Splutterring now the carbs have gone back on?

[mazfg]

Ok, so I've put new spindles on the carbs and balanced and set the mixture but the engine now splutters when giving it some throttle and is a bit poppy whilst idling....could I have put the butterfly's on the wrong way?? This is the only thing I;ve taken off the carbs other than changing the spindles....
Typical, was runnign ok before, now it's just spluttering and quite lumpy...help please :o)

[mazfg]

Picture here show the 2 dimples at the bottom...is this right?

[Pete Lewis]

dimples at the bottom facing out is spot on.

its important the disc is allowed to centralise in the slot and the throat before you nip the screws up, with the idle screw removed or away from its stop.  

if thats all ok then I guess the mixtue is too lean

Pete

[mazfg]

Ahh, thanks Pete. I think they may have been slightly un-centralised. Have loosened the screws and put the spindles at rest and re-tightened. Fingers crossed !! The mixture screws were turned out 3 times to start with and only backed off a bit....
It ran but was spluttery at idle and with throttle, like there was too much air... I appreciate your comments....as it's still a big learning curve for me :)

[mazfg]

No joy, checked the butterflys, and totally stripped down the carbs fully....replaced this morning...still the same.......:(.   Mixture isn't too lean, as even though it's lumpy, I managed to adjust mixture by adjusting the piston up and observing an incvrease or decrease in revs.....
I'm really quite baffled by this.,.......it popping n spluttering......

Sparks from all leads are very good..........gutted......as it's a nice day and wanted to take my kids out in it......SHould've left it all alone hehe!!

[mazfg]

It did have a moment of this last week (before I'd taken carbs off) then recovered......? Could it possibly be the manifold gasket?? Is it easy to get this off?
I'm running out of ideas now.... :(

[mazfg]

Ok, so the strange thing is that although it pops etc I can still go through the tuneing procedure for the carbs.....ie: setting mixture..,.. as it goes after 3 turns out on the mixture screw, slightly lifting (0.8mm) the piston the revs will either increase(too rich) OR  decrease/ stall (too lean), adjust the mixture screw out for richness in for leaness. This still follows and found that from the 3 turns out revs increase therefore it;'s too rich, so set it so that after moving pistons 0.8mm it makes no difference to revs. Unfortunately though it's still popping and giving throttle is lumpy/ poppy......must somehow be getting air in elsewhere... Problem is, it's only the carbs that have been removed.....therefore I suspect them.....but no clearer.....

Oh why did I tinker......ah yes....because you do....  :)

[Zendervision]

Check for air leaks around the manifolds. I had popping and spluttering on my Herald just after a carb rebuild, so naturally that's what I blamed. Turned out I'd not tightened the nuts underneath the manifold properly and they'd worked loose.

[mazfg]

I'm thinking towards the manifold area now....I've never touched that area though....maybe having taken the carbs off and on a few times has caused that....having a quick look though...it all looks unmoved...

whats the best way to check for air leaks?

Thanks for the tip :)

[Zendervision]

I never had to do it, but you can spray a bit of WD40 on the joins and see if it affects engine speed. However leaks aren't too likely if the manifolds haven't been disturbed (except perhaps at the carb to manifold join). In any case I'd make sure the nuts are all tight. By the time my car stopped running the loose nuts weren't even finger tight, I don't know how loose they have to be before it makes a difference.

As the carb is the only thing you changed, keep focusing your attention here. Presumably you've been through the usual carb stuff, jets centralised and not sticking (landing with a clunk), diaphragms not damaged?

It might still all be down to the mixture. It was ages before I got mine running at all, let alone nicely. In the end it was just trial and error. That was with a single 150CD, bit more work with two!

[mazfg]

Mmmm, I stripped the carbs fully last night and rebuilt them and centred etc.....there's not much to them which is why I can't see what the problem is :(....driving me mad. I've over riched the mixture and it just idles badly until I turn it back to the good setting.......its very frustrating.....never had trouble setting them up before?? Thanks for you help :)
I may put the old spindles back in and see what happens then.....I'm running out of ideas......

[junkuser]

It could, of course, be a coincidental problem, unrelated to the carburetors.
Check the ignition side.   You say good spark but that depends how you checked it.  (Should get 5/8" spark at atmospheric pressure.)
Faulty points can do strange things when the engine is running.

Sounds as though you have pretty well ruled out carburetor problems unless you have left the damper springs out or damper oil is too light.

Will be interesting to hear what the cause is when you find it.  You will.

