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Connection for Carb Heating Circuit

Posted: Wed Oct 22, 2008 10:14 pm
by markzxr400l3
Guys,

Can you help yet again. I have tried the manual but its not a lot of use.

My bike (L3) has a carb icing circuit fitted but one end is blanked off (M5 bolt in end of coolant tube). Seems odd to me that it connects near the drain point between the bottom of the rad and the pump, comes up through the carb and is then just blanked. Can anyone let me know where this pipe (after the translucent plastic bubble) is meant to connect back into the heating circuit?

I assume It must do that or how else would coolant circulate through the carbs? Nothing will flow the way it is and there is nowhere for the heated coolant to go. The plot thickens as there is also obviously no point to connect it back into or there would be a big puddle of coolant on the floor lol.

As always, all help is appreciated.

Mark

Re: Connection for Carb Heating Circuit

Posted: Wed Oct 22, 2008 11:18 pm
by Scott221
Pipe 1 - comes from the left hand side of the bike. Outlet of the radiator hose has the pipe which branches off and connects to the left hand side of the carbs on the nipple.
Pipe 2- comes from just under the cyclinder head and connects to the centre link pipe on the carbs
Pipe 3 - can't quite remember where thsi comes from but its obvious and connects to the nipple on the right of the carbs.

Re: Connection for Carb Heating Circuit

Posted: Wed Oct 22, 2008 11:26 pm
by RedexRobB
assuming you have the carbs with the plumbing fitted

they plug into these pipes, as shown on the underneath of the carbs next to the float bowls below the outlets. And as scott said, the one with the bubble connect to the carb on the right, and a pipe from the block connects to the carb on the left :smt001

Re: Connection for Carb Heating Circuit

Posted: Wed Oct 22, 2008 11:31 pm
by Scott221
The one from the block connects to the big centre pipe in the carb doesn't it?

Re: Connection for Carb Heating Circuit

Posted: Wed Oct 22, 2008 11:37 pm
by RedexRobB
Just goes to show i dont read doesnt it, scott didnt say what i said at all!

no, thats for the fuel pump pipe mate. So unless ya bike runs on coolant......

Now what have you gone and done while re-assembling lately scott? shocking

Re: Connection for Carb Heating Circuit

Posted: Thu Oct 23, 2008 12:01 am
by Scott221
Yeah thats what I mean. Was just explaining that there are 3 pipes that connect to the carbs. the 2 for the coolant and the one from the fuel pump. My bad.

Re: Connection for Carb Heating Circuit

Posted: Thu Oct 23, 2008 12:51 pm
by markzxr400l3
Scott221 wrote: Pipe 3 - can't quite remember where thsi comes from but its obvious and connects to the nipple on the right of the carbs.
Nearly there guys but its actually ^^^ where pipe 3 comes from that I have a problem with. Rob I have all connections as you describe but on the end of your green bubble pipe it does not connect to the coolant system. Can you advise where pipe 3 goes at the other end from the carbs?

On your pic rob its the other end of the pipe buggering off under cyl no 2.

I forgot to reconnect the centre pipe last time I set the idle mixture screws, scott, the puddle of petrol pumped all over my floor proves that this baby is not coolant LOL.

Re: Connection for Carb Heating Circuit

Posted: Thu Oct 23, 2008 12:52 pm
by Scott221
I'll go and check now...


Ok, this pipe originates from just under pistons 1 & 2. Its on the cylinder head smack bang in the middle of the two. They're are 3 connections on the cylinder head. 2 on the top one on the bottom, the bottom one is where this pipe (pipe 3) originates from.

Re: Connection for Carb Heating Circuit

Posted: Thu Oct 23, 2008 3:22 pm
by RedexRobB
as scott said.

Even i got it wrong just then. some reason i thougth the pipe from just by the genny had the bubble on it!

So.....

Pipe that splits from just by the generator cover plugs in on the left hand side of the carbs, the one with the bubble on it plugs into the right hand side of the carbs. The other end of that plugs into the outlet on the back of the engine block in between cylinders 1 and 2.

You can see the outlet here

Re: Connection for Carb Heating Circuit

Posted: Thu Oct 23, 2008 9:51 pm
by markzxr400l3
Ahh, things become clear.

I have a zx4 head. I have a zxr L3 bottom end and rest of bike. Hence I have plumbing for the carbs but nowhere to plug it in. Makes sense.

No fix for it though. Carb circuit will have to stay blanked off.

Cheers guys.

Mark

Re: Connection for Carb Heating Circuit

Posted: Thu Oct 23, 2008 10:07 pm
by RedexRobB
oh what!

That does explain alot! They are supposed to prevent carb icing so no big deal if you leave em out :smt001

Re: Connection for Carb Heating Circuit

Posted: Fri Oct 31, 2008 11:49 am
by parby81
whilst we're on this subject. What is the black thing in the tubing that goes to the left hand side of the carbs, from the coolant drain bolt side. Halfway up the engine there is a black thingy. Is it a non return valve or something? What is it supposed to do?

This can be seen in the L model cooling section of the manual, page two, in the UK spec square. Just to the right of 'B' hose clip

http://www.zxrworld.co.uk/Manuals/L%20M ... er%203.pdf

Re: Connection for Carb Heating Circuit

Posted: Sat Nov 01, 2008 9:59 am
by RedexRobB
I know the bit you mean, ive no idea. :smt017

Re: Connection for Carb Heating Circuit

Posted: Sat Nov 01, 2008 8:13 pm
by parby81
cheers rob, as helpful as ever :tease

viewtopic.php?f=7&t=7354
Top picture you can see it easily.

Anyone else any ideas?

Re: Connection for Carb Heating Circuit

Posted: Sat Nov 01, 2008 10:54 pm
by RedexRobB
well ive just had a look at the parts book and according to that its a 'valve assembly'. Could simply be a 1 way valve so that coolant goes in direction of the rest of the system?