Bandit250. Publish a drawing of the sleeve.

As a result of measuring the cylinder inner diameter of the bandit 250, it was 0.02mm ~ 0.03mm wear. Bowling is required.
However, oversize piston was discontinued. One over and two in over both.
With oversize piston it can increase a little Displacement. It is a small happiness, but the dream was also collapsed ephemeral.

I examined the diversion from other bikes of the same size, but it was impossible. Bandit bore largest.
The road that was left to me to make a sleeve.
I decided to remove the sleeve reluctantly.
Hmmmm. Even though labor just boring.

It I remove manually hydraulic press.
I've made a scratch on the block side when removing it. This may be shaved in the rotary tool.

This is a removed　sleeve.

The top side of this there is a recess of the intake valve.

First, we measured the dimensions Remove the only one cylinder of this. And I drew a drawing. In this way ↓.

f you are riding in bandit 250, moreover, allowing you to use this drawing if the engine had a malfunction.
Fitting tolerance of outer diameter has become a m7 but will that's m7 φ55.011 ~ φ55.041.
This dimension, measured was φ55.100. This is too tight. So we have changed without permission.

Other notes,
There is no valve recesses -
- An inner diameter of 1mm small (after press-fitted into the cylinder block, to finish in φ49.00 by bowling.)
Top surface is higher than the block. Milling required.

(Even if there is a problem I do not take the responsibility.)

As usual, the material arrange DENSE BAR. I bought a 60φ. So near the top will remain casting surface.

It was lying on the edge of the factory, and I can use this residual material.

The next is the penance. I must billet by hand four sleeve.

I went to Modeler Kikawa's house.

I went to Kikawa's house. He is a senior university.
He is a company employee. However, he is also a modeler.
The modeler is the people who make very realistic plastic model. Work that he make is amazing.

Kikawa's says. "I am a digital modeler."

To explain the digital modeler, it is such a thing ↓

Previously, when the modeler who has wanted to detail up, they were shaved by hand.
However, Kikawa is shaved using a desktop NC milling machine.

Digital modeler has a modeling and the coloring of the technology. But not only that, 3D modeling technology and NC machine technology also has.
It is because creating a digital data, are referred to as "digital modeler".

These are works made by Kikawa. ↓
It is Amazing. I do not think this model. Quality is high.

This great work has been created from this hairy hand. Here once entered mosquitoes would not be out.

In recent years, why digital modeler had emerged?
The reason is twofold.
Free CAD, CAM was released.
Desktop NC milling was released.

Machine Kikawa's is using is the Kit Mill of "original mind".
Video is here. ↓

Control screen of the PC side is this photo.
It has been attached to the ability to display the tool path for this software.

Kikawa do not have so much time because the company employee. It is the fullest so make the work.
Editing and management will do what our company(Araki F Machine).

I have proposed to Kikawa. Do not try to report the work of digital modeler. In this blog and YouTube channel.

His answer was generally OK. I decided to do it.

Engine of Bandit 250 What is the cause of the sound rattle-rattle?

I checked a cylinder head,
However, it did not have the abnormality.
I exposed all the parts from the upper-waist of the engine.

Forgive.Please forgive me; Bandit

The oil of this seemed to be changed frequently.
A piston does not have the terrible damage.

This motorcycle is run around 25,000 kilos.
It that I think is suitable for the mileage.

The lower photograph is a state of the heads.
When I bought it, the rubber packing in the cab deteriorated.
It absorbed gasoline from the different course.
The mixed gases of this were very rich and were ill-conditioned.
However, the sedimentation of its carbon is not terrible.
I ran for a while after I overhauled a cab. It might be removed by the result.

One of the cylinder has little carbon and burns..
If it is the motorcycle of the cab, it is not strange.
There was not the sedimentation of the carbon in the exhaust port. A normal state.
This motorcycle ran the long mileage on rich gas.
When the valve seat that I think sandwiches the carbon. I intend to do grinding.

The lower photograph is a state of the cylinder inside-surface.
I think that there is much brightness.
Its state is not bad.

I thought about the cause of the abnormal noise.

I took one piston off the engine among them for trial. I put it in a cylinder. It had a gap of 0.5mm. I was able to make a sound rattle-rattle.

I measured the cylinder using a cylinder boa gauge. As for it, 0.02mm - 0.03mm diameter got wide. It was worn gently. The human being cannot confirm it by the naked eye.

I see the gap of the piston ring from the top.

I understand that this engine sucks in oil.

The cause is either abrasion of the cylinder or abrasion of the cylinder + piston.

I ordered a new piston, and I compared it. This piston was not worn that much.

I removed a cylinder sleeve from a block. Outer diameter was φ 55.10mm for some reason.
I think normal press-fitting margin is about φ55.03mm- 55.06.
Possibly it may be such a thing.
This has too big Press-fitting margin.
Residual stress is let loose by a secular variation.
The inside diameter becomes slightly big.

Cylinders are not usually worn so a lot.
It does not decrease by 100,000 kilos even if I measure the cylinder of the car which ran. The con rod metal is the same, too.
During a run, the engine inside gets wet with abundant oil. The parts float to the oil slick.
It virtually gets a slimy eel by hand.
In the case of this engine, quantity of abrasion on the piston side is usual.
This engine ran with rich gas for a long time.
This was exposed to combustion gases with much HC (hydrocarbon).
The cast iron sleeve is weak chemically. It had priority over a piston and would be worn.
I have seen very worn sleeve of SR400.
Possibly that might run a long mileage by rich gas, too.

At first where will the performance of the engine having good mixed gases deteriorate from?
I think ,valve face and valve seat .
Valves are always high temperature and dry while driving.
The lubricant has only the carbon which is a by-product of the combustion.
During a run, the valve turns little by little. seat & face sharpen each other.
However, when big carbon comes, there becomes dented, and sealing up worsens.

Therefore I want to do the grinding of the valve.

Make a Bimota SB6 Replica from Suzuki GAG.top clamp making part3 Crest of "b"

The thing which I ordered arrived. It is a ball end mill of 1.5 φ.

I engraved a crest of "b".

We've published our face book page.

We've published our face book page.
here↓
https://www.facebook.com/arakifmachine.en

Bandit250. Very noisy engine.

I did fuel level adjustment for this carburetor. Though the engine became in good condition.
But a sound is loud rattle-rattle.Exhaust gas is stinking.

I hated dismantling this engine very. Because it is troublesome.
However, I took off a head cover to check it. I needed some determination for it.

I checked it. Suspicious partial ... cam chain, valve clearance ... problem were not found.
I expected these. A chain lengthens too much. A valve locks it by carbon.

The head inside is very clean. There is not an oil gossan. I was surprised a little.

The possibility moved to a cylinder and a piston.
It is what I was afraid of most.
I must remove a cylinder block.

Make a Bimota SB6 Replica from Suzuki GAG.top clamp making part2

I am that it which received a request from my customer wants a bimota SB6 style to do a custom in GAG.

Its back side is completed.
I sharpen a top side.

I cut an extra part with a band saw.

I set it in jig and cut it.

It was completed other than a logo of "b"!

By the next work putting a cutline in. The cutline is intended to clamp a fork.

By the way, a top clamp of SB6 genuine is this. (the image borrows it from WEB)

Similar. It is Similar.