Poor Fuel Economy

[Gibbo_3k]

Hi,

I'm only getting about 40Miles to the gallon on my CB1.  Recently I spoke to someone who said the fact it had been restricted
would be the cause.

My license allows me to ride a bike up to 33bhp, so anything bigger has to have a restrictor fitted to the carbs.
Has anyone else had this trouble or have any suggestion as to what I could do about it?

I've only had the bike two months ago  and it has about 10,000 miles on the clock.

-Gibbo

[psubrock]

The bike makes 50ish hp if you jet it right, those restricters are keeping you legal.
I wouldn't mess with them, from what I gather the laws on your side of the pond are pretty strict about that stuff.

[Gibbo_3k]

I have to be honest, the idea of taking them off doesn't appeal to me at all, however
most of the people i've spoken to who had restrictors, said they took e'm off them off 

Is it posible that they have been fitted badly and are casing poor fuel economy?

[marty]

40mpg sounds pretty good to me... i will only get more than that on long highways stints *shrug*

[mrbones]

If I ride only on the highway (75mph), I have to switch to the reserve at 80 miles. This high revving engine with no wind protection doesn't fair too well for good highway mileage.

[Gibbo_3k]

40mp/g sounds good?

I would expect that from a car, not a bike!
Damn, im really starting to miss my GS125 

I have to switch to reserve at 68 miles. For some reason my tank is 8 Litres + 2 for reserve.  The manual says it should 11 litres (I think)

-Ian

[Rusty]

Run a magnet around the outside of your tank. I think that your tank is dented, and repaired with "bondo". The magnet will not stick to the the repaired area. The dent is limiting your capacity. Does your tank look like it has been repainted?

[psubrock]

I get 40-45mpg riding like a maniac, I have seen as good as 52mpg taking it easy when I have the little lady on the back 

[Gibbo_3k]

Somone said to me recently that I could be suffering from a low compression.
I'm not to sure what that is but I think its something to do the pistons loosing power through the top.

[mechdziner714]

You can do a compression check, remove one plug at a time, screw in comp gage & carnk over. With only 10K on the clock I seriouly doubt thats your problem. 40MPG depending on how you ride is about right. Is there a power problem?

[Rusty]

To do a compression check, you need to remove all the plugs. With all the plugs removed, the starter now can spin the engine fast enough to get a good reading. When doing the compression check, write down your readings. This way you can see which cylinders are low, one by it's self, or as a group. You should do 2 tests. The first test dry and the 2nd wet. The first test is like you would normally do. The 2nd is when you add 10cc's of oil to the cylinder, spin the engine with the starter, then install the compression tester and test. Do one cylinder at a time with the wet test. With the dry test, it gives you a base line. With the wet test, you can see if the rings or valves are bad. After the wet test, if the compression goings up, chances are the rings are not sealing. If the compression stays the same, it could be the valves.

Sorry if the above reads long. It's a carry over from the morons I work with.

And did you chech your tank with a magnet lately to check for hidden dents?