runs rich

[Guest davidb]

My v11 is running rich. It always had sooty plugs from the first 600 mile service to now with air box and exhaust mods. Any ideas? It does run real strong performance wise, but the gas milage is around 35 mpg. I live in the mountains and dont ride in city traffic much at all.

[Cliff]

Number of things effect the mixture

1) TPS setting/airbleed - are these set correctly?

2) Altitude - how high are you. Perhaps you're higher than the normal compensation allows for.

3) Oil temp, on the open road the bikes are over cooled. This might cause some residual choking. You can probably fake this sensor with a resistor.

[Guest davidb]

I checked the balance with my carb stic. I did not check the tps as it is still factory set. I didn't know that would cause it to run rich. I was under the impression that it just timed the intial fuel delivery and not the mixture/amount at given rpms. I will check the tps tommorow, thanks...

[Cliff]

The TPS/throttle is the primary mixture control. It is quite sensitive and has a big impact one your bike.

 

Too lean the bike a little rather than going thru a proper calibration it might be easier to note the current voltage and WITHOUT changing anything else on the bike adjusting the TPS to reduce the voltage by 5mv. If thats no good restore the setting or do a proper calibration.

[belfastguzzi]

I checked the Scura with a gas analyser and the CO is over 10% at idle. This must be miles too rich – it would certainly never pass an MOT like this.

 

I've just set-up the car's Weber carb and it runs perfectly, but I have never worked on any EFI stuff. Should I check / adjust the TPS as a first step? Can you confirm that 10% is far too rich for the Guzzi FI? Presumably it does not necessarily mean that it is running rich throughout the range, above idle?

[Cliff]

I think CO should be 3-4%

This could be an only at idle issue. If you get >35mpg its probably ok

The air bleed screw can also adjust the idle CO.

[Guest davidb]

The tps was fine. I found the air bleed screws way off. I reset them after backing out both Idle screws. I set them at 1/2 turn then adjusted the right one with my carb stick. (because the vacuum was lower on that side) Then I rebalanced the throttle bodies and set the idle. As a matter of fact, the idle screw (left side adjustment only) didnt need much adjustment to get to 1200 rpms. I left the right one backed way off. Now it is running properly and I am back up to about 38 mpg.

[belfastguzzi]

I think CO should be 3-4%

This could be an only at idle issue. If you get >35mpg its probably ok

The air bleed screw can also adjust the idle CO.

37508[/snapback]

 

Yes, I imagine that it may be only at idle. Plugs are ok after a decent run. But in relation to the 'MOT' test, which every vehicle has to do annualy, the CO is measured at idle. The bleed screws are probably the easy answer, if only for the period of the test. As db found that his were way off, it looks like this should be the first thing to try.

 

Question for UK people – I had been thinking that I wouldn't have to do the MOT until late 2006 as I bought the bike new in 2003, but is the first test date actually related to the year of manufacture? As it's a 2002 bike, it would then have to be tested next year. I suppose I better check this in the 'proper place', but what about you Baldini, for example. When do you reckon you have to get probed and prodded?

 

[belfastguzzi]

Looks like it's from year of manufacture. I can't see any reference to motorcycle emissions testing though. So maybe bike emissions aren't tested? Strange.

 

The limit for cars since 1992 is 0.3 & 0.5% CO, which is much lower than I expected, as I've been used to 3.5 /4.5% for older vehicles. If bikes are tested, presumably the V.11 CO would need to be down to 0.3 – 0.5% too.

 

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Carbon monoxide (CO) 0.5% at idle

 

 

Carbon monoxide (CO) 0.3% at fast idle