Engine racing, adjustment not working/ smoke from somewhere.

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Chief
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Engine racing, adjustment not working/ smoke from somewhere.

Postby Chief » Fri Oct 12, 2007 1:06 pm

Hi,
Okay, as some of you know we've been cleaning out our carb and air filter, cleaning them up, and in the case of the air filter I removed most of the rust and coated it in hammerite no1 rust beater and black plaint.

On putting everything back on the car, we were somewhat relieved to have the engine start up without even needing the choke (the car has been out of use for several weeks now).

Unfortunately however the engine is racing along at an absolutely insane speed, to my ears at any rate it also seems to get faster, and faster the longer you leave it.

Adjusting either of the adjustment screws is making no difference at all, it continues to race away.

To add to this, on our last attempt to get it to slow down, whisps of smoke started appearing from ... somewhere, now this has got me somewhat worried, though I was told that I was a worrier and I should only worry when the flames appear).

So I guess at the end of all that what I'm really asking is what can I do about this racing engine, and uhh any ideas about the smoke?

I should also add that not that long ago a garage did some work to it (they were the ones who told us about needing new carb needle/jet etc etc) and they've sprayed the chassis (and some of the wing inside the bonnet) with rust proofing 'paint', as well as greasing/oiling up alot of places.

I admit I'm sorta wondering whether to tell one of the garages mechanics to come down to my house and sort it out :lol:

Thanks :)

Welung666
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Postby Welung666 » Fri Oct 12, 2007 1:14 pm

Did you put the big spring back between the throttle mechanism and the exhaust clamp?

Chief
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Postby Chief » Fri Oct 12, 2007 1:26 pm

yes we did, that was probably the easiest part of the entire re-assembly :)

MoggyTech
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Postby MoggyTech » Fri Oct 12, 2007 1:41 pm

Sound like the outer throttle cable is not seated in the carb flange correctly. If not that, look at the jet assembly under the carb and check it is fully up with the choke off, and that it moves down with the choke open.

If it's starting and running from cold with no choke, it is far too rich.

Chief
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Postby Chief » Fri Oct 12, 2007 5:18 pm

Okay the racing is fixed, turned out the jet nut was at its lowest point, engine sounded alot nicer when it was tightened up.

Jet doesnt return fully, comes down okay with choke but doesnt return, seems like there's a kink in the cable, so a replacement choke is probably on our shopping list.

There is currently a flutter every so often, while idling and it does sound slightly rougher, however that could be that i'm not used to our new stainless steel exhaust, compared to our old sieve of an exhaust pipe.

Oh and it no longer starts from cold with no choke :)

alainmoran
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Postby alainmoran » Fri Oct 12, 2007 5:20 pm

New exhaust? ... could that be where the smoke is coming from?

Either oily handprints or some kind of coating on the outside of the exhaust burning off?

When I've had mine apart I've usually left a few oily marks on my exhaust and it generally smokes a bit until they burn/evaporate off.

Chief
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Postby Chief » Fri Oct 12, 2007 5:24 pm

Well it had been run already with the new exhaust, didnt see anymore smoke since getting the RPM down to a much lower level.

I did read earlier that high RPM on an engine can cause it to start smoking and wondered if that could have been it, my dad reckons it was the anti-rust stuff or grease burning off.

As long as it doesn't come back i'm happy ;)

bmcecosse
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Postby bmcecosse » Fri Oct 12, 2007 8:27 pm

Just make an ajustment to the choke cable - you MUST get the jet fully home against the adjuster nut.
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Chief
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Postby Chief » Fri Oct 12, 2007 10:57 pm

we were adjusting the cable most of the afternoon. What happens is pulling the choke out is fine (jet comes out) pushing it back in the cable doesnt cause the lever to move that the cable connects to, so the jet doesnt move back up fully.

RogerRust
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Postby RogerRust » Sat Oct 13, 2007 8:29 am

There should be a liitle spring - no 5 in this diagram. It is a devil to get back on correctly, just a matter of trial and error I'm afraid until you get all the bits together with the sping in tension.
If the the jet is sticking it could be dirty - try taking it right out and cleaning it. I had to put some copperslip on to get mine to shut reliably.

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Chief
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Postby Chief » Sat Oct 13, 2007 6:11 pm

that spring was quite easy to do, compared to the smaller one just before it.

Also its a brand new jet and the carb has been thouroughly cleaned out (incl. with petrol).

The jet will go down, it just wont return as the cable doesnt move enough to affect the lever, if you use ur hand to control the choke cam lever, then the jet does go back up.

Packedup
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Postby Packedup » Sat Oct 13, 2007 7:42 pm

Did you replace the jet bearing when you fitted a new jet? It could be that's worn allowing the jet to sit at an angle and bind.

Another problem can be the little metal washer in the bottom of teh arm where the screw goes through. If it's missing (it often is on my cars...) and the screw is too tight it will cause resistance which can make the jet stick. If it's there but the screw is overtightened it can also be a problem.

If you disconnect the choke cable and move the lever down by hand, does the jet return fully when you let go? If it does, then yes it's the cable. If it doesn't, then it's not :)
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