Left pot miss fire back fire

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Galactic Greyhound
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Re: Left pot miss fire back fire

Postby Galactic Greyhound » Fri Aug 25, 2017 5:50 pm

Did you clean out the Emulsion Chamber and the Emulsion Tube on the LH carb?

You need to remove the Emulsion Tube to do this so be very careful you do not damage the threads in the carb body if they are seized.

If seized, you might consider boiling up the carb body in water to free the threads and minimise the risk of damage (Jaythro has a method for this).

See the 'Carb Cutaway' diagram posted previously - the Emulsion Tube is the part the Main Jet is screwed into and which itself is screwed into threads at the bottom of the carb body Emulsion Chamber.

By removing the Emulsion Tube you can clean the Tube, the Chamber and the Air Inlet port going into the Emulsion Chamber.
This is not possible unless the Tube is removed.

First note the depth of projection of the Emulsion Tube Nozzle into the carb venturi - this Nozzle is a separate component which may or may not come away with the Emulsion Tube and can be incorrectly fitted on reassembly if care is not taken in its orientation and fitting.
Ced.

R1100RT 1996.
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Jet
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Re: Left pot miss fire back fire

Postby Jet » Fri Aug 25, 2017 6:51 pm

Thanks Greyhound, I did take note of your diagram and blasted the tube, inlet bore, and everything in sight to be honest, with carb cleaner. I used the little straw that comes with and it seemed to clear, cleaner was flowing thru anyway.

After seeing that new Mikuni's are about £400 and a total rebuild and restore of my Bings is £450 I think I'll be borrowing a sonic cleaner. I had one last year and had both carbs in it. I didn't strip them completely as I've never done it before, but I did manage to replace a fair few gaskets and O rings before reassembling. I thought that would be enough! Annoying because this current problem came on all of a sudden a few miles from home, and is causing such a headache. Thanks for your advise again.
1979 R80/7 also known as "Helga"

PhilO
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Re: Left pot miss fire back fire

Postby PhilO » Fri Aug 25, 2017 7:29 pm

You really must check out the compression for a burnt exhaust valve.
You could even swap the carbs from side to side to eliminate them as a trouble source.

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Jet
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Re: Left pot miss fire back fire

Postby Jet » Fri Aug 25, 2017 8:22 pm

Thanks PhilO, she has had new valves and valve guides about 4 years ago, done by the previous owner, so I kinda hoped that side of thinks would be OK. The old valves and valve guides were given to me with some other bits and bobs, so I know they were done. I have a friend with a compression tester though, I'll see if I can get hold of it.
1979 R80/7 also known as "Helga"

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Re: Left pot miss fire back fire

Postby windmill john » Fri Aug 25, 2017 9:02 pm

As philo says, just swap the carbs over as a quick test, that'll narrow your issue immediately.
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Galactic Greyhound
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Re: Left pot miss fire back fire

Postby Galactic Greyhound » Fri Aug 25, 2017 9:37 pm

As philo says, just swap the carbs over as a quick test, that'll narrow your issue immediately.

+1 That will save a lot of faffing about getting hold of a compression tester and definitely prove it into a faulty carb or not!
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" onclick="window.open(this.href);return false; - It works!


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