metal from a cat food can of all things. I have a feeling I'm gonna need a muffler. :wink:

It's too bad the cat food can repair didn't work. :? I bet the cat muffler would purr meowwwwwwwwwwwww! :P

Spud

I don't know, it may work! It hardened hard as a rock. I'll sand it smooth(ish) and paint it and run it till it breaks :P

Meow 8)

FastDoc · 10-31-2011, 11:22 AM

The bike is purring now. :wink:

SpudRider · 10-31-2011, 03:00 PM

Quote:

Originally Posted by FastDoc

The bike is purring now. :wink:

That's great!

It's also very fitting.

Perhaps we can now consider you a "catalytic converter." :roll:

Spud

FastDoc · 10-31-2011, 03:11 PM

Very 'pun-ny' Brother Spud!

FastDoc · 10-31-2011, 10:11 PM

I patched and painted the muffler. It looks and sounds great. No pic though...

Here's some pics of the bike where I'm at now:

Dual exhaust and dual carbs, single cylinder. Honda...

New CST rubber. :P

This is all fixed now and the newly painted muffler looks great. :P

Strong brakes. 1,000% better than The Dirt Rat's.

Remote adjustable Pro-Link suspension.

Dual carbs.

This is where oil was leaking from but thank God it was an easy fix.

FastDoc · 10-31-2011, 10:14 PM

I should take some 'After' pics now that's its all cleaned up...

Weldangrind · 10-31-2011, 11:40 PM

Regarding your brake comment, I found a donor on eBay that provided the same front end that you have. It fell into place on Son of Weldangrind's '83 XR200R; a totally worthwhile upgrade.

FastDoc · 10-31-2011, 11:51 PM

I think the brakes and the UniTrack suspension are the best improvement of the XR history of upgrades. I would have upgraded The Dirt Rat's front end had I kept it.

The Dirt Rat 2, or R2 as I call it is a worthy successor to the original Dirt Rat. More power, suspension and brakes with the same smooth ride and easy demeanor as the original. I kinda miss the electric start but the 250R starts pretty easily and has automatic compression release which helps.

Plus the absense of a electric starter and battery keeps the weight down some.

Weldangrind · 11-01-2011, 12:28 AM

I have yet to enable the electric start on Son of Weldangrind's XR200R, but I will. It feels like the kicker is going to break, because there's no compression release.

That little bike with a pushrod 230 really hauls!

SpudRider · 11-01-2011, 01:32 AM

I never heard of a single cylinder engine with dual carburetors.

Do you need to synchronize the carburetors? My guess is you don't. :?

Spud

Weldangrind · 11-01-2011, 10:08 AM

That was Honda's approach in '84 and '85, with both the XR200R and the XR250R (along with larger models). With the new four valve head, they chose to keep the two exhaust ports separate, and that style carried through to modern bikes (like Spud's XR-L). I believe that the dual carb arrangement only lasted two years, after which they created a manifold that would allow one carb to feed two intake ports.

Yes, the carbs need to be synchronized, but it's not usually critical. If it was me (and I had synchronization trouble), I'd swap to the later model manifold and one Mikuni.

FastDoc · 11-01-2011, 12:43 PM

They work like a two barrel carb on a car.

The left carb is the primary and is the only one working at low power settings. It's the only one with an enricher.

At larger throttle openings the right carb kicks in via a linkage for more mixture flow/power.

The idea is a higher mixture velocity at low power which increases tractability and torque down low. This is a priority for an XR. Then to get max power at higher RPM's the secondary kicks in.

It works well but IMHO is needlesly complex. I suspect this is why Honda did away with it after only two years.

I am fortunate my bikes carburation is currently excellent and I have no intention of messing with it in any way! :wink:

Weldangrind · 11-01-2011, 07:53 PM

I had no idea that there was a progressive transition between the two carbs! I knew about the pumper on one of 'em, but I thought they pulled at the same rate. Thanks for that detail!

