CD150, clugded, piston jamed, Vitesse 1600, stromberg

[Flemming]

Out of the blue my vitesse 1600 lost power and stopped. Had one start with full choker on hot engine. Very high revs and a supecious synthetic smell. Ignition okay, compression okay, fuel okay. Have to had it towed to my garage. It was raining and dusk had settled on.

Suspected the diaghrams and when I lifted the top of the carbs the front one was jamed. I.e, I had to use a soft hammer to get i loose and had to use substantial force to pull it of. The piston and needle was jamed.

I replaced the piston, centralized and all, and have the piston to run alright.

Enhine wont start, no fuel through front carb - at least three dry front plugs , compared to vissible wet three rear plugs.

I checked both floath and replaced the needle valves. I blew air through visible holes, cleaned up and reassembled and fitted.

Still no fuel to the front three cylinders - dessert dry plugs.

When I blew air into tthe carb it pull up fuel fron the float chamber al right, meaning no cludging here.

How can the carb get in a state like this? Fire?

How come there's no fuel passing through the carb?

Will a sufficient big leak in the inlet manifold take all suction power out of the carb?(I did saw some unusual smokw when the engine was running for a few seconds full choked and with very high revs.)

Any comments most welcome. Thansk, Flemming

[dougbgt6]

Yes! A manifold gasket leak can cause exactly this. I tried to get my engine going after a long lay off, I had no fuel from either carb, it was the manifold gasket at fault. The gasket didn't seem badly damaged but air was leaking in like a sieve!

 

I just stripped down my head after blown head gasket and the manifold nuts were finger tight! How did that happen? They were previously torqued up. Was it Heat?

[Pete Lewis]

also check there is a welch plug in the front and rear end of the manifold  have seen these drop out and you have no chance of and vacuum

 

cant explain why a piston and needle should run ok then decide to  sort of seize up solid  ,, thats a bit odd to say the least,  jets out of line after a while is an ongoing happening with most  su stroms  and worth a check periodically but to jam is not something ive come across.on a running car 

 

have a check that a push rod hasnt jumped and locked a valve open,  where any signs of a misfire before she stopped ??

 

you say you can pull fuel up the jet with air flow , you should see the fuel a couple of mm below the top of the jet 

 

Pete

[Flemming]

Thank you for the good answers. The car's still not running. I did a manifold leak test with start spray.

And I did a complete carb cleaning.

No luck.

I will check valve and the down part of the inlet manifld.

I'm glad this didn't happen in the Alp's, where I drove three years ago:-)

 

Regards, Flemming

[Pete Lewis]

Do check both throttles are actually opening

 

obscure high revs indicates one may be free and is stuck open

 

pete

[Flemming]

Do check both throttles are actually opening

obscure high revs indicates one may be free and is stuck open

pete

Throttles working fine and as said carbs has been undertaken major overhaul including centralizing needles, which seemed to be the issue in the first place.

Fuel line's working. Compression 150 psi on all six. Spark on all six wires.

Checked inlet leaks with starter spray. No leaks.

Engine won't start by it self but starts with starter spray directly sprayed into front carb.

Obviously a carb issue, but I wouldn't know where to look.

 

Regards, Flemming

[Pete Lewis]

There is the old favorite

sliver of hose stuck in the back of the float valve

 

pete

[dougbgt6]

And, reassembling the carb to manifold gasket incorrectly.

[Pete Lewis]

Doug good idea but Flemmings CD on a 1600 wont have the bypass ports and temperarure compensators

...unless something new has been fitted

 

its all pointing to a fuelmlevel problemmon the front carb I think Pete

[Flemming]

Right, cd's with no hanky panky.

Float's not punctured and float valves renewed during this fault analysis.

Drop down float level, 18mm, okay.

I haven't replaced Diaphragm's though, but they seem in good condition.

 

May I add that there was a strange syntethic smell when the incident took place. It's told that carb fire happens, creating excessive heat and a deformed carb?

Also, it happend within a minute or less.

 

Very strange

[Pete Lewis]

so the fires out,the stuck piston is free'd the floats correct ,,the jets centralised,,,  the diaphragm is intact,

 

 

 

reckon that only leaves no fuel in the chamber  or the two  holes in the bottom of the piston are not    'engine facing'  ie diaphragm lugs  is mislocated

 

but double  check theres nothing lurking behind the float valve in the feed pipes .

 

Pete