WTF - 10 miles per gallon??!!

[k_lundquist]

Please help - I'm really starting to hate my Bandit.

I'm new to this forum looks to be a great site.  I tried searching but unfortunately I could not find my problem.  So here goes:

My bike is a 1997 Bandit 600S w/14,000 miles on it.  It looks great and WHEN it runs its a blast.  Unfortunately its been in repair more than on the road.  I bought this bike 3 months ago figuring it would be a great starter bike.  The guy that owned it before me *seemed* to have taken decent car of it.  Had records and did periodic maintainance.  Though he admitted it did sit for a bit.  It ran, but somewhat rough.  Really no power in low RPMs - pulled hard over 3k - some white smoke.

No prob I figure a good carb cleaning should fix it right up.  I know a local motorcycle shade tree mechanic through a friend.  I take it to him.  Sure enough the carbs need adjusting and were pretty varnished up.  He cleans it out, bike runs great.

Or so I thought...  I take it home to find the next morning its leaking gas AND it takes a whole lot to turn over.  I take it back to my guy.  Bad float needles.  Apparently in the cleaning he had to take the old ones out and they were so vanished up that w/o the gunk they didn't sit right.  New needles and the bike runs great.

Or AGAIN so I thought...  It ran awesome for 3 weeks.  I was getting about 250+ miles per tank.  Then all of a sudden i noticed I was refilling it more.  Today alone in 40 miles it went through 6 gallons of gas!!!!  Its not leaking fuel this time.  Now white smoke comes out of the exhaust over about 4k RPMs.  I'm guessing the bike is super-rich and all my unspent fuel is going right out the tail pipe.  I called up my guy.  He thinks its the needles.

I'm hoping you guys can help me.  What do you think the problem could be?  Should I even bother going to this guy, or just bend over and take it at the dealer?  If so - how much $$$ would I be looking at?

Thanks!  And sorry for the long posting...

[pmackie]

Still sounds like a float needle and/or float height problem, and yes, you are likely pushing raw gas through the engine.

At this point, I would want to do the following:
1. Make sure the fuel tank valve (petcock) is not leaking, ie is OFF when there is no vacuum.
2. Make sure the oil level is not increasing with fuel entering the crankcase.
3. Make sure the float needle valves are not leaking/shut off positively.
4. Make sure the float height is set correctly.

[k_lundquist]

Yay! A reply! :)

Glad to hear its probably the needles.  Poking around on the forum and the net in general had me worried it could be a head gasket or another serious issue.

Carbs really are a PITA.

Also thanks for the suggestion on the PetCock - I think its OK though.

[k_lundquist]

Update:

In case anyone is interested... looks like its my floats.  Though my mechanic should have it figured out after pulling the carb soon.

As psmackie mentioned raw gas was being pulled into the engine, mixing with oil, and generally flooding my bike.

[mademiriam]

thanks for the update, the floats did seem to make sense but I also wondered why he hadn't noticed it... hope it's all fixed up now!

[k_lundquist]

Pulled the carbs and though it was the float needle in #1 it was caused from a broken jet.

Apparently the previous owner had messed around with the carbs.  Initially when I bought the bike I knew the carbs needed a good cleaning – but someone had really mucked them up.

Not only were they pretty varnished up but they were completely out of sync and carb #1 had a broken jet head.  My mechanic pointed this out originally, but suggested against addressing it as most of the jet was still in there and functioning.

Well after the bike actually getting some usage that jet vibrated out and lodged itself into the needle causing a stream of fuel to flood the crankcase.

Thankfully it’s an $8 part and apparently an easy repair.  The part’s still on order, hopefully arriving soon.  Unfortunately that small part cost an additional oil change and new plugs.

But I look at the brightside – all this cleaned the engine out pretty good.

[k_lundquist]

Well *knock on wood* looks like I'm back on the road and the bike is running good again.