CB250N - Yes another CB

[Screamin TE]

I definitely have a swing arm there. I'm happy with a straight swap mate. I'll be back on Friday so I can dig it out then and we can go from there if you want?

[Vosy]

I definitely have a swing arm there. I'm happy with a straight swap mate. I'll be back on Friday so I can dig it out then and we can go from there if you want?

Sounds good mate, appreciate your help

[Vosy]

A big thanks to Screamin TE for the swing arm, it is all painted now and I should get it re assembled today.

I'm starting on the carbs today to, if anyone knows what the idle screws should be set at could they post it up? As I would like to have a solid starting point and tune from there

Pics to come soon.

[Vosy]

Something I did while waiting for paint to dry. My throttle cable was completely seized, and I saw this trick on someones thread here.

Filled a little bag with lube which I cable tied to the top of the cable.


Next morning I checked on it and the lube had ran all the way through, and the cable was free and easy

[Vosy]

And this is how the bike is standing at the moment.


I finally put the stainless steel allen bolts on to replace the existing casing bolts. Finally feel like Ive made some real progress.

[kale]

That is looking fantastic mate, though you're making me look like a mug.

[Vosy]

How is yours going mate? Manage to put any hours into it?

[kale]

Zilch, still sitting bare framed with me looking at it longingly every time I raid the back fridge for a beer. Waiting to see yours finished so I can copy it all in one hit haha.

[g0zer]

I'm starting on the carbs today to, if anyone knows what the idle screws should be set at could they post it up? .

If its a twin, its no so important so long as they are both set the same. i use a small split pin straightened out as a feeler guage, cos its round on one side and flat on the other and set a gap slide to venturi of about half a mm to a mm before fitting the carbs. High enough to get it to start and idle. Then mark the idle screws with a paint pen or something.

When it comes to starting and adjusting idle, just make sure you adjust screws the same amount for both cylinders. The closer you can get the idle by gapping the better.

Idle mixture screw just set to middle of adjustment range. If it deviates much from this you need to change the pilots anyway.

[Vosy]

Zilch, still sitting bare framed with me looking at it longingly every time I raid the back fridge for a beer. Waiting to see yours finished so I can copy it all in one hit haha.

Haha, you know what they say about imitation being flattery.

[Vosy]

If its a twin, its no so important so long as they are both set the same. i use a small split pin straightened out as a feeler guage, cos its round on one side and flat on the other and set a gap slide to venturi of about half a mm to a mm before fitting the carbs. High enough to get it to start and idle. Then mark the idle screws with a paint pen or something.

When it comes to starting and adjusting idle, just make sure you adjust screws the same amount for both cylinders. The closer you can get the idle by gapping the better.

Idle mixture screw just set to middle of adjustment range. If it deviates much from this you need to change the pilots anyway.

I'm not sure I fully understand what you mean about setting the gap?

[g0zer]

the gap that lets just enough air through to idle the motor

[Vosy]

You use a pin as a feeler rather then measuring the amount of turns on the screw? makes sense I'll do that tomorrow

[Screamin TE]

Vosy, I've got a repair manual for these at home. I'll have a look when I get back and post the idle screw settings and main and pilot jet sizes. Once it's started and running you'll need to get it balanced. I got mine checked at rockingham Honda for $50.

[Screamin TE]

OK, Ive got the repair manual right here and it says for the 250, the air screws are 2 turns out. So screw them down till they touch and back them out 2 full turns. There should be a spring and an oring beneath them as well so check that. The idle is adjusted with the plastic knob in between the two carbs.

Float height should be 15.5mm and from memory the jets are 105 and 52. You dont really need to set the needle height as it sits at the bottom of the piston and the piston will seat at the bottom of the carb throat anyway.

Make sure the pistons arent scored or damaged and slide freely in the bores. Check the springs are of equal tension and length and check the needles for excessive wear. You can get the float bowls and piston caps off with the carbs fitted to the bike. Ive done a few jet and needle changes this way.

If you want a jet and needle kit, keyster japan do a ripping kit with o-rings and gaskets for around 35 per carby.

Let me know if you want any other info mate.

[Screamin TE]

OK, Ive got the repair manual right here and it says for the 250, the air screws are 2 turns out. So screw them down till they touch and back them out 2 full turns. There should be a spring and an oring beneath them as well so check that. The idle is adjusted with the plastic knob in between the two carbs.

Float height should be 15.5mm and from memory the jets are 105 and 52. You dont really need to set the needle height as it sits at the bottom of the piston and the piston will seat at the bottom of the carb throat anyway.

Make sure the pistons arent scored or damaged and slide freely in the bores. Check the springs are of equal tension and length and check the needles for excessive wear. You can get the float bowls and piston caps off with the carbs fitted to the bike. Ive done a few jet and needle changes this way.

If you want a jet and needle kit, keyster japan do a ripping kit with o-rings and gaskets for around 35 per carby.

Let me know if you want any other info mate.

[Vosy]

OK, Ive got the repair manual right here and it says for the 250, the air screws are 2 turns out. So screw them down till they touch and back them out 2 full turns. There should be a spring and an oring beneath them as well so check that. The idle is adjusted with the plastic knob in between the two carbs.

Float height should be 15.5mm and from memory the jets are 105 and 52. You dont really need to set the needle height as it sits at the bottom of the piston and the piston will seat at the bottom of the carb throat anyway.

Make sure the pistons arent scored or damaged and slide freely in the bores. Check the springs are of equal tension and length and check the needles for excessive wear. You can get the float bowls and piston caps off with the carbs fitted to the bike. Ive done a few jet and needle changes this way.

If you want a jet and needle kit, keyster japan do a ripping kit with o-rings and gaskets for around 35 per carby.

Let me know if you want any other info mate.

Cheers for that mate, Ive just ready over your post and that is everything I checked anyway, so its good to know I did an OK job. Float height is one thing I didnt check, so will have to re-visit that.

Cheers for your help mate, Ill keep that carby kit in mind incase I need it.

[Vosy]

Carbies cleaned and mounted (might soda blast them later) and rubber inlets have been soaked in rejuvinating spray.

Test fitted the air filter and bracket I made, pretty happy with them So apart from oiling it I think I will leave it how it sits at the moment.

[Vosy]

Cleaning bits and pieces getting ready for the exhaust. There seems to be a constant reminder of how bad this bike was neglected before I got it.

obligatory before and after pic.

[Vosy]

Ok, so the exhaust.

At about the same time I bought the bike, I bought a pipe bender from supercheap. Seemed like a good idea at the time.

Now there are a couple of tricks to this, but I still couldnt get it.

Fill the pipe full of sand.



Seal the ends.



Apply heat while bending (Yep, just a heat gun straight on it. Its all I have, If I had an oxy im sure it would of worked fine)



And.. Fail #1.



Second attempt, a little bit slower and a little bit longer with the heat.



And thats where I gave up and went to the local exhaust shop. He ordered me the bends I needed.



So for the next coupel weeks I will be slowly putting the exhaust together. Will update when I make some real progress.