Suzuki Club UK

Is the piston moving up and down freely. Mine got stuck in the open position once and it wouldn't run.

Have you got any close up pictures of how you plumbed it in?

pictures speak 1000 words ed! as ferris has said, without it running stick your finger in and lift the piston, does it fall back down nice and smoothly.

you have got it hooked up to the airfilter haven't you? never run an SU without a filter, yeah its ok when your setting it up etc but I would never go out on the road without one as all sorts of crap will get in there.

what have you done with the fuel overflow, does it just run down to below the engine.

there's nothing wrong with the carb not having an insulator between it and the manifold, if anything it will stop you getting carb freeze in the winter.

this website might help you, you'll recognise the kit you have

http://www.sj410.co.uk/su/

Okay, there's one thing, I didn't add an extra 'T' in the breather hose, I just blocked that off, so that might be the problem.

I've just been to take photographs of it to post in this message and it started up fine just now. Yesterday it literally was more dead than Elvis.

Here's how it is plumbed in. It's bolted to the manifold, it's got the ram-pipe bolted on the other side and the airbox hose fitted. The fuel inlet is connected to the fuel pump outlet and the overflow uses the overflow hose from the pump. The fuel pump's overflow has been blocked off. Other hoses that have been blocked include the vaccum advance and the breather, along with two others I couldn't identify. One of these is down by the fuel inlet and the other on the far right of the carb next to the manifold (has the L shaped hose blocking it.)

These carbs rarely disperse any fuel from the overflow so that needs an open pipe hanging down below the engine etc. Put the fuel return back on the pump, with it blocked you are going to be pumping too much fuel into the carb, hence some of your issues with fuel being dumped into the air box when you turn the engine off.

Found these, any use?


1 is overflow
2 is breather
3 is fuel in
Little one at the top is the vacume connection

Right, mine looks more like the second one. So I've put my fuel return hose on my float air vent?.....Herp derp. What should I do with this vent then?

How did you find that diagram, I went looking and could find none of my carb.

You sure about just having an open hose for the overflow? Sounds like a fire risk if it decides to dump a lot of fuel.

Im going to go with Scottie and say that its too much pressure due to no return pipe causing intermittent overfueling.

Either that or perished o-ring on the choke if its old enough? That made my hif44 really intermittently crap!

I just ran my overflow to the hole behind the headlight to ditch fuel into the drivers arch if it ever overflows. That way I know I will smell it straight away and its well away from hot stuff.

Strange it just let me post without the "there has been a more recent post" message.

As far as im aware the float vent is the overflow as per the first diagram so maybe try blanking the overrun one, reconnecting the fuel return to the pump and fitting an overflow to that vent as i described in my last post.

Unless someone else knows better

Dan

dan_2k_uk wrote:Strange it just let me post without the "there has been a more recent post" message.

As far as im aware the float vent is the overflow as per the first diagram so maybe try blanking the overrun one, reconnecting the fuel return to the pump and fitting an overflow to that vent as i described in my last post.

Unless someone else knows better

Dan

remember this is the hif38 not the hif 44 dan, the pipes are all different that float vent on the side is like those two holes on the intake side of the hif 44 so you don't need to drill those out in the airbox adapter ed. the float air vent should just be left open in your case, if you were running a snorkel you could pipe it up somewhere high to not let any water in while wading.

like I said, these carbs should not really let any fuel out of the overflow, if they do it means there is something wrong, it's more of an emergency thing. it's perfectly safe to have it hanging below the engine dumping fuel out underneath if it ever does.

oh and type hif 38 into google images

Float vent just suggests its for the float chamber but when you look at it it does look like the casting goes to the piston vacuum holes aswell.

Thats the problem with random internet diagrams you never know if its accurate or not.

There is full diagrams on burlens site but Im on my phone so might not work. Will try.

Okay, I've put the overflow to run out of the drain hole behind the headlight, unblocked that vent and re-connected the fuel pump's return hose.
I'm going to take it out for a test drive.
Hopefully it'll run nice semi-permanently now and not just for 12 hours.