10-30-2011, 03:37 AM	#16
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	Rusty old thin steel doesn't cooperate well with a MIG, but a decent TIG welder might be able to patch it. In the case of my XL, I just chopped off the offending section and started again. I bought some exhaust tubing that was the correct diameter and started welding. __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
	0

10-30-2011, 03:39 AM	#17
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	BTW, I wouldn't be surprised to learn that a similar year XR200R muffler would be a bolt-on, if that helps to expand your search criteria. __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
	0

10-31-2011, 11:22 AM	#19
FastDoc Join Date: Mar 2009 Location: Southeastern Washington desert Posts: 14,761	The bike is purring now. :wink: __________________ Happy to serve.
	0

10-31-2011, 03:11 PM	#21
FastDoc Join Date: Mar 2009 Location: Southeastern Washington desert Posts: 14,761	Very 'pun-ny' Brother Spud! __________________ Happy to serve.
	0

10-31-2011, 10:11 PM	#22
FastDoc Join Date: Mar 2009 Location: Southeastern Washington desert Posts: 14,761	I patched and painted the muffler. It looks and sounds great. No pic though... Here's some pics of the bike where I'm at now: Dual exhaust and dual carbs, single cylinder. Honda... New CST rubber. :P This is all fixed now and the newly painted muffler looks great. :P Strong brakes. 1,000% better than The Dirt Rat's. Remote adjustable Pro-Link suspension. Dual carbs. This is where oil was leaking from but thank God it was an easy fix. __________________ Happy to serve.
	0

10-31-2011, 10:14 PM	#23
FastDoc Join Date: Mar 2009 Location: Southeastern Washington desert Posts: 14,761	I should take some 'After' pics now that's its all cleaned up... __________________ Happy to serve.
	0

10-31-2011, 11:40 PM	#24
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	Regarding your brake comment, I found a donor on eBay that provided the same front end that you have. It fell into place on Son of Weldangrind's '83 XR200R; a totally worthwhile upgrade. __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
	0

10-31-2011, 11:51 PM	#25
FastDoc Join Date: Mar 2009 Location: Southeastern Washington desert Posts: 14,761	I think the brakes and the UniTrack suspension are the best improvement of the XR history of upgrades. I would have upgraded The Dirt Rat's front end had I kept it. The Dirt Rat 2, or R2 as I call it is a worthy successor to the original Dirt Rat. More power, suspension and brakes with the same smooth ride and easy demeanor as the original. I kinda miss the electric start but the 250R starts pretty easily and has automatic compression release which helps. Plus the absense of a electric starter and battery keeps the weight down some. __________________ Happy to serve.
	0

11-01-2011, 12:28 AM	#26
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	I have yet to enable the electric start on Son of Weldangrind's XR200R, but I will. It feels like the kicker is going to break, because there's no compression release. That little bike with a pushrod 230 really hauls! __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
	0

11-01-2011, 01:32 AM	#27
SpudRider Join Date: Jul 2008 Location: Idaho Posts: 25,054	I never heard of a single cylinder engine with dual carburetors. Do you need to synchronize the carburetors? My guess is you don't. :? Spud __________________ Spud "Never argue with an idiot. He will drag you down to his level, and beat you with experience." Mark Twain 2015 Zongshen ZS250GY-3 (RX3) 2006 Zongshen ZS200GY-2 (Sierra 200) 2005 Honda XR650L 2004 Honda CRF250X 1998 Kawasaki KDX220 Mods made to my Zongshen ZS200GY-2: http://www.chinariders.net/showthread.php?t=6894
	0

11-01-2011, 10:08 AM	#28
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	That was Honda's approach in '84 and '85, with both the XR200R and the XR250R (along with larger models). With the new four valve head, they chose to keep the two exhaust ports separate, and that style carried through to modern bikes (like Spud's XR-L). I believe that the dual carb arrangement only lasted two years, after which they created a manifold that would allow one carb to feed two intake ports. Yes, the carbs need to be synchronized, but it's not usually critical. If it was me (and I had synchronization trouble), I'd swap to the later model manifold and one Mikuni. __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
	0

11-01-2011, 12:43 PM	#29
FastDoc Join Date: Mar 2009 Location: Southeastern Washington desert Posts: 14,761	They work like a two barrel carb on a car. The left carb is the primary and is the only one working at low power settings. It's the only one with an enricher. At larger throttle openings the right carb kicks in via a linkage for more mixture flow/power. The idea is a higher mixture velocity at low power which increases tractability and torque down low. This is a priority for an XR. Then to get max power at higher RPM's the secondary kicks in. It works well but IMHO is needlesly complex. I suspect this is why Honda did away with it after only two years. I am fortunate my bikes carburation is currently excellent and I have no intention of messing with it in any way! :wink: __________________ Happy to serve.
	0

11-01-2011, 07:53 PM	#30
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	I had no idea that there was a progressive transition between the two carbs! I knew about the pumper on one of 'em, but I thought they pulled at the same rate. Thanks for that detail! __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
	0