16 replies to this topic

[Trissy B]

Thinking of getting one as swapping the pump. 3 questions.

How do you actually adjust the pressure? From the photos I can't see how you would and is there accurate settings?

If you get one with 8mm fittings,can these unscrew so you can use 6mm instead?

I think the small has a 65mm bowl. Guess this is fine for the min but is the bigger OK too? (85mm).

I've found a second hand one at 85mm bowl x 8mm in/out. Any experience very welcome.

[hazpalmer14]

You attach a fuel pressure gauge to the output and there will be a screw that winds in and out to adjust pressure.

[imack]

Some come with a tapping in the top where you can screw in a pressure gauge. I drilled and tapped mine to accept a gauge to set the pressure via the adjustment screw and lock nut on top of the unit. Remove gauge once set and screw in a blanking plug.

[Trissy B]

Thanks guys didn't realise you had to buy the pressure gauge too.

[Trissy B]

This is what I am looking at. Not sure if it's too big for 1275 on Hif44.

https://www.ebay.co....4.m46890.l49292

[imack]

I think mines only the 65mm version, fittings are 8mm but located differently to the one you're looking at.
The one in your picture has the plug that can be removed and a gauge fitted.

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[nicklouse]

This is what I am looking at. Not sure if it's too big for 1275 on Hif44.

https://www.ebay.co....4.m46890.l49292

Buy new. The diaphragm could well be rotted.

[no66]

Some of them come with a 6 to 8 mm combo fitting. 

If I remeber correctly the base setting pressure will be in the ballpark for an SU at 3.5 psi that is lower than most electric fuel pumps

 

Get the 65mm glass bowl.

Edited by no66, 11 January 2021 - 11:11 AM.

[Ethel]

You used to be able to pinch them off Alfa's back in the day. You don't need a gauge, you can adjust it to starve the carb then bring it back just enough, but a gauge needn't be expensive.

 

https://www.fuelpump...arts-5084-c.asp

 

I think Merlin carry some parts too

[Trissy B]

Great thanks for the replies, I think I will go for a new 65mm one.

I thought the pressure for a hif44 was more like 1.5 psi??

[m445]

I recent got a pressure regulator and filter to feed the HIF44 carb.  This regulator has markings to set pressure.  I will add pressure gauge to check also.

 

Mr Gasket 9710 pressure regulator

https://www.amazon.c...p_MgB.FbZQ56XBQ

Mr Gasket Filter 9706

https://www.amazon.c...p_2jB.FbMTJGCY6

 

 

[PACINO]

Hi. I have had a Malpassi Filter King installed in the Mini for years. It was the glass version, which is very useful to see the status of the filter.

https://www.minispar...|Back to search

I recommend that you buy it with a pressure gauge, and thus regulate the exact fuel pressure that your carburetor needs.



Regards

[Ethel]

Great thanks for the replies, I think I will go for a new 65mm one.

I thought the pressure for a hif44 was more like 1.5 psi??

I don't think pressure will be that critical or a universal constant for all SUs.

 

You'd have to look at the float's displacement, leverage, valve orifice area etc - but I'd hazard a guess it'd take quite a bit more fuel line pressure to force it to open.

 

Where the pressure will matter is in allowing a high enough rate of flow when the float drops and that'll depend on the rate the fuel is sucked in to the engine i.e. its horsepower.

 

Even so, never heard of any needing more than 3psi

[MiniMadRacer]

Minor comment but "racer" rules dont allow the glass bowl (usually) for obvious "breakage reasons", fine for the road I believe but do be aware they break easy, so once fitted be careful when spannering in that area, only needs a little tap from a spanner or a ratchet

[cal844]

Is it possible to buy a metal bowl as a replacement for the glass item?