New member with a not so new KLR 250 (KLR Project)

[crpt]

Hi Ponchov
That's right on the money. The two major techniques to lighten a piston is with holes on the skirt, or by removing material with a lathe/milling machine (also by hand). I prefer the later one. More material can be removed without weaken to much the piston. Besides today's piston have already very thin skirts.
Also the countersink on most every hole you come across, is also very good for 2 things. Better lubrification as you have mentioned, and also to avoid striping of the threads. Should also be done in every oil return hole.
After refacing the cilinder every hole was lightly countersink. By the way just as I said above the cilinder was lowered 0.4mm 
Later i'll post some photos of the cilinder. Yesterday the barrel was painted with high temp coating. And went to the kitchen oven, some 20 minutes. For this part make sure (very sure) your wife unsderstand completely your other passion... 

I got hold of a complete gasket set (Athena), but the lower cilinder gasket is 0.5mm thick. Wich is fine for oem rebuild. But since I wanted to raise compression ratio and already lowered the barrel 0.40. After some serious thinking (2 seconds  )
Gain another 0.25mm in the gasket itself. Had some 0.25mm gasket paper lying around. So made another one with half thickness.   Total lowering will be 0.4+0.25=0.65mm, more on that later. 

[PonchoV]

What ratio (compression) are you going to have?

[crpt]

And most definitely lower the cilinder 0.3~0.5mm. Then match all ports between head and barrel. But still have to weight the piston and measure the combustion chamber.
Compression ratio will be around 11.8 to 11.9. As I'm looking more to the mild than to the wild side of this engine.

By the way this Namura piston weights exactly 221.7 Grams. In it's standard form.

Still haven't measured that combustion chamber. But CR will surely be bellow 12:1 Those initial numbers will be an exact fit
I think haven't mentioned it previously, but this engine must work perfectly with 95RON gas, just as it does now.

[HotShot]

 .   

[crpt]

Just a few more updates. Today the major work as been cleaning, washing, painting. engine side covers, cilinder, valve cover, kick starter and so on.
Anyway here are some pictures. Athena gasket top side 0.50mm, homemade gasket bellow 0.25mm
For DYI'er: gasket paper, scissors, pen (to draft) and 15minutes  

[crpt]

Washing and painting is realy boring. But theres no doubt it apeals to the eyes
Here's one example of before and after  


The piston and cilinder have already been introduced to one another, rings also. First impression without even assemble the remaining engine components. This namura piston and rings seems to be really good. I had already measured the piston, and noticed that it as closer tolerances than OEM. Mostly due to metalurgic advances. In the end it fits much more snugly than the OEM. Same for the rings 0.09mm clearance   very good indeed. More on that later...

TIPS&TRICKS:
This cilinder has already been honed, but today before puting the piston in I wanted to improve a litle more. But at home i have no tools for honing cilinders. So here's my home made (10 minute) tool.
Mounted in the drill:

Taken apart- Nothing more then a small piece off aluminum tubing I had lying around, cut a slot. Take a piece o sandpaper put a staple in the midle. Put sandpaper "butterfly" in the tubing, and of you go.


Cilinder with piston on. Water pump cover and other bits already painted. Gasket in water pump is homemade. Paid almost 70€ for a complete gasket set. Came with two water pump gaskets, but none of them would fit. 

[crpt]

One more update. Yesterday morning was looking at the bike. And considered if the work with the engine was going so well.
Why not refurbish all bike? With that in mind I started like this:

[BakonMoto]

Looking sharp, crpt ! Keep up the good work and keep the pics coming.

B

[crpt]

The funny part is that I only wanted to change valve seals, and cam chain idler 

[crpt]

There are probably tons of tips&tricks for our beloved KLR in the internet.
But here goes a few more that I've been using.  

1 - Rear exausth gasket from Suzuki Burgman 400 >K7 fit right on OEM silencer.
Suzuki Part number is 14771-05H01

2 – Clutch: Old clutch springs (shorter) can have a new lease of life, if
13x17(18)x1.5 washers are used as shims under them. This is also valid to
increase spring tension on new springs.
This washer are usualy found as oil change gasket. Aluminum or copper as a
choice. Prefer the solid ones not the roled copper ones.
Of course, they also work great as oil gaskets on our KLRs.  