[nang]

Probably a silly question, but have you had the plug leads off and put them back in the wrong order. Think we're all clutching at straws now !
Tony.

[mazfg]

I put 3 in 1 oil in the dampers, been using that when it worked ok.

I have accuspark electronic ignition, so no points. Plug leads are in the correct order. The spark is very strong on all leads. Timing checked at 8 deg BTDC yesterday with strobe.

To completely rule out the carbs, have decided to take them to http://www.carbex.demon.co.uk/ as Pete Lewis said he had his spindle holes rebushed here. They're only an hour up the road from me and gonna  drop them off (after I speak with them) on Monday.... They at least can test them to check they're working and also give me new spindle bushes, as it will be worth getting these done...and double check them over..

As I mentioned, it went into this rough running a few weeks back from cold, but then righted itself after a few minutes...could be related could be not....I jsut don't know..... I will get there and keep you updated. Appreciate everyones input :)

[Mark Hammond]

Dampers should have normal 20/50 engine oil not 3 in 1.  3 in 1 won't offer enough resistance.

Mark

[mazfg]

1218 wrote:

Dampers should have normal 20/50 engine oil not 3 in 1.  3 in 1 won't offer enough resistance.

Mark

Your right, but surely not enough difference to give my symptoms....?

[Mark Hammond]

May well do actually as the dampers won't rise/fall correctly.

Mark

[mazfg]

http://www.club.triumph.org.uk/cgi-bin/forum10/Blah.pl?m-1225392248/s-0/

earlier post about this and some have used 3 in 1, was using that before and it's been ok til I changed the spindles......

I;'ve taken them off now and going to speak with carb exchange tomorrow n drop em off on tuesday to them.....at the very least I'll get my spindle holes re-bushed, which will be well worth it and they can put them on (whatever they put them on) and run them to check.

[mazfg]

Carburettor exchange are busy with a 3-4 week backlog.....so no chance of getting them looked at :(  I did speak to the guy there and he said 3 in 1in the dashpots won't make much of a difference...as long as you have something in there.

[Mark Hammond]

3398 wrote:

Carburettor exchange are busy with a 3-4 week backlog.....so no chance of getting them looked at :(  I did speak to the guy there and he said 3 in 1in the dashpots won't make much of a difference...as long as you have something in there.

That'll be why the manufacturer recommended 20/50 engine oil then.

Your guy is talking through his hat, you need the correct oil to get the correct resistance.  I am not saying that this is the cause of your problems, but it can't help.  Often with a classic car, there can be several problems causing a fault or symptom.  I think that there may well be an issue with the spindles on your carbs, especially if it was ok before they were changed, why not try another set of carbs on a manifold to see if this eliminates the fault.  I realise that it might not be easy, borrowing another set, but there may well be another member with a car in bits, willing to lend a pair of carbs on a manifold just for trial and elimination purposes.

Mark

[Jordon T]

1218 wrote:

That'll be why the manufacturer recommended 20/50 engine oil then.

Your guy is talking through his hat, you need the correct oil to get the correct resistance.  

Mark

Yes i agree with Mark, I've always been adviced to use 20/50 engine oil.  ;)

I've got a similar problem with mine, I have to set the car to idle at 1000RPM or else everytime i come of the accelorater, it'll cut out and splutter. I think i need new spindles  :-/

Jordan

[mazfg]

Ok, I'm going to put them back on again and give the dashpots some 20/50.... I wouldn't say the guy is talking through his hat, I'd hope that they know their stuff...Pete Lewis was happy with his re-bushed spindle holes! Anyway, will keep you all posted.

I'm also going to check compression on each cylinder dry and wet and give my sooty plugs a clean...although a couple are also oily too....

Manifold gasket should be on its way too, gotta fit that as well....are they quite straighforward?

[willows40]

i use 3in1 oil in the dashpots on my tr7 as it runs better with it than engine oil.

cheers andy

[100+]

I thought it was 3 in 1 in winter and engine oil in summer.

Was going to rebuild my carbs to up the mpg, but now I don't think I'll bother.  Lesson once again is, if it works, don't fix it!

Good luck mate.

[mazfg]

100+ wrote:

I thought it was 3 in 1 in winter and engine oil in summer.

Was going to rebuild my carbs to up the mpg, but now I don't think I'll bother.  Lesson once again is, if it works, don't fix it!

Good luck mate.

Yes, I know, but I wasn't happy with the running as it was, even though the engine ran and worked..... These things need tweaking, especially if I'm to do a long run in it!