Hi,

I have a old WeedEater lawn tractor with a 42" deck and a 16 hp Briggs & Stratton Twin II engine, it starts easy and i think it runs ok (have not seen other with this particular engine, so i am unsure of how it is supposed to run/sound)

But it seems to have a very high fuel consumption, and it does smoke a little and it smells alot like fuel, it does not smell like burning oil. 

I do not have experience with these engines, they are quite rare here where i am from. So i hoped i could get some assistance on where to look for trouble shooting for a high fuel consumption on these engines.

Best regards Mads

Can you post a model #, I don't recognize what a twin II engine exactly is.
 
In any event, how is the oil level?  Is it low, is it high and smell like fuel dilution?
 
Whitish smoke is oil, black smoke is fuel..
 
 
 
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Hi, thanks for your reply.


Engine specs:
Model: 402707
Type:127001
Code: 9412095A

The oil level is a bit high, but does not smell like fuel diluted. But i will drain the oil, and refill with nice clean oil and make a note about the level. 

I don't think it "smokes" the exhaust just smells like its burning alot of fuel ... So i was wondering maybe these carbs are known to have any issues. I have never seen this carb and engine before, so not too familiar with it. 

It start right away and idles decent, it also revs fine. But it have a really high fuel consumption ... I know it is a old contruction with a flat heads and so on ... But it seems excessive still ... To me at least.

Ok, here's your engine (an opposed twin):
 
https://www.jackssmallengines.com/jacks-parts-lookup/manufacturer/briggs-stratton/briggs-stratton-engine/400000-699999-series/402700-to-402799/402707-1212-01/air-cleaner-group-fuel-hoses
 
How long have you owned this machine? 
If it's "new" to you, it's very possible someone's been in the carb and dinked with it.
Could have left a gasket out, a worn gasket, "opened up" a jet, etc. 
 
If need be, print the carb parts diagram out and remove your carb.  Start comparing your assembly
to the diagram and any abnormalities.. 
 
You could have a leaky carb needle / seat as well. 
 
Do you have a fuel pump?  If so, check for any leakage from the pulse hose into the crankcase. 
 
You may also want to just un-bolt the carb from the manifold, line hooked up and fuel turned on.
Then monitor for any leakage.
 
 
 
 

It is new to me. It is certainly possible somebody have been fiddeling with it. 

It seems that the carb have a built in fuel pump by the looks of it.

Ok,  again I'd partially remove the carb and check for leaks.
 
I suspect something is amiss inside the carb.  Could be a bad gasket, o-ring, lack of parts,
modified parts, etc...
 
 
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