5 replies to this topic

[Shylos]

Just a quick question here... doing the initial setup on my HS4 after cleaning and I have noticed that no matter how high I screw the jet adjustment nut, the jet never gets level with the bridge, therefore it takes several full turns before the adjustment nut actually moves the jet down.

I am concerned the jet will therefore be too low to perform the initial setup - is it a prolem that I can't raise the jet level with the bridge, and if so - what is the likely cause?

The jet is a new waxstat.

Thanks for any help!

EDIT:

After looking at it for an hour, I just realised that by pushing it up flush and doing the nut adjustment it is irrelevent as it brings the adjustment nut low enough. Damn me for posting too early...

EDIT 2:

Still an issue - whilst I can set the jet height to the correct initial setup, if I rotate the choke cam and let it spring back, the spring doesn't seem strong enough and the jet returns to a lower level. Can this normally be resolved using vaseline/WD40 etc or does it normally mean spring replacement etc?

Edited by Shylos, 25 March 2013 - 04:53 PM.

[dklawson]

Have you loosened the throttle linkage so the cable and choke are not affecting it? The choke linkage in particular can make it impossible to adjust the jet.

The method should involve starting the engine, getting it to temperature, then switching off and loosening/disconnecting the choke and throttle linkages and the idle adjustment screws. Once the initial jet height has been set you connect the throttle linkage first and adjust the mixture and idle speed. The choke adjustment and fast idle are made last.

[Shylos]

Hi Doug, thanks for replying - the choke and throttle cables are not currently attached as the carb is off the car, I was looking to get the intitial setup done before fitting, running, stopping and then adjusting.

What concerns me is that is I rotate the choke back and forth moving the jet down and allowing it to move back up it doesn't move up to where it started. It seems that the jet link is catching on the choke assembly, and without manually giving it a little help the jet seems to sit lower than it should (going by measurement guides I have seen online).

It looks like it catches here:






I guess I won't know for sure until I fit it and fire it up but thought I would check in case there was obviously something wrong.

Edited by Shylos, 26 March 2013 - 01:07 PM.

[dklawson]

Thanks for the picture. It is very helpful.

Others may offer different advice but since the jet height is adjustable and the choke linkage appears to be binding on the adjacent cam... I would re-shape the choke linkage a bit. Change the bend so it misses the the cam by a little bit and try again.

[jakejakejake1]

I had a similar issue caused by a slightly bent jet, causing it to bind and not return to the correct position. That left wear marks on the jet itself and going by the fact that yours in brand new I don't think that's the problem this time - just a little heads up in case anyone else has issues like this.

[Shylos]

Thanks for the picture. It is very helpful.

Others may offer different advice but since the jet height is adjustable and the choke linkage appears to be binding on the adjacent cam... I would re-shape the choke linkage a bit. Change the bend so it misses the the cam by a little bit and try again.

Thanks for this - I have incresed the bend slightly lower down the linkage and now the jet returns easily back to the original position, plus the fast idle screw seems to sit in a slightly better position than before too. I am wondering if perhaps it was a little out of shape from earlier maintenance (or myself if I was a little too forceful when i took it on and off).

Thanks for taking the time to help, hopefully all ready to go to put back on now!

I had a similar issue caused by a slightly bent jet, causing it to bind and not return to the correct position. That left wear marks on the jet itself and going by the fact that yours in brand new I don't think that's the problem this time - just a little heads up in case anyone else has issues like this.

Yes, that would definitely cause a similar issue and is worth noting for others :)