CB250n Brat/Tracker our first build

[Windsorlad]

So the only thing we managed to do with the bike this week was move it from the shed, through the house into the garage.
However it has all been happening today, the log book arived, so my son insured it and took it down for the MOT. It passed with flying colours but is still running a bit rough.
I have made a carb sync guage and an adjusting tool so aim to put the new header seals and exhaust wrap on and then try and get her running smoother. More photos to folow at the weekend ;D

 

[crazypj]

It's always going to run a bit rough without stock airbox, I'm sure you'll learn to live with it though (or end up getting some Mikuni's )

 

[Windsorlad]

I figured that would be the case but assume I can make it acceptable with a bit of a tweak. She has a misfire when I let the throttle off and needs the chock on for about 5 mins. At the moment I am just happy she runs. If I went with Mikuni's, what model and jetting would you suggest?

 

[Windsorlad]

Yesterday we checked the cam chain tension, valves and balanced the carbs (I think) with my home made gauge.
I found this just about the most tricky job we have done.
We also wrapped the down pipes, I soaked the wrap as suggested and am pretty pleased with the result.
Lots of smoke as they dried out but nice and tight.
Still got to replace the stock gauges but will probably put a couple of miles on them first.

 

[crazypj]

If you get Mikuni's, don't go bigger than 30mm for slide (VM) or 34mm for CV
Probably the same one's for a Triumph 500 or 650?
They will probably be set up better than the ones we get in USA

 

[Windsorlad]

If you get Mikuni's, don't go bigger than 30mm for slide (VM) or 34mm for CV
Probably the same one's for a Triumph 500 or 650?
They will probably be set up better than the ones we get in USA

Thanks for the info crazypj, I will be keeping my ey out for a set.

 

[Windsorlad]

Made a couple of tank decals from carbon fibre effect vinyl and got round to fitting them today. Just need to decide on the dials and the little CB is finished.

 

[crazypj]

Weather is looking pretty good over there for this time of year?

 

[Windsorlad]

Its been pretty wet and windy, some localised flooding but now sunshine and frost. Winter is running late in UK.

 

[crazypj]

That sounds more normal.
'Winter' was normally worse at end of Jan into Feb when I lived there (March wasn't too fantastic either)
BTW, looking good, I like the way tank 'lines up' with the underside blacked out 8)

 

[Windsorlad]

I think our winters are getting later and shorter, I commute all year round on my CBF so hoping for a real short one.
Thanks crazypj I think the tank works well and now thinking of a black seat to continue the line.

 

[mattbarber660]

Really enjoyed reading your project! Me and a friend have just picked up two of these as our first projects. Did you have any luck with the carbs? Everything I read says that the pod filters aren't great but the airbox is just not an option if you want to strip it right back!

 

[Windsorlad]

Hi Mattbarber, I am glad you asked the question as the bike has been running like shit and you nudged me into doing something about it.
Up until now I have been running the bike with 1/4 choke as it just dies without it. Uneven running and needing to keep it revving over 2k.
So today I took the carbs out with the idea to check and clean. I found the spring that operates the second carbs choke butterfly was not connected. Also a fair bit of crap in the carbs.
Next I polished the slides and used a couple of O rings to space the needles up.
Put her back together and am ecstatic, she fired up on the button, only needed minimal choke, once warmed up had even tick over at about 1100 rev's, throttle is smooth.
She is purring like a kitten and although I have to admit more luck than judgment, I am soooooooooo happy I ditched the air box.

 

[mattbarber660]

That's great! Good news. Can't wait to get these babies up and running.

 

[MotoCrazy]

This bike is awesome! i just picked up a cm200t for my wife last week and i believe this is exactly what we are going for..and she loves the MAG wheels..now i just need to find me some of those!