Troubleshooting no start issues _UPDATE posted

[71MKIV]

Re: Troubleshooting no start issues

Though the directions say not to I have found that if you mix this up in an old pot (one your wife won't shoot you for using) and boil the carbs in it for about 15-20 minutes they come out spotless. Just be sure all the rubber parts are out and you do it outside.

:laugh:


You just do it on the powder coat oven in the shop!

 

[eschneider]

Re: Update - Success!!

I did run it down the street last night and there was very noticeable increase in power.

Hey, congrats! Well done!

I do still have some tuning to do and there is an issue with the manual choke that was installed. I will do some research on this forum for manual chokes and see I can find my answers prior to posting anything.

I'm not 100% positive on the Spitfire version, but I beleive the choke operates a "controlled vacuum leak" near the mounting flange of the carb. (visible with the choke removed). As I recall, the choke blocks the vacuum port to enrich the mixture, and normal operation is with the port open. Kinda screwy.

If you have one of the old stromberg manual choke conversion setups - uber cool, a spendy bit these days.

As for tuning, make sure you do the tuning with the air cleaner installed - they are sensitive to airflow restrictions, so if you get it perfect without the air filter, it might go wonky when you re-install the filter. More so with an MGB (really restrictive airbox), but applies to the Spit, too.

It does look like there have been many hands on this carb, to the point where I wonder if I shouldn't find a more complete original ZS CD to start with or an upgrade. The goal really is to have a reliable, fun, convertible sports car that is pleasing to look at and not a late model mass produced item that my wife and I can enjoy the scenic roads of Vermont in.

There are a couple of common upgrades for the 1500 Spit. One is to upgrade to an SU - HIF6, if I recall. I think Tom at British Miles has a couple of these left on the shelf, ready to go. For about the same money though you can search ebay UK and get the european dual SU manifold and carbs - I think you'll need the euro exhaust manifold or a header, too.

Overall, though, the Stromberg isn't a terrible carb once you've undone what was previously repaired.

 

[tdskip]

Re: Update - Success!!

The piston moves up and down now and the car started up after the float chamber got filled. Increasing the throttle, I could see the piston move up and down. Under cover of darkness, I did run it down the street last night and there was very noticeable increase in power.

Right on! I bet that felt good, eh?

It does look like there have been many hands on this carb, to the point where I wonder if I shouldn't find a more complete original ZS CD to start with or an upgrade. The goal really is to have a reliable, fun, convertible sports car that is pleasing to look at and not a late model mass produced item that my wife and I can enjoy the scenic roads of Vermont in.

Once rebuilt properly the ZS should be reliable for zipping around, but as pointed out a dual SU set up will make a BIG difference in power. That said, it sounds like the car is new to you and it might make sense to just drive her some and see if there are other things to spend money on. I'm not saying the dual SU suggested is a bad idea - far from it - just that other things may present themselves as needed attention first. There is driving to do this season still!