Bandit Alley
GENERAL MOTORCYCLE FORUMS => GENERAL MECHANICAL & TECHNICAL => Topic started by: Tapout on April 13, 2007, 03:15:26 PM
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Hello everybody, just purchases a 99 b12 a couple weeks ago, and recently found this forum. Unfortunately, it has been raining and snowing since I bought the bike, so no chance to really ride. It is sunny and 50 today and suppose to be about 60 by the weekend...woohooo. I have always been just a rider only, never worked on the bikes myself. I had 2 CBR 600s back in the early 90's, and to the point in my life I want to learn to wrench on my own bike, as well as ride in a little more comfort...hence the purchase of the Bandit.
So, here come a couple questions.
1- What type of mileage should a stock 99 B12 get? As stated above I have not riden the bike enough to determine what it is getting. I did notice that the fuel gauge did seem to drop down quite fast on the ride home.
2- Speed seemed to be off, so I took GPS out with me when I got home. The bikes indicated speed was 5 mph less than GPS indicated speed. Am I correct in thinking that gearing and/or tire diameter affects indicated speed?
3- The owners manual states that final reduction ratio is 45/15...is that referring to the sprocket teeth? The previous owner put on a new sprocket and chain...rear sprocket is 46 tooth, and not sure on the front sprocket. The tires are also new 180/55zr17 rear, and 120/70zr17 front, which is what the owners manual indicated.
4- I also noticed that at slow speed/rpm in first gear, it "surges", but smooths out once rpms increase. Seems really smooth and great power once rpms up in first gear, and seems fine other 4 gears...any ideas?
Oh, the bike also has a Yoshirmura RS3 and unsure of jet kit. I did read a post about identifying jet alteration on carbs. I looked under carbs and it appears as if the plugs are gone, and can see adjustment screws. I also read the post about TPS adjustment. Any recommendations on what to do first to smooth out the "surging"?
Any advise or opinions would be greatly appreciated. Sorry for the long post...I'm just getting excited to get out and ride now that the weather is starting to cooperate. Also, I did order the Haynes manual, so hopefully I wont be posting such long questions in the future. Thanks again in advance. - Kel
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1. Totally stock (no jet kit/slip-on even) should get ~40mpg +/- a few mpg for riding conditions and production variation. WITH a jet kit & slip-on expect a couple mpg less than stock to up to -10 if the jet kit is Dynojet's.
2. You are correct in assuming tire diameter effects the speedo. With you bike, what we call here a 1G, the speedo will be affected by the front tire, since that's where the speedo drive is. The newer bikes have electronic speedos and get their signal from the countershaft sprocket, so rear tire and gearing changes will affect them. However, on ALL Bandits, the speedos are optimistic. More than being "5 mph off" they are off by a percentage. Actual percentages seem to vary a little, but typically are in the 10% range. It's not uncommon for the electronic speedos to have extrapolated error, in other words, the percentage off gets greater the faster you go.
3. Yes, 45/15 is the tooth count on the rear/front sprockets from the factory.
4. Surging usually indicates excessive lean condition.
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Welcome and congratulations on becoming a Bandit owner.The 1st gen. Bandits do not have a TPS, so you don't have to worry about it.
+1 on what Red01 said. :bigok:
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LOL - I was concentrating so hard on answering the items he numbered, I forgot to mention his lack of TPS... even though I was thinking about it when I read his post.
:duh:
Thanks for catching that and clearing it up!
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Thanks guys for the quick replies and education on my bike. If all goes as planned, I will have her out this weekend. Interested to see what type of mileage she gets. I will be using it as commuter a couple times a week (65 miles each way), and group rides on the weekend.
As for the sprockets...since mine has a 46 rather than the stock 45, what should I expect to find for the front sprocket? What would the purpose be for the previous owner to put on the 46 rather than the 45?
Also, any recommendations on literature for carb tuning? I would like to see if I can work out the possible lean condition, and see if I can get the "surging" to stop. Is their a way to tell what jet kit they put in bike?
Thanks again, and I'm having a blast reading all the posts. Just trying to take it all in.
Kel
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A larger rear sprocket lowers the gearing slightly (though in this case only 1%, if the front sprocket is stock).
Lower gearing is usually done to increase acceleration at the expense of top speed, but the 1% change will not be very noticable.
I ended up with a 46 rear sprocket as Regina sells a KIT that includes the Chain and sprockets, but it only comes as a 46. But remember, mine is a 2nd Gen 600.
For your surging, I would first try turning the air screws OUT 1/2 turn, but you should determine how far out they are now. IE: carefully turn them IN, counting how many turns until they bottom out, then turn them OUT. 3 or 3-1/2 turns seems to be a good starting point.
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If you're going to turn the air screws in, make sure you are really, really, gentle. So gentle that you can use a small screwdriver and two fingers to turn it. You don't want to damage the tip of that screw. I'd use a pencil and mark the screw and the side of the carb too so you can try to count the turns a bit more accurately.
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Take a look at your vacuum lines and check that the clamps on the front of the carbs (manifolds) are tight. Vacuum leaks will make it run lean as well.
You may want to run some Tecron or Sea Foam through it if its been sitting all winter.
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Thanks for the additional advice....you guys are awesome. :thanks: