Lousy gas mileage, and now...

R

Ravenshurst

New Member
Hi everyone...So I have only put about 100 or so miles on my engine, and I have never gotten anywhere close to the advertised mileage. I am only getting about 60 miles per gallon. The engine has been running fine, since I have been really careful about breaking it in. Never more than 30 miles an hour, never more than 30 minutes at a time, with a minimum of 30 minutes rest between runs. I have a 44T sprocket. The carb has not been adjusted, re-jetted, touched since leaving the factory. I have not yet installed the fenders, luggage rack or head light, so the bike is basically stripped down, no heavier than any other bike. I weigh about 135. Sorry this is so long, but I am trying to list all of the info I can think of...Tonight on the way home the engine was running good, started pulling really strong, and I thought maybe this was a sign that it was breaking in. When I pulled up to a light & pulled the clutch in, the engine red-lined. Well, I don't really have a tach, & wouldn't know what red-line is any way, but it wound all the way up. I choked it all the way and the engine slowed down to about normal, but it was idling really rough and the full choke didn't kill it. I could really use some help!!! Again, I am sorry this is so long. Thanks.

Ride Safe!

Gonzo
 
Howdy Raven. Long is good. The more info the better. The China girls never get the 150 MPGs advertised, well, none of mine ever got more then 133 and I weigh 165/70 LBS and live in flat area. 60 MPG during break in is about right in my experience and would not worry. Not sure about the over revving, but some one will. If the throttle cable is adjusted correctly (as it had been running well) and freely moving, might just be a matter of adjusting the mixer screw. Just some thoughts. I am in no way an expert, just a backyard builder.
 
I have never gotten more the 120 mpg, I have gotten as low as 50 mpg and still have never figured out why such a huge difference from one day to the next ridding in the same type of terrain.

30mph 44t sprocket? I have 44t and 30mph for me is max RPM. That might explain your low fuel millage.

Are you sure your throttle cable is not sticking? Maybe the slide in the carb could be sticking also. Shoot, my mind has gone blank....... you know the part that screws onto the carb at the top that the throttle cable goes through? Sometimes I have found out if you over tighten it, it will not allow the slide in the carb to snap back when you lift off the throttle.

I would also check for any vacuum leaks (air leaks as some like to call it, but I don't know why, no air leaks out)
 
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.trkBefore I modded mine to h#ll :) i was getting 160mpg but i rode it at a slow speed (~15mph) and coasted down hills. Now with my mods and shifter kit im gettin about 130+mpg at ~30mph. When my motor was stock and i revved it that quick, i didnt get that good of mileage and never revved it like that till it was broken in. I thought my directions said for break in not to exceed 15mph for 15 min for the first couple rides then not to exceed 15mph until 2 full tanks of 16:1. As for the having to use the choke to keep it runnin, Im sure you have an air leak somewhere... carb-manifold connection, manifold-cyl connection, cyl-head connection, break out the soapy water and spray at these locations to see if you can locate the leak... (there will be a change in rpm) Good Luck -Justin .trk
 
its a airleak,seal where throttle cable screws in on carb and where cable goes threw hole too. use gasket maker or teflon tape. seal the carb to intake.
after warm up , when you choke it, it should stop or almost stop.
plus check your throttle cable,they like to stick a lot.
 
How about 36T sprocket , carrying saddlebags full of gear and extra fuel. I weigh in at 188 lbs. 85 miles one way 1/2 gallon with a little fuel left in tank!!! round trip 170 miles to the gallon!!!! HoooRaaahh
 
With a 56 tooth sprocket 50cc iam getting 150 mpg --of course iam 215 lbs but it is a canadian gallon one fifth larger-- i also carry gear because i travel mostly back gravel roads--tuned pipe big carb
 

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I have a 40T rear sprocket 80cc, I weigh 185 lbs and without getting much over 25mph I only get about 50 to 60 mpg. Never really believed the mpg claims and although its only a fraction of mileage I feel fortunate that it's 50 to 60 mpg. The higher the rpms the less likely you are to attain any real mpg and if your a large man even less.
 
today i checked my mileage and gas records and im getting 166mpg(miles per gallon).
i think that would be about 83 miles a tank.
i travel anywhere from 20-32mph. my oil/gas was 16:1 and now 20:1, i think.
i have a 48cc dualstart starfire gt2 grubee 44t sprocket 26" mountain bike (im 120lbs)
engine is stock from gasbike.net and bike is used with slighty warped wheel.
i have a black cat muff on it too.i bet i get even better mileage if i had a new cruiser.
 
when choke lever is all the way down push in clutch and adjust the idle screw
i also had to put some silicon glue around engine to carb intake pipe.
had a tiny airleak around the carb clamp
 
Robin-- Just saw your post about the Canadian gallon.I'm in BC [White Rock] and in this part of British Columbia we've been using metric measure since the mid 70s.
The old gallon is gone.It's now 4 Liters=3.78 US gal.It's $4.00 Canadian.
 
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