1993 Honda XR 250 R Full Restoration

[Moto7man]

Another build coming along. I was wanting something more simple for extremely tight wooded single track. Low seat height, air cooled no radiators, smooth power, low maintenance and super reliable.I have had the YZ400 F, CRF 450s etc but I am really a two stroke guy so I am not so sure how this is going to work out.

Here is the old girl, she has been in storage for a long time. She turns over but won?t start. She has spark,fuel but the compression is too low,50 PSI per my gauge. So, I am going to start by pulling the head,cylinder for inspection, then send out head,cylinder to be bored for a new Wossner piston and all new Honda gaskets.I think the subframe and foot pegs are a little tweaked as well.Yikes, look at that stock silencer?. it?s as big as a boat anchor.

 

[(F5)]

I do enjoy your restos. I might struggle with the subject matter having valves and cams, but will see the transformation as what it is I bet.
RM still looks great lurking in background.

 

[Moto7man]

Thanks! I am struggling with the valves and cam stuff too.

 

[Moto7man]

Ok, I per her at TDC per the Honda Manual and removed the valve cover confirmed the timing marks on the cam sprocket were lined up. Here is a picture of the inside of the valve cover, everything looks good. She looks really clean inside, no metal, oil had drained out clean.

Here is the head at TDC, It?s very clean, I have to check the valve adjustment, .1 mm on intake and .12 on the exhaust.

 

[Moto7man]

I went ahead and removed the sprocket cam bolt, then rotated the crank 180 degrees and removed the other sprocket cam bolt, then removed the cam sprocket and the cam shaft and bearing noting that the sealed side of both bearings face outward.

Everything going along well and I removed the head bolts and head.

The piston didn?t look too bad, it is a Honda KT1, but I don?t see an indication if it is a std, a .25 or a .50.

 

[Moto7man]

Here is the piston,

Side shot of the cylinder,

This is where we are so far, however I have a problem, I have removed all the head bolts without a problem, it is a mix of 12mm and 8mm but I cannot break the cylinder loose. Does any one have any ideas?

 

[Gasser Nate]

Double check all the bolts are out and if so a CAREFULLY place block of wood and a few taps with a hammer will break the gaskets hold. Those stock Honda gaskets get a good bite in over time on air cooled motors. But make sure you try to not hit the fins as they are extremely brittle.

 

[(F5)]

Extreme Violence.

Worst that can happen is that you will give the ghost of Soichrio a double hernia. And that prick kinda deserves it.

 

[Moto7man]

LOL,maybe?

 

[webmaster]

FYI

http://www.lt-racing.com/html/xr250r_s.html

Les and I have been riding xr250s since 1987....

I would go with a J & E piston versus the wossner. Although a Honda oem 1985 xr250r piston 4th overbore is a good alternative ( if it is still available).

Your other option is to pick up a sleeve and piston 80mm from thumper racing to go to 300cc. The cases will need to be split and bored to accept the larger sleeve.

Best pipe back in the day was a white brothers magalloy.
The stock pipe with the baffle removed has good power...

For carb, I would stay away from from cheap kits that use 2 stroke carbs.

Stock cam works best for woods.

Jeff

 

[Moto7man]

FYI

http://www.lt-racing.com/html/xr250r_s.html

Les and I have been riding xr250s since 1987....

I would go with a J & E piston versus the wossner. Although a Honda oem 1985 xr250r piston 4th overbore is a good alternative ( if it is still available).

Your other option is to pick up a sleeve and piston 80mm from thumper racing to go to 300cc. The cases will need to be split and bored to accept the larger sleeve.



Best pipe back in the day was a white brothers magalloy.
The stock pipe with the baffle removed has good power...

For carb, I would stay away from from cheap kits that use 2 stroke carbs.

Stock cam works best for woods.

Jeff

Thanks Jeff!

 

[Moto7man]

I post a heat gun on the cylinder then put a piece of wood on left side and tapped it lightly with a hammer, then the other side and it broke loose, it took a couple of minutes.

 

[Moto7man]

Here is the cylinder,

Crank is in good shape,no excessive play.The crank and the internals are super clean and no debris, no marks, looks new inside.I think this may be the original piston.

 

[webmaster]

That is an oem piston...

Jeff

 

[(F5)]

Ahh, well I see the problem. They've left the ports out of the cylinder in the manufacturing process! Really quite an omission. Bit of an effort with the rotary tool should fix that. Don't forget to do a crankcase pressure test to make sure they haven't made any errors there as well.

Might want to check the Piston for ring pegs, I don't see any.

 

[Moto7man]

Lol, I wish it was as easy as working on my gasser. But it's not too different.

 

[farmerj]

Jeff, fun to see the work that you & Les did. What's the magic of the 250 vs. the XR400?

Obviously, I have not ridden either!

Had an XR200 around at one point though, as I recall.

Jeff

 

[webmaster]

Jeff, fun to see the work that you & Les did. What's the magic of the 250 vs. the XR400?

Obviously, I have not ridden either!

Had an XR200 around at one point though, as I recall.

Jeff

Xr250r is lighter than xr400 and has good power low to mid rpm. It is a long stroke motor, in relative terms. Add an inverted fork with billet clamps and the steering is very taught. Turns sharp and precise with shorter wheelbase and tight steering geometry. The xr250 has a six speed transmission with very perfectly spaced gear ratios. Rear suspension has more progressive linkage ratio. Better over roots and rocks (this I s relative to an mx bike).


Jeff

 

[(F5)]

I got off my old KDX200 1991 onto a then new XR400. Went ok but felt like landing a block of flats (apartments to you guys). I stalled it and couldn't start it again. That was a blessing. My rattley old kdx had worse brakes perhaps but I wouldn't have traded back for a bucket of cash to ride that 400 again.

 

[farmerj]

10-4, makes sense. I had a Husaberg FX450, and while great in many ways it is hard to overcome weight issues. It was 15 lbs. heavier than my GG300, but all of it was in the rear. Fine if you only ride smooth flowing singletrack and fire roads - and never have to pick it up! Not so good in the woods!

So your comments help me see where the XR250 would work better.

Jeff