3 – Magnetic plugs can be real engine savers. But a strong magnet on the
outside of that oil plug works even better, as all the advantages of a complete
magnetic plug, plus is easer to clean.
Remove the plug from the engine, then simply remove the magnet and all that
crap metal sticked simply fall off.

4 – To remove the stator an impact wrench air or electric, doesn’t matter,
and a simple M20x1.5 bolt works wonders. And the bolt is much cheapper than the
“extractor” sold everywhere.

[PonchoV]

Good stuff

[crpt]

Update: This weekend was dedicated to the engine. Except for the bottom end, most other parts have already been cleaned, washed, painted. So sunday I started with a prety ugly bottom end, something looking like this:




After washing and painting, high temp flat black for the bottom and cillinder.
Head and head cover, bright metalic black.
Than slowly worked my way up:





Theres is still some work to be done. Namely stator, and chains. But progress is evident and the rebuild is looking sharp.
In fact I'm quite pleased with the way it look's. Sorry for this pictures, but my cell cam isn't the best for this task.

Note for future reference: Be very sure your wife really understand why you are cooking engine parts in the kitchen oven    

[MacGyver]

Excellent write up crpt ,thanks for taking the time to share the info 

[BakonMoto]

Dude! Your engine is full of chain!!!  I'll bet it was noisy.

But seriously, you're going at this the right way and it oughta be a bike you'll be proud of when finished. Of course, then it's time to get out there and get it dirty again .

Bryan

[crpt]

Later on I'll try to post a few more pictures. The engine is ready, well almost there are some detailing to do.
Those letters in the engine head must be painted. And to say the truth haven't had much time left.

Next will be the carburetor. Wash and paint the front suspension, wich as already been refurbished.

Then and only then. I'll start to put the bike together.
Until now every nut and bolt found it's way back thankfully. 

[Sandring]

Very cool project,  I am the same way.  I like to buy things that need work done to them.

Good luck

Chris

[crpt]

Another weekend and some work on the bike, not much tough.  
That engine found it's way back to the frame. Front suspension is ready, rear suspension is ready also. Foot pegs and kick starter went in smoothly. Nothing more as been done. Litle time and to many things to do.
But in fact this few things took a lot of work.
- Cleaned and painted/varnished front suspension and triple tees, put new fork gaiters (same crappy quality  ). Need to find better ones.
- Same at the rear cleaned/painted rear end components. New grease, same seals and rollers, wich in fact are in very good condition. Don't have photo (yet) off rear shock in place. But it's already done. Even the shock and spring was cleaned/painted.
Engine fitted without any complains. Still have to "lock" those bolts. Every lettering on the engine was revived. With some detailing work. Looking back I should have varnished that head cover...    
Now more images  

[crpt]

[SSMSCHULZ]

    Looking good.  Keep up the good work.

[crpt]

Another weekend and a few more work done. Now it's starting to look like a bike  
Major work was done in the cleaning department. It's hard to believe how much "crap" might acumulate over the years  
Front and rear suspension complete. Head light in place. Front blinkers coneted but still all the electrics remain in the line for some work.
New ball bearings on both wheels. Chain, sprockets, etc. already in place. Wash/clean/lube the chain is a simple but very boring work. But finaly it's done. Still need to put some air in that front tire wich was emptyed to paint the front rim.
Yesterday was dedicated almost completely to the front wheel. That odyssey started when I bought the bike.
OEM front wheel (Takasago-aluminum) had a bump. So another rim had to take place. Beeing quite pricey I went trough the cheap road. What I come up with was the mosty crapy chinese steel rim I could find. I know, I regret it almost everyday.   that wheel "was" chromed   but in the last two months almost all chrome simply fell off  . Off course I knew it was cheap (very). Usually don't trust in that kind of materials, but... at the time my wallet agreed.
So bought it, bring it home, then some four hours later.
Had a "new" wheel completely relaced, new spokes, new bearings, and new tires (Michelin Anakee II), balanced the tire and the world seemed to smile but in a matter of days the chrome fell off. So yesterday started with a very rusty wheel rim.
Much washing/sanding/zinc/aluminum paint, then bright black metal paint. Later that day had a "new" rim wich looks like this...


