Triumphrat

FasTriumph · 09-16-2009, 05:25 PM

Over the past 4 weeks fuel economy has deteriorated from 40 to 30 mpg. The smell of gasoline has grown from ----> Is that fuel I smell? I don't think so. ---> Maybe I do smell fuel; nah, that's just exhaust. ---> Yep, I smell fuel.

First tank mpg was 42; after that I drove like a bat outta hell for 800 miles so it dropped to 38 mpg; got home; had several tanks around 40 mpg (only about 40 miles a day with city/hwy ratio of 50/50. Then the slow decline started. Became a little more sure of the fuel smell a few days ago. Last four tanks have gone from 35 to 33 to 30 to 30 mpg. I'm a gas mileage geek. I calculate it every time I fill any of my vehicles. OCD has its advantages.

The bike runs smooth. No performance problems. None. Really. It's as fast and as smooth as the day I got it.

I'm a rookie motorcyle mechanic with aptitude; I read all the files several months ago and will go there now to see what I can find. I'm committed to doing my own maintenance. I'll take my time and do what it takes.

Suggestions I have received so far are:
1. Check fuel hose that runs behind the carbs for cracks as mentioned in the Yahoo FAQ file. The cracks are usually nearest the heat source.
2. Leaking carb float valve in one of the carburetors. It is not shutting off inbound fuel flow when the bowl is full, so then it pukes out the overflow vent.

Any diagnostic guidance from you experienced forum members will be greatly appreciated.

What do y'all think?

btw, this is what I get for crowing "Trophy is Running Beautifully". Never tempt the gods of Triumph Motorcycle Maintenance...

narrowminded · 09-17-2009, 04:28 PM

Fuel lines
Petcock(check for oil contamination)