Dexta Diesel "Hunting"

This forum is about the Fordson Dexta, Super Dexta and Petrol Dexta.
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Miles
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Dexta Diesel "Hunting"

Post by Miles »

I see this topic has been up several times but the hunting bothers me...

What possible adjustments can reduce?

I have verified diaphram is good, airways are clear and gauge filter is clean

At start up the "hunting" stops in less than a minute but after it is worked and warms up it re-appears under no-load at 80% of the rev range.

I have purchased a new lift pump but have not installed yet.

In previous posts there was mention of an adjustment screw on the side of the governor housing but there is no reference in the workshop manual.

Any tips/tricks would be appreciated...

Regards

GERRY
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Post by GERRY »

HI miles ,if the engine is worn with alot of blowby it will find it hard to over come this , if it isnt , then a pin hole in the difram or in the pipe from pump to air inlet manifold could be the cause, there was alot of blowby in my dexta as the engine is worn itried all the usual an iended up changing the pump to a mech one, this stoped it as it just happens with the early injection pumps, Gerry

Miles
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Post by Miles »

Gerry,

The engine other than this issue appears in good condition....starts well, minimal smoke at startup - clearing
in 20 secs, good power and no problem with blowby.

The governor operation is too sharp so I don't think is a diaphram issue but will do a physical inspection to be sure.

Regards

naildriver
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???

Post by naildriver »

Can someone define "hunting"?

Foxen
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Re: ???

Post by Foxen »

naildriver wrote:Can someone define "hunting"?
I'd define "hunting" as rough idling, the engine is "hunting" for the rpm you've chosen with the throttle lever but overshoots it and then the governor will correct it downwards and undershoots...

ex. you aim for 800 rpm and the tacho shows the engine fluctuating between 700 and 900 rpm rather than running steadily at 800 rpm...
Essex Lily - Super Major -62 (No. 1618924)
Mr Fordson - Super Dexta -64(dad's)
"Si is est non infractus , effrego is quod animadverto si vos can redintegro is!"
<Ut simplex, validus quod constanter ut ferrum talea campester = Super Major>

BarryT
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Post by BarryT »

Hi,

I was under the impression that if it's not hunting then it's not a Dexta. A hunting Dexta is as common as a Major with a clattering drive coupling.

Regards,

BarryT

Foxen
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Post by Foxen »

BarryT wrote:Hi,

I was under the impression that if it's not hunting then it's not a Dexta. A hunting Dexta is as common as a Major with a clattering drive coupling.

Regards,

BarryT
Hehe
Essex Lily - Super Major -62 (No. 1618924)
Mr Fordson - Super Dexta -64(dad's)
"Si is est non infractus , effrego is quod animadverto si vos can redintegro is!"
<Ut simplex, validus quod constanter ut ferrum talea campester = Super Major>

Jos Cuypers
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Post by Jos Cuypers »

Barry is right.

Dexta with pneumatic governor is known for this hunting.
Rgds
Jos

My dexta has 32 Horse power, but a donkey behind the steering wheel.

Wee59dexta
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Re: Dexta Diesel "Hunting"

Post by Wee59dexta »

I have always been led to believe that dexta's 'hunt'. In fact i don't believe I've ever heard a dexta running which didn't. This makes me laugh because my Dad has always complained that his dexta didn't 'hunt'. My uncle years ago worked at the governor until he got it to stop. It used to do his head in while it was idling in the shed.

So my question is, If my Dexta doesn't hunt should we leave it alone?!

blue32
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Re: Dexta Diesel "Hunting"

Post by blue32 »

Hunting is most common coming from diaphmgram is unstabile... how can it be ustabile?? -it is two sides on the diaphmgr. 1. the side nearest the pump has a litle filter who can go full of dirt... 2. the outer side of diaphmgr. has a pipe to the inlet throotle "vakumpipe" and if this is stoppped with dirt?? it will also affect the Diaphmgr.
And 3. if it is some leak in the rubber diaphmgr. it will also affect hunting. (unskreew the vakumpipe and the stop wire too, drag the stoplever to the stop position, put your thombfinger on the hole for the vakumpipe, and let the stoplever go free again, if the stoplever goes slowly in position again, the Diaphmgram is good enough, if the stoplever goes quick back again, while the thumb is holding the hole... the Diaphmgram is leaking.
This is the usual prob,s for hunting, i think.

Blue32

JC
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Re: Dexta Diesel "Hunting"

Post by JC »

As far as I know, all Dextas hunt. Its probably because they don't have a damping valve in the governor like a Major does. That's why a Major has 2 vacuum lines and a Dexta only has one. My Dexta has a pronounced hunt when it is cold, but after it warms up, it's barely noticeable.

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