alright guys

was chatting to cymro about this last night but was wondering if you guys had any ideas

i've t pieced my cbr 600 carbs using a low pressure facet.. but when fuel is pumped it overflows out from the little brass tubes below the trumpets.

any ideas?

Cheers.

Edited 19 December, 201114 yr by runforrestrun

alright guys

was chatting to cymro about this last night but was wondering if you guys had any ideas

i've t pieced my cbr 600 carbs using a low pressure facet.. but when fuel is pumped it overflows out from the little brass tubes below the trumpets.

any ideas?

Cheers.

i had this problem with mine. basically as u prob know the fuel return isnt efficent enough. may i suggest putting your regulator on the return pipe. i have the fuel in connected to a y brass piece with the fuel out pipe on the other side

Putting the regulator on the return side?

I can't see that diagram..

I'm not using a regulator.. I was told one wasn't needed. Erixtar didn't use one?

Cheers mate

theres no reson for the fuel return not to be efficient enough, mine runs with injection pumps supplying it, so a low pressure facet should be no issue on a return line.

hmm. I'm gonna have a fiddle and come back. Are the float levels adjustable?

should be.

Putting the regulator on the return side?

I can't see that diagram..

I'm not using a regulator.. I was told one wasn't needed. Erixtar didn't use one?

Cheers mate

i was told to set mine up this way nt had a problem since heres a moke diagram do excuse the roughness lol it may

how does having the regulator there do anything? If the return line is apparently too restrictive.. all the regulator will do there is make it more restrictive or not change anything?

How does that even run?

Unless in your case the pump wasnt powerful enough and you needed to create back pressure.

The problem here seems to be too much pressure.

How does that even run?

Unless in your case the pump wasnt powerful enough and you needed to create back pressure.

The problem here seems to be too much pressure.

I'm intrested to see if it would make a difference. where should the regualtor go, before or after the fuel pump?

I had this problem too. Nothing to do with the fuelling, id connected the fuel lines to the pipes at the top, then i noticed there was inlets at the bottom too, so i connected the fuel up to those ones and it was fine

My fuel lines are connected to the bottom (brown ones) already. Hmm

How does that even run?

Unless in your case the pump wasnt powerful enough and you needed to create back pressure.

The problem here seems to be too much pressure.

I'm intrested to see if it would make a difference. where should the regualtor go, before or after the fuel pump?

after the pump.

normally there is no need for a t-piece with a low power pump and regulator.

fixed the fuel leak problem.

When I connected my new hose the other day to the clear return line that clips on to the side of the bay I have remembered this afternoon that I pinched the brass sleeve that goes in the joint in the hope it would restrict the flow so the carbs wouldn't starve. And clearly I didn't need to! Now I can get fuel ok. I've had it started now, what a glorious noise!

However here's where I need help

I can get it to idle ok now, the butterflys are synced as far as I can see and the idle screws are out 2.5 turns each. The dizzy clicks loads though and it didn't used to with the pierburg.. any ideas? I've set the timing to base 2 deg BTDC for now. Could the clicking be something to do with the pierburg wiring that's no longer connected?

When I rev the throttle, the plastic sliders flutter.. and then they pop and the engine dies, almost like the leads aren't on right? Although they are as otherwise it wouldn't idle in the first place?

Cheers.

Edited 8 October, 201114 yr by runforrestrun

My fuel lines are connected to the bottom (brown ones) already. Hmm

Ah fair play, just the 1st thing to check as its the simplest lol. I had mine on the pipes that go to the air lol

your onto jetting now. the pop could be a lean misfire.

only way to sync properly is with a sync gauge.

I can see that it pops air/fuel vapour backwards out of the trumpet when it pops. Would it be worth winding the idle screws out a tad more and seeing if that helps?

Also the clicking from the dizzy is worrying. If I disconnect the vac advance is goes away. Ideas? Cheers.

how many cylinders are you getting the vac signal off?

the screws only deal with idle mixture there is a link between acceleration and the idle mix but it only comes in when you floor the throttle from standing the main jet that takes over after that.

just cylinder number 1.

Well it idles ok.. Although there is a sputter of liquid from the exhaust and it pops a little bit, so I hope that is fuel and not coolant (we did the head gasket at the same time)

When I rev it the slides don't get past halfway and it dies.

ideally you need a signal from all 4. I'm running on cylinder 2 & 4 after a t-piece snapped and get the occasional clicking, with all 4 it was fine.

could be spring rates then. if the spring is too strong it will need more effort to open the slide. do you know what size the jets are?

Do I need it on all 4? Is that why its clicking because its getting on/off vacuum?

I don't.. I'll take it off tomorrow and check. I'm just trying to get it running well enough so I can drive it 40 miles to the local rolling road.

My jets on the middle paid are 135 and outer pair are 138.

Do these need drilling? All I want to do is get it running well enough to drive the thing.

With the idle screws out 2.5 turns the exhaust pops.. does this mean its lean or rich? And the carbs will rev higher without dying when the engine warms up (yesterday I was messing with it cold) although they still spit out of the trumpets although they don't pop like they did. Ideas?

when i first put bike carbs on my old engine they used to backfire out of the trumpets, i adjusted the timing and it stopped it. ran better too.

it doesn't pop out of the carbs any more although it does pop in the exhaust and timing advance/retard doesn't change it. Basically fiddling with the pilot screws at the moment.

Just stoked I've got it idling! and it now revs up but goes pop pop pop

ah well exhaust backfiring is cool! lol