Bike carbs issue..

[Super-Nova]

Hey guys, ive got some bike carbs for my 1400 nova. Just got a couple of questions, first of all ive bought an external fuel pump that runs at 3-4psi is that ok to run the carbs? Im pretty sure it is, just double checking. Im asking this because ive tried starting it with the carbs on, and the fuel keeps spiting out the air intake for the carbs? just wondering what this could be? Timing? carb balancing?

[MK999]

Check your ignition timing, sounds like it's trying to fire through the inlet. I'd advise someone with a fire extinguisher on hand too as they like trying to set themselves alight when they do that near a bulkhead lol

[Royston]

3-4psi is fairly normal, but are bike carbs gravity fed though? I don't know, just posting the question

[phunkynova]

3 psi is the max for bike carbs best pump to use is a motorbike one for carbs they have a automatic cut off
Mine run well at 2.5 psi

[Super-Nova]

haha yeah i better check the timing! Yeah bike carbs are gravity fed but thats because the tanks usually above the carbs i think! hmmmmm i might have to get another pump then, bit gutting considering i spent £45 on this one...

[Royston]

Just get a regulator to meter the pressure down.;)

[swedge]

I use a facet cube pump and a filterking regulator at 3psi

[nova ian]

Just a thought, you probably haven't but I have heard of people doing it...

Your fuel line should be connected to the single pipe underneath between 2 and 3, if its connected to the pipe at one side on the top the fuel will just p*ss out the otherside!

here's a pic to clear up what I'm on about!

http://img.photobucket.com/albums/v314/cruisindude/20072007243.jpg

[Super-Nova]

guys thanks for the help! im doing this on my phone right now, and i did reply earlier but i think i did it wrong! sorry if you get 2 messages! anyway, thanks Ian! i think i did connect it the ?roe ng way round! i connecTed mine to the top! only thing is, my carbs look slightly different to yours! on the bottom of carb 1 and 2 i have a pipe coming out, and the same with 3 & 4 then they connct with a T Piece in the middle? so basically just wondering is it a rule of thumb that fuel in goes to thbottom

[nova ian]

Not 100% whether all the bike carbs are fuelled from underneath but I know the R1 carbs are and a few other sets I've seen. There is usually only one pipe for the fuel line in though on carbs. Bike throttle bodies obviously would be different as they'd have a fuel rail to the injectors.

In regards to the T pieces you refer too, if they are plastic then I'd say that's not for the fuel line. If you can put a pic of your carbs up it may help. I'm no expert but hopefully this info helps.

Cheers
Ian

[swedge]

I have a couple plastic t pieces on my r1's they are breathers or sometheing definitely not fuel

Beale all bike carbs I've seen have been with the fuel inlet like the one in the pic

[Super-Nova]

ok cheers guys, i'll try and get a pic of my carbs later tonight!

[Super-Nova]

hi guys sorry its been a couple of days, been working non stop. But heres a pic of the carbs ive got...
http://i1054.photobucket.com/albums/s481/Super-Novaa/DSC00253.jpg

http://i1054.photobucket.com/albums/s481/Super-Novaa/DSC00256.jpg

[*Jurgen*]

You have a picture of the underside of the carbs? Easier to tell what's your fuel inlet then.

[nova ian]

You have a picture of the underside of the carbs? Easier to tell what's your fuel inlet then.

Yea sorry mate, a pic of the underside would be better as Jurgen said.

[Super-Nova]

sorry about that guys! heres some pics from the bottom and of the top...and of the nova! This is my first ever project and shes slowly getting there! also the T-piece at the bottom has broken, i am aware of that incase you thought i was THAT stupid not to notice haha
http://i1054.photobucket.com/albums/s481/Super-Novaa/20120508_144943.jpg
http://i1054.photobucket.com/albums/s481/Super-Novaa/20120508_145000.jpg
http://i1054.photobucket.com/albums/s481/Super-Novaa/20120508_145014.jpg
and from the top
http://i1054.photobucket.com/albums/s481/Super-Novaa/20120508_145051.jpg

http://i1054.photobucket.com/albums/s481/Super-Novaa/20120414_121551.jpg

[jeremy fisher]

Do you know what bike the are off? look kinda like CBR1100 carbs, 42mm if they are. Not that that helps!
I tried to trace the path the fuel takes on mine to make sure I got the fuel in the right place. If you take the float bowls off and locate the needle valve then you can normally see where the fuel should be going in if you get what I mean. Mine have sort of T pieces to distribute the fuel to each of the carbs.
I use a bike pump, think most bikes do run pumps. Ideally the one to match your carbs should be used but I think all carbed bikes use pumps (or at least performance bikes) that shut off once the required pressure is reached. Think I got my pump for about £20 of the bay. Just search 'fuel pump' in motorbike parts and make sure its for a carbed bike, should be loads on there.

Good luck! worth it just for the sound!!

[jeremy fisher]

I think the pipes you can see in the last pic of the carbs are just breathers, the ones underneath look like the fuel inlet. Where did you have the fuel connected to?

[swedge]

Bike carbs sound the dogs danglies :)

[swedge]

The t piee you see in the second pic will be the fuel in

Remember there is no return

[jeremy fisher]

/\ I agree

[Super-Nova]

Thanks a lot guys! Youve been a massive help! I was putting the fuel in the wrong way! So stupid! haha! And i have no idea what the carbs are off :( Also ive bought a regulator for the pump ive got so that should be fine! Im heading home from uni on friday to hopefully get her running! Thanks again guys!

One more thing, does anyone know what i could connect the fuel pump to in order to turn it on? Does it have to be switched when cranking or when ignition and cranking?

[jeremy fisher]

I used the feed for the rear window demister at the fuse box as I didn't need it any more but any ignition live (black) should be ok. Just make sure you take it after the fuse so it is still fused. You also may need to up the Ampage of whichever fuse you run it through but I'd see if it blows first. May be an idea to have a switch as well so the pump can be switched off separately if you're sat with the ignition on but not running. And if you put it somewhere out the way it can be a kind of imobiliser, just one that lets the thieves get down the road a bit with the fuel in the carbs!! better than nowt though. Also one of my mates used to run bike carbs on his golf and he left the pump on, nipped inside his house to grab something, came back out to start it and it hydrolocked because a needle valve had failed and it just filled the cylinder with fuel. dead engine for the sake of a crappy needle valve!

[swedge]

i have my pump running on a switched live via relay as well as a switch so i can have my ignition on but not the pump

i have a diagram ill go find it

[swedge]

http://i818.photobucket.com/albums/zz102/balley77/untitled-1.jpg

thats if you want to run an inertia switch ignore it if you dont