the 3/4 point unit should still stay extended for a couple of seconds though, if it is immediately retracting then the problem lies with one of the electrical thingies behind the carb, you should hear them click with the ignition on. Plus by 'fully retracting' do you mean still extended by 8mm or so, or completly withdrawing into the housing? If you dont get continuity between the red plug on the autochoke and the metal housing of the choke cover then the heater spring is shot, but I doubt it woudl cause this problem as it would take a while for the heat to have a noticable effect, starting straight away from cold would not be effected. I would take the waxstat off the front of the carb and check a) the pin extends as the engine heats up, and b) the operating pin is present in the carb itself. This is what the waxstat presses against to control the idle, you should be able to push it in with your finger and feel some resistance. Last thing, when the engien is hot and idling, manually close the choke flap on the top of the carb, it should be easy to sut till the last 5mm or so, if it closes completly then the pull down unit isn't adjusted properly or its broke.
Just taken the waxstat off, that was fun ! popped it in some boiling water and the pin extended slowly so it was about 3mm proud of the black plastic case. Is this normal ? The rod that this pin pushes in the carb seems to be seized and wont move. Maybe this is the problem ?
Good work fella! Yeah the screws are a bit tricky to get a tool on, especially the lower one... Anyway, the pin should extend a lot further than that, so it looks like a dead'un. The 'extension piece', for want of a better word, should move freely within its little plastic sleeve, although there's a strong spring pushing it outwards, against the pin of the waxstat. If those bits are seized in an 'inward' position, causing the warm-up cam to be rotated clockwise to a 'warmed-up' position, that would explain your problem. Does the area where the 'extension piece' sits look corroded? Maybe a coolant leak past the waxstat's internal o-ring seal? Could be hard to see in-situ, little mirror and torch maybe?
yes, it is corroded. There has been a leak round that area. The extension piece is really tight in its plastic sleeve. I can just about move it with a screwdriver, with some force. cant imagine the waxstat rod being able to push it. Also the waxstsat hose connections have broken off inside the hose. Any ideas how to free up the rod ? I'm off to GSF for a waxstat.
if you have enough sticking out try pullin it out with pliers, its not (supposed to be) attached to anything inside. once out clean the pin & hole as best you can so the pin can slide in an out freely till it meets the linkage inside the carb. if its still really stiff then consider lifting the carb off the flange and giving it a good going over underneath with carb cleaner then a light greasing on all the linkages. Be aware when you tip it upside down fuel will come out, so have a bowl or something ready to catch it all. The fuel will also work great for cleaning up the carb if you dont happen to have any carb cleaner I'd chuck a new flange seal on there while you're at it, not that expensive from AVS
i tried moving it with pliers, no luck there. really need to have a go with a spanner to try and rotate it round, as it has a couple of flat sides to get an adjustable on.
You get a new extension piece and the plastic bush it goes through with the waxstat, so it'll just be a matter of clearing out the hole they go into hopefully. As John says, this may be easier with the carb off the car. Make sure you get any debris out of the hoses if poss. before refitting to your new waxstat.
just been to GSF , closed ! So when you but a waxstat you get the white plastic insert and the metal extension rod with it ? Really don't wanna take the carb off, gonna have a once i get a new waxstat.
Yup Ring 'em to check if you want to be sure, but I certainly got all those bits with mine (from GSF).
just got a new waxstat from GSF. decided to try it out in a mug of hot water. The rod came out fairly quickly but hasn't returned once it had cooled down. Is this normal ? If it stays like this then surely it will not control the idle and will be stuck in the slow idle state. What do you think guys ?
Ahh....yes of course. doh. gonna fit it tomorrow. hopefully it will fix the cold starting probs, just in time for the cold weather. Btw, got a new metal rod, plastic white sleeve and 2 new screws with the waxstat. just gotta get the old one out. gonna be fun :-)
fitted the new waxstat today. couldn't get the old plastic guide out, so left it in. The little rod was very tight in the plastic guide so had to file quite abit off the sides so it would move freely. Ran the car up to temperature and could see that the waxstat had pushed the rod out. Hopefully once cooled down the spring on the lever will push it back. Wait and see if it all starts ok tomorrow morning when cold.
I'd think it will be a good idea to get a bit of grease on this new filed-to-fit extension piece, if you haven't already. That should lube it a bit for ease of motion, and also provide a bit of corrosion protection for the future. Not necessary normally, but in your case I think it could be good. You can probably get away with pushing a bit of grease in from the spring end, rather than take it all apart again. While you're there, put a drop of grease on the surface of the warm-up cam, where it will bear on the pin/stop on the throttle mechanism (where the 'cam' arrow is pointing in my fuzzy pic in post #3). Best of luck for the morning.
Started the car this morning and it didn't run too well. kept trying to stall. Once warmed up I could see the extension rod poking the lever out. Looks like the waxstat is holding the rod out too far when the engine is cold. When I fitted the waxstat , the little rod that extends out of it was about 3mm proud of the plastic housing. When i screwed it into the carb it was pushing the extension rod back against the sprung loaded lever. Is this normal ? Maybe i need to cut a bit off the extension rod so it isn't pushing against the waxstat when cold. ? What do you think ?
Waxstat sounds normal to me. Did you ever check out the pulldown unit? If that's bust it could explain your residual trouble.
I will check it again, I checked it a while back and it seemed ok. Maybe the rod is stuck out in the plastic sleeve ? When i removed the rod the other day when i changed the waxstat the idle went right up, as i suspect it should. I will take the waxstat off when its cold and see where the rod is ?
Possible I suppose, given the previous trouble in that area. Correct. Check that the ends of the spring look to be located in their correct positions, and that the adjustment screw that connects the cam to the warm up lever isn't loose. I'll try and get a piccy of this stuff on a spare carb that I think might be in the cupboard in the corner... I'm looking forward to hearing that you've finally cracked this... but not as much as you are, I suspect Edit: Here you go: The adjustment screw shown may well not be in a normal position, as I've never had that carb on an engine, and don't know its history; but check yours isn't loose!
When i looked at it yesterday i could see that the end of the spring that moves when pushed by the waxstat wasn't butted up against the carb , as it is in your photo. It was about 3mm forward. once the car was up to temp you could see about 5mm of the extension rod , that had been pushed out. When the engine is cold, should it look like your photo ?
