HELP!!! Spitting carbs - engine reving by itself

[Jan Wulfsberg]

During the winter I sent my 45 Webers to the Norwegian agent for servicing. Had the inlet manifold and the rubber rings off for cleaning. After mounting them back on, the engine (1700 X-flow, 244 cam) will not run properly at idle. After about 20 seconds after starting, the carbs start spitting, the exhaust starts popping and the engine revs to 2 - 3000 by it self, even if the idle screw is turned fully out. I can see that some times the fuel ignites in the manifold.

The jetting is the same as last year, ignition parts OK.

What can cause this problem?

 

Wulf (Viking) id=red> cool.gif

[Big Brother]

Sounds like possibly an air leak between the carbs and the manifold.

Check the rubber O rings are sealed OK

Also the carbs could be very out of balance.

 

 

Steve

www.Se7en-Up.co.uk id=green>

 

[Casbar]

Just a thought, have you adjusted the slow running mixture screws, as they will need to be re-set to get the car to idle.

 

Procdure is to screw all 4 in, then each of them out about 2.5 turns, then adjust them one at a time, rich to lean, listening for the engine idleing faster and slower etc

 

Once these are done, then check the balance.

 

Check for air leaks around the carbs as already suggested

[millsn]

I had the double throttle cable kit and it's possible that your cables get caught up under the carbs if it's not adjusted correctly. Check your throttle cables aren't just holding the butterflies open because of this.

 

Nigel Mills - 2.0 Zetec carbs

[Phil]

Did something stupid recently and learnt the hard way,

I found my carbs to be loose as though they were not tightened when fitted and with a lack of experience with webbers I took up the slack getting high uneven revs as you describe, after spending £60 for new washers and plates and lots of advice from club members this was solved leaving the carbs with 5 to 10mm of play at the end of the trumpets and my iddle back to normal and actualy running better with the freshly cleaned out carbs and filters. A shot in the dark but just incase you did not know this.

 

 

[Graham Perry]

To me it sounds either like an air leak or the carbs being mounted too tightly.

[Peter T]

Just a quick reminder, if you are having problems getting a good air seal arround the carb/manifold, do check that the inlet manifold studs are square and not bent in any way. I had this problem when a friend dropped my manifold during a rebuild and forgot to mention it to me.

 

C7 PWT X-Flow all Steel

Life begins at 40(00rpm)

[Jan Wulfsberg]

Thanks for helpful postings,but.......

 

confused.gif Carbs balanced and adjusted – no change

 

confused.gif Adjusted rubber mountings from very loose (leaks) to very firm – no change

 

confused.gif Ignition checked and adjusted, new spark plugs - no change

 

Have talked to several local “experts” but no one can find any faults, or offer any solution to my problem.

The carbs are still spitting, the exhaust popping and the engine revs by it self.

Will send the carbs back to the Norwegian Weber agent, and hopefully he can find out what is wrong.

 

 

sad.gif Lovely weather and the car still in the garage!!!!

 

 

Wulf (Viking) id=red> cool.gif