Ferret Stuttering

[Matthewc66]

I recently got my Ferret roadworthy with the help of my mechanic.

 

I have a small issue and before I asked him to look at it I thought I would post to see if there is an easy answer.

 

The Ferret runs excellent through the gears but when I have it in top gear and try to achieve top speed, approximately 50mph the engine starts to stutter, almost like it is turning off.

 

When I go back to 4th gear and slow down a little the engine runs perfectly again.

 

I thought:

 

1. Maybe there is a clogged jet that only shows itself when I am in top gear?

2. Maybe there is some type of governor or top speed limiter?

 

Any thoughts?

[griff66]

gov operates at i think 3750 rpm.

[Matthewc66]

I didn't pay attention to the rpm's but at 45 mph I am thinking I wouldnt hit the governor.

 

I read that top speed is around 55 mph.

 

I will drive it tomorrow and check my RPM's..

[fv1609]

I would check the gaps on your points, maybe the heels that rub on the distributor shaft are begining to wear & your gap is closing. Also check your condensor is still 100% perfect.

[john fox]

the governor is actually the rotor arm inside the distributor - assuming you have an original rotor arm!

 

the rotor arm has a spring loaded section which grounds (earths) the circuit at the relevant revs and obviously therefore stops the spark circuit from being completed - I can't remember the rpm for when it operates, as I have only hit it once and that was not an experience to be repeated (committed to overtaking on a motorway :red: )

[sirhc]

There are different rotor arms depending on which vehicle the engine is installed in. It might be worth checking you have the correct one, the rpm is stamped on it.

 

Chris

[fv1609]

Bear in mind that the cutout speed marked on the rotor arm is the speed of the distributor, which is half the engine speed.

[Marmite!!]

Good reading here from Clive... http://www.hmvf.co.uk/pdf/IGNITIONMATTERS.pdf

 

Fit electronic ignition & eliminate the points etc...

[Adam Elsdon]

A friend had a very similar sounding fault, it would run sweet then start cutting out, we checked the points, tested the condensor with a Megger and tested the Coil, all were fine, we then pulled the carb and opened it up, turned out to be clean, checked the filter in the union, and it had trapped a tiny bit of grit, but not enough to cause it any concern, all very strange?

 

We decided to use an airline and back blow out the fuel pipe from the inside the ferret at the fuel filter (which was clean), disconnecting a union, and leaving the carb union end open, with a catch container to catch the fuel that came out.

 

The amount of sludge and grit that came blasting out was staggering! the tank looked clean and nothing in the filters at the carb suggested the state it was in, so somewhere in the pipe, through the fuel pump and up to be carb had a large amount of heavy sediment restricting the flow.

 

We think that at some point, a load of crud had got into the tanks, either from dirty jerry cans or just been left open or abused, then the fuel system had been serviced, probably in an attempt to make it run better, but left all the heavy sediment sat wallowing about in the lines.

 

It now runs absolutely fine, with its perfectly set up and tested ignition and clean fuel system!