A new (long) build begin...from France

[ericz]

Hello guys,

I've just create this topic to exchange about my first 250r build. It will be more a reconstruction than a restoration, everything need to be rebuild.
Frame is 88. Naturraly I thought motor was a 88 (number plate is removed, so??), but I think it's a 86, not sure... need your helps to identify

The objective is to build a bike for a mix between MX and endurance racing. So I will have a lot of work.

I run the bike during 10-15min only... it pull on bottom-middle but can't rev to top, I will understand better why, after the disassembling ^^


Disassembly step

The dissasembly is easy and fast. I have a 400ex and a 450er, many things are similar.
I know the frame is not really "fresh", but after removing everything from it, I just constat that frame is good for garbage..... so many welds I can't count, bend in the front...

Ok...so.. next, we will check the moto now... and a new disillusion.... center cases were cracked on the rear... just behind the swingarm 
The sleeve on top end in cracked too...
Clutch basket need to be change
Transmission and crank looks correct

It's a perfect start for the rebuilt 

After this first disappointed contact, I know this is one of the worst purchase I have made...   
I am not discouraged, it will just take me more time to rebuild (and also a little more Euros )

But I don't know where to start....frame...motor....So I start to contact some guys for the frame, if it's possible to repaired or not... the same for the cases....

So I start to clean all recoverable parts during my evenings, polish some ...etc.. not the biggest steps, but it takes time too

[ericz]

86 Frame
For the problem of the frame, I managed to find a 86 frame. It look really nice with all of the original fixation... one crack on the top on the suspension mount... and under the frame where it is reinforce (in the front)...dirt was certainly accumulated here and had start to rust on the tube of frame, so I have some holes...
Umh...
OK I'll take it... It will be certainly more easily to repair than my 88... A good deal (I think at the beginning) for 300$ frame + rear maier fender in yellow (with no crack)


But...  ... At home, I start to mount a-arms to see if everything is ok.... I notice that one of the ball joints (of bottom a-arms) is a little more forward than the other (for top it looks ok)... around 1,5cm (0,59 inches) with stock a-arms......

     So this frame looks slightly bent too to the right on the bottom front

If it's possible I will try to used this frame after rebuilt it...I will see

[ericz]

Case center repaired

I've found a guy for cases centers repair... Somes pics before/after

[ericz]

Parts identification

This is some pics of my top end... Need some helps to identify parts...

It look like a 86 cylinder, right?

My cranck is a hortods with "CK109" inscription. After somes research on google, it's certainly a long rod.

On the piston I have just "50" and "50x50" on top and "ART" inside... It measure 71mm.... So it's outside the 87-89 piston possibilty...

And I have no plate under the cylinder...

So I'm a little pertubated by this combo...

Have you some ideas?

And for the transmission, what is the tips to know the years?

[ericz]

Somes questions

Concerning the motor....I'm focus on bottom end now. I will replace all bearings and seals by OEM Honda.

Because I want to start with everything new, I will replace the crankshaft too (After I will rebuild the oldest to have one in advance).

1 - is it better to put a short or long rod? Did we feel difference on the motor?  If I have undestrand correctly the different combinaison... With a long rod, we can run with 87-89 piston style or with 86 piston + spacer plate ?
So it look preferable to go with long rod to have multiple combinaison, no?

2 - Have you some recommandation for the clutch basket? And for plate/disc : OEM (with Neils mod) or aftermarket ?


For the top end, I will certainly go bak to a stock bore... New sleeve on my actual cylinder or find a good used top end... Maybe in a second step, I will look for a big bore... But in a first step, I prefer to kept money for racing parts for the frame

[croat1]

Great write up with very good questions.

For starters I’d suggest a basket from Wiseco.

As far as a cylinder I’d look for a another stock cylinder with bores left.

Joe

[croat1]

85/86 cylinders did not have an intake bridge.  Like yours.

Joe

[Jerry Hall]

 

85/86 cylinders did not have an exhaust bridge.  Like yours.

Joe

I never saw a OE cylinder 85, 86, 87, 88, or 89 that did not have an exhaust bridge.  The OE intake ports on the 1985 and 1986 did not have any bridges but the 87, 88, and 89 had two bridges in the intake port

[croat1]

85/86 cylinders did not have an exhaust bridge.  Like yours.

Joe

I never saw a OE cylinder 85, 86, 87, 88, or 89 that did not have an exhaust bridge.  The OE intake ports on the 1985 and 1986 did not have any bridges but the 87, 88, and 89 had two bridges in the intake port

Jerry, yes you are correct.  I should’ve had my coffee before posting. 😬

Joe

[ericz]

Ok thanks, so it confirm that's a 85/86 cylinder style.

I will see after what option I will take for the top end.

Now I have enough to do with bottom end... I have to pass orders for all bearing, seals and gasket (OEM Honda), a new basket and certainly OEM clutch disc/plate

It will be enough for my bank account for this month 

[ericz]

I took advantage of the Black Friday sales to order somes parts : Hotrods crank, DRW case caver, specBolt full rebuilt kit and a seat latch at BVC... Now just to wait for the shipping

Need some advices concerning my frame....

i join 3 pics...  What did you thinks? is it possible to straighten this frame?

I don't kwon of it will have a big effect in the handling... if maybe I can compens with a-arms like ASR or fullflight with adjustable ball joint ?

Find a perfect frame is almost impossible mission in France.... An expedition directly from US will cost a lot.

[croat1]

What was wrong with the 88 frame?  Can you post pictures of the issues.

If you can take the 86 frame to an automotive frame shop and see what they can do for you.

Joe