My bike smells! because no catalytic converter?

My friend was following me tonight for a good half hour he said my bike was smelling of gas to the point he was getting a headache. My bike runs really well, pulls hard and is a blast to ride. On the other hand, it is really hard to start. So, is it normal for these bike to stink or is my carb in need of attention?

 

Maybe your bike is running too rich (too much gas in the fuel mixture) or it's burning oil. It could be interesting to see the colour of your spark plugs electrodes.

 

I read here that the fuel mixture screw is only effective at idle/slow speeds but I was doing 70-100 kmh.
What makes my bike run rich at these speeds?

 

Yes. The idle fuel adjustment has a part in the fuel delivery at that speed. Especially if you are just in cruise (low throttle). The fuel level plays a big part as well. Not so much for the main jets, unless you are at WOT.

 

I forgot to mention....

A clogged air filter can cause an overly rich condition as well.

 

No matter what if it is caused by high fuel level in your float levels, clogged air filter or something else, the colour of your spark lpugs may tell a lot. PLease remove them, take pictures and post them here. It is easy, costs nothing and it is not time consuming.

 

Thank you all for your help! I will post the picture tomorrow.
PS I love my bike and want it to start and run well. I also own a Harley Superglide Custom but
this little bike is more fun to ride!

 

What's your bike by the way? year? model?

 

Your bike should never smell like in unburnt fuel going down the road. For sure your carbs have an issue. Clogged air filter, Float levels too high, wrong jets, maybe air jets in wrong place, possible leaking vacuum side of petcock drawing fuel in through vacuum line that goes to one of the carb manifolds. One other possible problem is and I have only seen this once. One or two of the main jets loose or fell out of the main nozzles. Too much fuel or rich mixtures can cause a lot of piston and cylinder wear because it washes the oil off of those parts. No oil extra heat and lots of wear not to mention gets in your oil also and that can effect the clutch and seals over time.

 

My bike is a 1982 750 seca. I had it cleaned by a local Yamaha dealer but I think all they did was to remove
rubber parts and dump it in the gunk. I'm gonna stop running it now and check the carb myself before I do real damage.

 

Here are pictures of my plugs after the foul smelling run, left to right.
Fuel mixture screw: 2 turns, 2.5, 2.5, 2.5 turns from closed, left to right.
Thank you for your help.

 

They look like you're running lean, exactly the opposite of what I expected, but I'm not the best plug reader on this site...the porcelain looks pink, that's weird.

 

your plugs are just a touch lean. your buddy just wants to lead sometimes, slow down and wait for him.
don't rip into the carbs because he says it smells like gas, if it runs good and the plugs look good, that's all that counts.
maybe you bought some stinky gas

 

ok, I buy that. My bike's only problem now is that it doesn't start 'sexy'. It takes a good 4-5 seconds to start
and then it revs really low ( below 1000) until I put it in gear and leave. Should I turn the screws to 3 turns or more?

 

Any adjustment on the mixture screws should be a lot more gradual than what you suggested. I'd try 1/8 of a turn out on each carb and see if there is any improvement, and keep monitoring the spark plug colour during the process.

 

If it gets sooty it's getting rich?

 

Exactly, if it's more black than brown it is too rich, ideal colour is tan, or coffee with milk, lol

 

Thanks. If you guys don't mind, I'm gonna go with one last problem I'm having.
Once during a given ride to work and back, the bike will suddenly drop the revs from 5k to 0 and back up, making my heart stop for a second!
Carb or electrical?

 

If it happened very suddenly, il really sounds like electrical to me. Could be lots of things, from an intermittant trouble with the kill switch to a bad connection in the fuse box.

 

Those plugs are close to perfect to me. Any adjustment of the pilot screws should be in increments about the width of a dime, in other words very slight. Recheck after about 40 miles and repeat adjustments until you think the plugs are perfect. I think the only way your friend is smelling gas from your bike is if you have a fuel leak.

 

Now I tend to think that your friend's car (or bike) has its own gas leak...

 

I would like to thank all who helped me. I did give 1/8 turn on all the mixture screws. As I mentioned, I was also having an issue
with cold starts being rough and low idling. Last night I tried turning and holding the throttle for 2 seconds before starting and to my surprise
it started instantly, rising and holding at 2k rpm on full enricher. That will be my new starting routine.

 

The cut out issue could be as simple as a dirty kickstand switch. If its dirty, the spring won't open the switch far enough, and vibration makes it contact

 

I'll check that tonight, thanks. ( I was gonna get new coils!)

 

When my bike smells of fuel it's because I didn't shut the enrichment lever off all the way.

 

I posted a picture of my spark plug and you commented that my bike was slightly lean. I then said that it had finally started well
after giving it 1/8 of a turn. The next day it was difficult to start and my plugs got totally fouled with soot and ran very erratically. I took off 1/4 turn
and cleaned the plugs but I'm afraid to try it again.
I am getting frustrated with this bike, it never runs the same twice. I'm looking at a brand new honda cb 1100 which looks surprisingly like my seca
but without the erratic performance.

 

1/4 turn is at least 3 adjustments.

 

If you bike stinks
STOP FARTING ON THE SEAT !

 

On the other hand, I rode a cb1100 and their real nice.