They don’t have a good reputation. Why do HIF44E ORFCO valves fail (or do they)?

[HIF44E]

They don’t have a good reputation. Why do HIF44E ORFCO valves fail (or do they)?

First post - here goes... In short I understand in Monty or a Maesty circles the consensus is you run for hills before you leave an ORFCO valve fitted or jam it closed and cap the wiring? I see HIF44E carbs on eBay fitted blanking plates etc.



With an HIF44E, a Monty or Maesty has an ECU set to pulse the ORFCO on overrun. Thus weaken the mix. On Sherpas ORFCOs were used as an overrun shut-off?

https://maestro.org.uk/forums/forum/...wiring-colours

https://maestro.org.uk/forums/forum/...covered?t=3102

https://maestro.org.uk/forums/forum/...rfco-valve-how






They get sticky or get stuck in the open position. Why, what exactly goes wrong with the ORFCO?

i) Do they burn-out the solenoid coil?
ii) Does the rubber-seal go AWOL?
iii) Do they clog which causes i) and/or ii)?
iv) Or is the clog a symptom of i) and/or ii). Which comes first?
v) Another reason?

Is their reputation fair? Do they get a bad rap when cleaning and a dob of silicon-grease would keep the O-ring soft and the solenoid moving?

[HIF44E]

Ahhh. I've just stripped mine down. I can answer my own question.

It's an appalling bit of design. Minded that I'm a design-engineer it says very little for my profession. Whilst carbs are not my thing ( I do white goods, mostly electric-toothbrushes; typanic-thermometers; washing machines) I'm still able to see why this 'thing' will never work. Not for long anyway.

Thus the solenoid shaft requires lubrication and that gets blown out by the passage of air and a heap of airborne-crud finishes the job. It cannot work and never will. Minded that many a design brief is to make something last the warranty period, and milk the hapless buyer consumerables in the bargain, you could argue this is excellent design, only I can't see it doing as much as that?

I'm going to make-up my own blanking-plate with 3 ports. Thus shove a standard 3-way solenoid valve on there and remove the SU 'thing' completely. Wire up the existing wiring to 3-way solenoid instead. Thus a proper functioning ORFCO valve that can't stick. And unlike the 'thing' will cope with a fair lump of clogging, and you can clean it anyway.

Machinist will want min. quant. Reckon it'll cost £25 a plate (for 3 x ports) + £5 delivery if I do them as a batch.

Anyone in on this for one of your own?

If so, put a "Yes please" to your replies.