Lumpy running (still)

[mattsay]

Hi Guys,

In an effort to look for obvious (and low cost) solutions to my poor running, can anyone tell me how much fuel should be in the fuel filter (the one in the engine bay near the inertia fuel cut off switch)?

I have posted a few different threads on my poor running, from Timing to Carb setting to Ignition, but if possible I wanted to eliminate any fuel starvation issues before pulling my hair out on other more technically demanding possible issues.

Is there a reasonable test to perform?

Cheers,

Matt.

[Peter Hills]

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Matt,

One simple test is to remove the outlet pipe from the filter and run the pump, while collecting the fuel in, say, a jam jar. Just how much fuel you should see is difficult to say but the pump is rated at 7 galls/hour - approximately 1 pt/min. 20 sec, half a jam jar, perhaps.

Hope this helps

Peter

[mattsay]

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Thanks Peter, I'll give it a go. At least that's something quantifiable. I had previously read "a steady flow is required" but that's a little ambiguous.

I take it then that the filter won't be full all the time?

Cheers.

[Guest]

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Hiya, for some reason the level of petrol in the filter is not a guide to the flow rate, as long as it's not empty. If it's started to turn brown, get rid of it and don't replace it with the cheapest option, any of the respected suppliers can let you have a good one, sometimes the cheap ones break up and can block the needle valves. Martin.

[mattsay]

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Hi Martin,

Just tested the pump and it's fine. I get a good steady flow and filled about 1/3rd to 1/2 litre in 30 secs or so.

Filter clean, fuel clean in bottle.

Car seems smoother today already and it hasn't yet warmed up. I saw in a previous thread that when the Aldon is fitted there are two tiny lugs/lumps around the area of the dizzy plate (where the plate slots in to dizzy body) and these may foul on the bottom of the two base plates making the unit not sit flush. I did as previous people have and filed them off. Plates were immediately better (i.e. flat) and the magnetic ring dropped a tad further and also the rotor arm.

I also removed the red ignitor wire from the +ve side of the coil and fixed it to the switched side of the fuel inertia switch to make sure there is a full 12 volts to the ignitor. Other benefit - fuel cuts out (presumably in an accident) and so too does the ignition. Thanks to previous threads for that too.

I have slackened the dizzy bolts ready for timing (properly this time). I hope to have better news later.

Cheers for now.

Matt.

[mattsay]

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I still can't get this mother running right - I am sure it's me, but at the moment me is all I have!

After disconnecting the choke cables, throttle cable and other linkages I am finding it difficult to balance the carbs. What ever I do to the slow idle screws i can't get the same hiss from both carbs (I am using the hose method). The driver side carb is already down to the stop (spring fully compressed) and it is still quiter than the other one. Orshould the hiss get louder as the slow running screw is turned anti-clock?

I also now can't seem to adjust the mixture enough to stop whitish smoke coming out from the rear. Is something sticking on one carb which is buggering everything up?

My head hurts.

[stustag]

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Hi Matt

Follow these instruction and you should be Ok if not I might be able to come down next week and have a look for you.

[stustag]

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Hi Matt

Follow these instruction and you should be Ok if not I might be able to come down next week and have a look for you.

[Stagdad]

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Matt ,I think you need to nail the timing first ,If you are certain the pulley has slipped round i would tempereraly remark TDC by using the screwdriver method to find it through the front passenger bank spark hole.then set it to 12 deg and plan on getting a new pulley ASAP.

Cheers Steve

[stustag]

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Hi Matt

You have taken the cam cover off and made sure that both valves are shut and the piston is at the top? other wise it is on the inlet or exhaust stroke!

Stuart

[Arbman Al]

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stustag wrote:

Hi Matt

You have taken the cam cover off and made sure that both valves are shut and the piston is at the top? other wise it is on the inlet or exhaust stroke!

Stuart

You can just put your thumb over the plug hole, and as you turn the crankshaft feel the pressure increasing.

On your carbs check that the little brass thingy that the idle screw pushes on is freely moving.

Al

[Arbman Al]

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Stu,
Did you post the instructions twice because we got twin carbs?
:P

[Peter Hills]

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Matt,

Are you setting your timing on No 2 cylinder? This is the front cylinder of the left-hand bank.

Peter

[mattsay]

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yes definitely on no.2

cheers

[mattsay]

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Hi Stuart,

I will have another go tomorrow and try to nail it. I hope I have mistaken TDC using the screwdriver method.

I had already turned my attention to the carbs, removing the choke cables (which I already replaced cos the passenger carb side was broken and too short), throttle cable and linkage rods. I failed to get exactly the same hissing from both carbs but it was relatively close.Any idea why one carb hissed louder than the other, despite changing both idle screws many times?I did manage to get a decent tickover, pretty constant so I decided to put everything back and then attempt the fast idle and then mixtures.

When i tried to reconnect the throttle cable, I realised that this cable was also too short and to get it fixed would have meant completely disrupting the carb idle settings. New cable on order from Hart's hopefully arrive Sat. This does mean that the carb settings when I bought it must have been wrong.

I would really appreciate you coming down if I fail to get it sorted. Can I let you know how I get on. (I would obviously cover your expenses)

Cheers,

Matt.