I like that BLACK look, maybe latter on the rear rim will have a simillar treatment  






Meanwhile the carb was also completely cleaned again. Had done that a couple months ago. So didn't take much sweat  
The spring was tied (4 Loops), and the needle found a shim (0.6 mm) in the way back to it's place. Still looking for 125 jet to upgrade from the oem 122 wich is still there. The 35 main jet probably won't be touched. Some threads ago i said this bike still need to give good gas milleage, and that is a keeper.  

Radiators left and right are also in place but not conected yet. Also washed and painted with flat black high temp paint.
Rider foots pegs, brake pedal, gear pedal and kick starter also went back to the bike. Kick pedal in flat black paint. All others in bright metal black with a few layers of laquer.      

Just a few more   

[TrailRider]

Meanwhile the carb was also completely cleaned again. Had done that a couple months ago. So didn't take much sweat 
The spring was tied (4 Loops), and the needle found a shim (0.6 mm) in the way back to it's place. Still looking for 125 jet to upgrade from the oem 122 wich is still there. The 35 main jet probably won't be touched. Some threads ago i said this bike still need to give good gas milleage, and that is a keeper. 

Betraying my ignorance, please explain, " The spring was tied (4 Loops) . . . "  If you're talking pre-compressing spring coils, looks like initial slide lift would be easer; later slide lift harder (although spring mechanics confuse me!).

Do you have "main" and "pilot" jet nomenclature reversed?  Manual mentions pilot as, "35," mains from "118" to "122."

Regardless, astounding and outstanding rehabilitation; way to go!

[crpt]

  Yep! That's the problem of trying to explain something in a foreign language... The idea was right, the write up wasn't. They are reversed.
Pilot 35, and main jet 122. Thank's 

Some people cut the spring I prefer to just tie it up. Than if I want to go back, just untie it and everything remains the same 
Anyhow this just make the spring shorter, so there is less initial pre-compression.

[TrailRider]

Anyhow this just make the spring shorter, so there is less initial pre-compression.

Again, springs confuse me, but . . . seems like the spring rate would be altered from pre-compressing a segment. 

Heard of clipping slide spring coils; affects initial offset (easier to raise), but . . . I think the shortened spring is stiffer than the original long one . . . hey, I already SAID springs confuse me!   

[crpt]

Holly cow you are really messing your springs   But just as you said it's easier to raise.
More responsive to the right hand movements. That's what really matters. Forget the spring  



Well it's far from over the paint saga still goes on. So here is an image to explain how boring this part is.
On the top side cover washed with some "mastique" "putty" (fill in the right word please) but not painted.
On the bottom already painted with 2 coats of "pure" white, in other words refrigerator white  



Still missing more coats of white paint and 2 or 3 coats of varnish. By the way somebody, somewhere, asked what I was using for this job.
Let me say this my backyard seems like a ratle can festival...

[crpt]

Well here goes a few more pictures. I know you guys want to look some good bikes... Here it is  

This time was the sub-frame. Sanded, washed, painted with a few problems in between, but this is the final result.
Side covers and remaining plastics are still drying, but decided to take a picture just to learn how it will look in the end  
Till now I'm quite happy with the results, and seriously considering take an action on that rear wheel and paint it black.
Like the front one  

Started like this:


Ended like this:




Not sure if I mentioned it earlyer, that transmission is a 16x42. Veryyyyy long relation especialy useful for road only use.


Meanwhile just to understand the diference in the look of those plastic parts, here's another one. Head light cover, and side covers already painted.
Rear tail as it was in the begining.   Quite ugly...
By the way, this parts are resting on top of my last year project. Wich was a small dinghy. 


Among those things the exausth pipe was washed, painted and the carbon removed. Then found it's way back to the engine.
A lot of carbon came out of that small pipe   at least five aplications of hoven cleaner and hot water.