Cold start problem

[iainw]

When I got the bike back together I put bigger jets in to compensate for the new pipes and tuning. It sarted from cold 2nd kick, ticked over quite well so I spent the rest of the day plug chopping and jetting. Since then it won't start from cold, it needs a bump with the down hill momentum to keep it going.

It fires, runs for a second or two then dies. I think it's a choke problem. When it's running and warm all is OK, it starts first kick. I put the jetting back to what it was when it started OK but the issue is still there.

How does the choke actually work? I know it makes the mixture rich but how, is it so simple it can't fail to work and I should be looking elsewhere? Any ideas? It's a 4L0.

[cb250g5]

Have you put the float bowls on the correct carbs?

Only the lh one has a choke jet in it, so wrong way round, means no choke.

[arrow]

Check you have the short rubber pipe fitted between the two carbs.

[iainw]

Apr 7, 2012 17:39:40 GMT 1 arrow said:

Check you have the short rubber pipe fitted between the two carbs.

The pipe is connected but it was becoming a bit of a sloppy fit, I replaced it with a new piece but still no change. Thanks Arrow.

Apr 7, 2012 12:33:39 GMT 1 cb250g5 said:

Have you put the float bowls on the correct carbs?

cb250g5, you were bang on the money, it started first kick this morning! ;D

[Deleted]

whats the difference between the 2 bowls? what do you look for, thanks

[iainw]

Apr 8, 2012 23:41:34 GMT 1 @ken007 said:

whats the difference between the 2 bowls? what do you look for, thanks

They both have the brass overflow pipe sticking up but the lhs one has a bit extra casting at the front of the bowl to cater for the choke jet. If you look at them both together it's obvious, though I didn't notice it until cb250g5 said they were different. Have a look at butchers pics here, they're from the lhs carb
rdlccrazy.proboards.com/index.cgi?board=mods&action=display&thread=14900 the gasket runs round the choke jet at the bottom, the correct bowl will match it.

[Deleted]

thanks iainw, is this what you mean , i pulled both the bowls off and the only difference i could see was on the left hand bowl in the picture it had the extra hole behind the big hole, and the right one doesnt

[iainw]

They look like two lh bowls to me. My rh bowl doesn't have the big hole casting. Maybe someone who's seen this inside of more carbs than me can confirm it.

[Deleted]

gday iainw, the one on the left has the hole and the one on the right has the same casting but isnt drilled out, im assuming the left 1 is the left bowl and the other is the other

[oldelsieboy]

CHOKE BOWL


NO CHOKE


OEB

[Deleted]

thanks alot oeb, , i got to hand it to you, you have helped me out a few times, have some karma, ken

[iainw]

Interesting. The bowls on mine are completely different, the large hole casting is not there on my rhs bowl, nothing as subtle as thos shown.

OEB, what's the top red ring indicating?

[oldelsieboy]

Apr 9, 2012 16:37:10 GMT 1 iainw said:

OEB, what's the top red ring indicating?

There is a number 2 cast into the bowl similar to the numer 1 that can be seen on the NO CHOKE bowl.

OEB

[iainw]

I don't intend on taking the carbs off for some time now as every thing is tickety boo, but next time I'll have a good look at the bowls for markings and take a pick or two.
Thanks all for the help and education.