R80 g/s Lean running on right

Airhead_Martin · Apr 12, 2017

Hi, I'm struggling to find the cause of lean running on right hand side. I've rebuilt the carbs with kits from Motorworks, checked and rechecked settings problem persists any ideas. I'm at the pissed off stage so actual human contact would perhaps be more effective, south Manchester. Thanks Martin

scooter paul · Apr 12, 2017

My first thought is 'have you an air leak'?
Paul.

Deleted account 211025001 · Apr 12, 2017

I'm currently working through exactly the same on my Guzzi.

You don't say what you have and haven't checked so;

First check for air leaks on the inlet side & outlet/exhaust and that everything is done up nice and tight.

Then check valve clearances and ignition timing.

Once all the above is good then check your carbs are set up correctly and not worn (which you say you have done).

How do you know it's running weak? Exhaust bluing (if chrome/stainless)? Plug colour? Popping/missing when cold and first off choke?

Andres

Kenny · Apr 12, 2017

As above...also start with mixture screws both 1.5 turns out ( screwing out enriches mixture for 1st third of throttle openings etc )

mikeyboy · Apr 12, 2017

Compression check,
No point messing with anything till you know the suck,squeeze,bang,blow is good

Airhead_Martin · Apr 12, 2017

Thanks guys, will go through the items raised. Condition was confirmed by plug comparison. I will concentrate on inlet/outlet leaks first.

solidstate100 · Apr 13, 2017

airheadmartin said:
I will concentrate on inlet/outlet leaks first.

I would concentrate on what Mikeyboy said first, then go from there - all else is pointless unless you know the compressions are good. Also is the engine worn? It is not uncommon for the left hand cylinder to show a darker plug colour (making you think the right hand cylinder with it lighter colour is running lean) - this is due to the oil breather tending to vent into the left cylinder during running, and oil seepeage directly into the left inlet tract from the airbox if the bike is left on its side stand.

DrFarkoff · Apr 13, 2017

airheadmartin said:
Thanks guys, will go through the items raised. Condition was confirmed by plug comparison. I will concentrate on inlet/outlet leaks first.

Compression test first! Don't fanny around until you know the compression is good

I had one here to fix that was "running fine" but a little hard to start "Allegedly!!!"

I had a quick look and after fannying around for about 5 minutes, I stuck the compression tool on it only to find it had 20 psi on right side and it was a cracked valve

Its the best line of attack on any bike that has running problems Start at compression, then fuel, then coil, diaphragms etc

R80 g/s Lean running on right

Airhead_Martin

Registered user

scooter paul

Well-known member

Deleted account 211025001

Registered user

Kenny

Trustworthy Scouser AND

mikeyboy

Well-known member

Airhead_Martin

Registered user

solidstate100

Well-known member

DrFarkoff

Grumpy Ole Git!!!

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