EC 300 Gas Guzzler- Ideas??

[GasMCAndy]

My buddy rides an 05 EC250 now with a 300 cylinder and head. RB Squishband mod. Sure bumped up the power nicely but this bike now drinks fuel FAST! Standard 38mm Keihin 42/CEK/188 today in the cold. 2_1/2 gallons sucked down in just over an hour ride time! Bike runs good -a normal smoker to me.

I ride an 04 MC250 which uses half that and I have to run 45/DEK/195 in the same carb. Our other buddy rides his CR 500 smoker using half this amount of fuel too.

No residual fuel in the 300 crankcase after our ride today. This bike has been a 300 for a while now and always burns way to much gas. ANY IDEAS?? We need a better solution than staying within three miles of a gas can at all times.

Thanks-

-Andy

 

[Jakobi]

Float level good? Not spilling or splashing out along the trail?

 

[trialsridr]

Float level good? Not spilling or splashing out along the trail?

+1. That would be my guess float/ needle/ seat . Fuel running out of the overflow tubes while riding

 

[GasMCAndy]

Hey - theres one worth checking. We'll lean her over and see. Maybe a quick ride with a catch bottle.

Any other ideas if not there anyone?

 

[Jakobi]

I'm pretty sure the CEK/CCK needles are quite thirsty in the grand scheme of things. People have found better fuel efficiency using other needles but thats opening a whole other can of worms.

If the bike isn't running crazy rich, and is still getting horrible fuel consumption I'd be looking for fuel loss elsewhere.

 

[swazi_matt]

Hey - theres one worth checking. We'll lean her over and see. Maybe a quick ride with a catch bottle.

Any other ideas if not there anyone?

I would think your only 2 reasons are float level or rich jetting ... what sort of mileage are you getting on a tank on normal trail riding?

 

[wasp4banger]

I'm pretty sure the CEK/CCK needles are quite thirsty in the grand scheme of things. People have found better fuel efficiency using other needles but thats opening a whole other can of worms.

If the bike isn't running crazy rich, and is still getting horrible fuel consumption I'd be looking for fuel loss elsewhere.

I run my 06 ec300 on a 36mm carb (standard I think) with 42/CCK/178 jetting, it does a good 3 hours on a full tank. The 188 looks on the rich side, there are other threads here on jetting.

To use that much fuel though, its likely to be the overflowing carb

 

[FFRDave]

39mm carb, with plate on my 300

One of my tubes has been crushed in the shock spring, but the bike does run strong. As soon as I can, (probably Friday), I will check the carb for overflow, and any fluid in the float.
Thanks for all of your help with this GasMCandy.

 

[Jakobi]

Just turn the gas on with the bike in the shed. Clean floor beneath you. Bounce the bike up and down. Lean it over to the left, lean it to the right. Pull the front brake and rock it back and forward. Have a look under the bike. Any fuel on the ground?

Ideally the carb should overflow when the bike reaches 45 degrees to each side. Not before, not after.

 

[rod]

I found poor economy with the CEK in my 38mm asII but liked its broad smooth performance, i've had only one ride with a CEL, but fuel economy has improved considerabaly to the point it was better than some of the 4 strokes with us on the day, including an almost new husky te 449 with FI. All i did was set the cel @ 3 as opposed to cek @ 2, and had to richen AS slighty, pj is 40, mj is 178. I am in Australia which is a bit warmer then your location, about 25 celcius on the day i described. I found starting and idling very good but so to was the cek, i haven't been out since on it due to busting a rib,but i had 5-6 hours on it before that happened, so i'll be staying with the CEL for the time being and fine tuning from there.

Your 188 mj sounds way rich, maybe start by leaning that off 1st.

FWIW, i previously had an '05 ec 300 with the asI carb and i really liked the performance and fuel economy i got with an N3EG needle, once again this is in my location of OZ where 15-20 degrees celcius is the coldest it gets whilst out riding, and roughly sea level.

As Jake has stated, if you wan't to start delving into jetting, then check out jetting/intake section, it will do your head in.
I've probably started the ball rolling due to this post, but if your up for it there is some great info in there, you just got to decipher whats relevent for you and your bike.

PS: I've re-read the original post in a more sober light, 2 1/2 gallons(approx 11 litres) in just over an hour is ridiculous, CEK is not that bad. Got to be losing fuel somewhere as others have stated.