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HIF 44 idle problems

Posted: Sat Jul 14, 2012 3:49 pm
by RussLCV
I have a rebuilt HIF 44 (well 2 actually) powered by a Webcom WP502 pump all is working well and fuel is getting to the carb. The engine is a midge 1275 with metro head and has been started a number of times.

The engine runs well when started with full choke and then half choke and lots of power on the throttle pedal, but once choke is returned she will not idle and one has trouble keeping engine running on throttle?

Both carbs have been fitted and run the same so this must be me and the adjusting

Any ideas please

Re: HIF 44 idle problems

Posted: Sat Jul 14, 2012 7:18 pm
by bmcecosse
Sounds like air getting in somewhere! Swamped by the 'choke' (mixture enrichment really) - but when that is cancelled - the air leak makes the mixture too weak.

Re: HIF 44 idle problems

Posted: Sat Jul 14, 2012 11:01 pm
by RussLCV
Thanks bmcecosse, but not sure what you mean. Can you point to where or what I need to do or look for?

Re: HIF 44 idle problems

Posted: Sun Jul 15, 2012 8:42 am
by MarkyB
Someone else had the same problem recently, I think something on the bottom of the carb or the heat shield was touching and stopping the carb lining up properly.
I think it was the heat shield and it just needed bending a tad.

Re: HIF 44 idle problems

Posted: Sun Jul 15, 2012 8:55 am
by RussLCV
A couple of pics and questions I hope that can be answered

see image below which shows carb set up and the plate is not fouling anything.[frame]Image[/frame]

Next 2 images show breather pipes & fuel inlet which is the bottom, what attaches to the stub end shown and the other I have connected to the front engine breather (1275 Midget) is this correct? or should it go to the carb air filter, I intend using a Mini one[frame]Image[/frame]



lastly what attaches to this on the air filter housing and where does in go on the carb. I have read Mini/Metro/Ital & Marina manuals but can find now. I suspect this is causing my idle and adjustment issues?



Can anyone help or advise please[frame]Image[/frame][frame]Image[/frame]

Re: HIF 44 idle problems

Posted: Sun Jul 15, 2012 9:04 am
by MarkyB
I think there is only one breather pipe, the other pipe was for a mid range weakening device and should be blocked off.

Re: HIF 44 idle problems

Posted: Sun Jul 15, 2012 9:36 am
by RussLCV
which one is which? Any idea? Also will this effect by idle issue?

Re: HIF 44 idle problems

Posted: Sun Jul 15, 2012 1:11 pm
by JOWETTJAVELIN
on my 1275 with same air filter these pipes aren't connected to anything either, and every one I've had was like this, so I wouldn't worry if I were you.

Re: HIF 44 idle problems

Posted: Sun Jul 15, 2012 7:05 pm
by MarkyB
I think it's the angled one.
You could always block it with your finger and see how the tick over is affected.

Re: HIF 44 idle problems

Posted: Sun Jul 15, 2012 10:21 pm
by bmcecosse
I think that brass pipe is just the overflow - but no harm trying it blocked off. The spigot on the air filter is for a breather pipe from the crankcase - which you have already connected directly to the carb.

Re: HIF 44 idle problems

Posted: Sun Jul 15, 2012 11:08 pm
by Roni
Where is the pipe on the inlet manifold going to? The photo doesn't quite show it.

Re: HIF 44 idle problems

Posted: Mon Jul 16, 2012 11:20 am
by RussLCV
bmcecosse wrote:I think that brass pipe is just the overflow - but no harm trying it blocked off. The spigot on the air filter is for a breather pipe from the crankcase - which you have already connected directly to the carb.
Is that Ok BMCecosse or should I remove................and what connects to the breather in its place

Re: HIF 44 idle problems

Posted: Mon Jul 16, 2012 11:21 am
by RussLCV
Roni wrote:Where is the pipe on the inlet manifold going to? The photo doesn't quite show it.
Brake servo

Re: HIF 44 idle problems

Posted: Mon Jul 16, 2012 11:22 am
by bmcecosse
The breather is best connected directly to the carb - as you have done.

Re: HIF 44 idle problems

Posted: Mon Jul 16, 2012 11:25 am
by chickenjohn
RussLCV wrote:I have a rebuilt HIF 44 (well 2 actually) powered by a Webcom WP502 pump all is working well and fuel is getting to the carb. The engine is a midge 1275 with metro head and has been started a number of times.

The engine runs well when started with full choke and then half choke and lots of power on the throttle pedal, but once choke is returned she will not idle and one has trouble keeping engine running on throttle?

Both carbs have been fitted and run the same so this must be me and the adjusting

Any ideas please
Check for play in the throttle butterfly spindle, was this replaced?? This can make a big difference to idling problems.