flat spot

[matt-me]

My two penn'orth :

I had the exactly the same issues, changed from 009 to SVDA, changed leads, plugs etc at the same time and the problem went away. As someone else has said, a much smoother acceleration is now achieved and much nicer to drive.

Check all the screws/bolts used to blank things off are big enough, ie don't let air past.

A question to the forum, could it be anything to do with the thermostat not working properly? Atlime said at first all seems ok when warming up but when warm it starts to happen (thermostat belows not opening therefore not pushing to open up the flaps?), just a thought.

Good luck

 

[aogrady]

Aaron,

Just check with a mirror and can see the jet pointing down and it does squirt fuel ok..

seem to squirt it towards the back of the carb (back of the van direction)

is that right?

Here is a pic of the left side of the carb

Hi!

Just below the silicon on the front of the carb - is there a screw missing - looks like a threaded hole?

And any play in the throttle shaft will cause a flat spot - Nick J has just rebushed his carb. See his post here:
http://forum.earlybay.com/viewtopic.php?f=31&t=14844&start=0" onclick="window.open(this.href);return false;

Cheers!

Alistair

 

[atlime]

That threaded hole is blanked of like it never had anything in there....Put my finger over it and no suction

Have also sprayed wd40 over the blanked pipes and the silicone to make sure no leaks and seem ok (engine doesnt seem to get any faster)

Am currently trying to get some rubber pipe to connect the air filter flapper to see if it helps...But the 3 car spares places ive been in dont have any :shock:

 

[TheBusDriver]

You mention that you have electronic ignition, That is good no need to check the dwell now.
Have you checked the timing yet?
It should be set to 28 degrees at full advance.

 

[atlime]

I havent checked the timing but the guy I got it from had checked it to try and sort the flat spot.


I still want to check it but dont have a clue how to do it really...I did it once about 18 years ago :shock: so dont have the confidence to try....Ill rope someone in on that one so I dont make a mess off it!

 

[atlime]

What is Dwell anyway?

I was looking at a thread the other day that people were on about it!!

 

[TheBusDriver]

Dwell refers to the amount of time the points are open.
No need to worry about it with Electronic ignitions.

I wouldnt trust that the P.O. set the timing correctly.

 

[crewcab]

the timing is right, but it was set a 32 degrees max, made no difference advanced or retarded, valves set correct, new bocar carb with no wear in the spindle, i've built and raced engines but this had me stumped, the first thing i would do is change that fannymold and conect those pre heat pipes up and change the gasklets under the manifold ends, the AC/ pump jet was working correctly too. bit of a head scratcher :lol:

 

[noddy]

Is the accelerator cable set correctly, ie with pedal to the floor and 1mm clearance between throttle arm and carb body?

If its got a new carb I would guess it has do do with the advance mechanism in the dissy, either advancing to fast (bad news if it is, it will lead to pre detonation) or sticking advance weight that only free up over a certain rpm.

I would stick another dissy on and see if it clears the problem.

What are the plug like after a run not after idling, run van some where with a layby and turn engine of whilst throttle is open and coast into layby and pull plugs (if you let it go onto tick over it wont tell you what the running mixture is like).

Its a guess but if its not the dissy it could be air being pulled in somewhere and checking the plugs will tell you if the engine is running lean if they are white.

 

[atlime]

Took me a while to get round to it but......

I have replaced the 009 dizzy with a bosch vacumm advance dizzy and its so much better already...I have yet to check the timing as had to move the dizzy around to get it started but it seems pretty good but will check it anyway

Thanks for all the advice from everyone, I have learnt how to change my dizzy and have a good idea how to check the timing now

I had managed to drive with the 009 by flooring it till I get past the flat spot but it loads better not to have to do that.

Thanks again

 

[Tofufi]

Sorting out the hot air connection to the air filter will do you a world of good too

The plastic connection on the top of the filter goes to the plastic connection on the 'snout', the brass connection on the top goes to the inlet manifold port below the carb.

The large air pipe should go from below the snout to a tube which goes under the rear tinware.

Oh, and I would check the timing before you go on a long drive, it'll cook the engine fairly quickly if it is too far out

 

[Lang]

As I stated on another post - Junk those 009s - they're only any good for racing. If you want a smooth drive SVDA/Vacuum dizzy is the way to go. Went to bustoppover (150 miles round trip) for my first proper drive since the swap & the bus was a pleasure to drive

 

[Turkish]

Haven't reead the whole thread so if this has been mentioned forgive me, but have you checked the hose to the servo if you have one, i had a flat spot for ages.

Then out of the blue Lee at Volksmagic pick it up purely but luck