No smooth cruise mode?

[Banditclimax]

Hi guys and gals, having a slight jerky problem when in a steady cruising throttle mode, anywhere from 3 to 55 MPH.  I ride a 2005 B12 with about 2800 miles on it.  Did the 600 mile service, and not due for another until 4000, according to factory service recommendations. Wondering/hoping if it might be the air filter.  I only run 92 octane
Chevron Techron fuel, and add recommended amount of Marvel Mystery Oil mix.  I welcome any educated opinions.  Thanks, Banditclimax

[fake]

Don't know what you're talking about with the oil mix.  Our bikes are designed to run on 87 octane; maybe by running a higher octane, your bike is having problems with burning the higher octane.  I run 87 in mine and have never had this problem.

[Banditclimax]

Hello fake, thank you for your input.  You are the first person I've heard say that running a higher octane, may not be a good idea.  My intentions are to give my bike the best, so as to help avoid problems down the road.

     Anybody else agree that this may not be a good idea?

     I'll tell ya what fake, it's not going to hurt a thing if I  run 87 octane on my next fill up.  I won't put the oil additive either.  I'll let you know if there is any improvement or not.  Thanks again for your input, I appreciate it.  Banditclimax

[ttewejnodnarb]

Don't know what you're talking about with the oil mix.  Our bikes are designed to run on 87 octane; maybe by running a higher octane, your bike is having problems with burning the higher octane.  I run 87 in mine and have never had this problem.

+1

These engines run low compression ratios and don't benefit from higher octane...with that said I run 89

If you haven't done so already I would suggest checking the chain as well.  If your chain is loose or old it could contribute to the jerky feeling (especially at lower mph) when your niether on the throttle nor off the throttle but just running a "cruise" or "maintenance" throttle setting.

[stormi]

You are the first person I've heard say that running a higher octane, may not be a good idea.  My intentions are to give my bike the best, so as to help avoid problems down the road.

     Anybody else agree that this may not be a good idea?

+1 on the not a good idea.  The service manager at the dealer told me not to bother with the higher octane.  

Also, there is scientific reason for the bike to have more trouble lighting the gas if it's higher octane.  It has a higher flash point, which in essence requires the higher compression ratio to burn completely, and without it, it may leave deposits in the engine, making it worse to run higher octane than lower, and not only for the hit to the wallet.  (Geez I hope that made sense.  I have a cold right now, and trying to get that thought through the 8 cubic feet of cotton that seems to be stuffed in my head was a hell of a lot of work.)

Here are a couple of links (both links deal with cars, but the concept is the same and I didn't feel like looking further. :
http://www.automedia.com/High/Octane/Fuel/ccr20050501ok/1

And from:http://everything2.com/index.pl?node_id=807373

Contrary to what seems to be popular belief, using higher octane fuel in your car will NOT necessarily increase its performance. In fact, it will often decrease it and hurt your engine in the long run.

Here's why.

After fuel is injected into the intake tract and sucked into the cylinder, the intake valve closes and the piston moves up in the cylinder and compresses this charge of fuel and air. Here's where the octane rating comes in to play. If the engine compresses the fuel/air charge a lot (as in a sports car, which is typically 10:1 or more), the temperature will rise quite a bit. If you're using a low octane fuel, the chances that this temperature/pressure increase will spontaneously ignite the fuel charge are much greater. Since the mixture is supposed to be ignited by the spark plug, which does not fire until the piston reaches its highest position, the resulting explosion will be pushing AGAINST the piston. This phenomenon, called preignition or detonation, is what causes the "knock" or "ping" that people refer to.

The key difference between different fuels is that higher octane fuels are harder to ignite, and they generally burn cooler. That, in turn, lowers cylinder temperature and decreases the likelihood of preignition.

If you're talking about a high compression sports car engine, that's the reason for higher octane ratings. But if the engine in question is a typical sedan or van (or whatever else) engine, chances are it has relatively low compression. And if you're using high octane fuel in a low compression engine, not only will it be harder to ignite, but the chances are good that it won't burn as fully. Incomplete combustion will leave nasty carbon deposits in your engine. The thing about carbon deposits is that they retain heat much better than metal does and they decrease the combustion chamber area, thus gradually increasing the compression ratio. That means you've got a higher compression, higher temperature cylinder. And this, of course, will require higher octane fuel in order to prevent detonation.

So that's the deal. If you use high octane fuel in an low compression engine, you'll be ultimately increasing your octane requirement, and possibly causing carbon fouling of spark plugs, valves, and other important stuff.

All things considered, you'd be wise to just go with the recommendations in your owner's manual. If it says use "87 octane or higher", then use 87! This is one time that it pays to be cheap. If it says "91 or higher", then don't hesitate to use 91 or higher. Usually only 92 or 93 are for sale, though-- the available octane ratings vary depending where you live-- higher altitude areas have lower octane fuel due to the lower oxygen content of the air.

[smooth operator]

Sounds like it could be a little lean,I know they come lean for emissions. Perhaps raising the needles !/2 a knotch would help smooth it out. Being a new bike and w/o any mods from stock your jets should be fine, but ask your machanics opinion, or just try it yourself and it won't cost anything but a little time.(lean can cause a surging effect)

[Rocketjock]

I tried both in my new bike. With lugging the bike I picked up a hint of preignition so I switched back to high oct. I believe it's the best thing for the bike and at 25 bucks a tank I can't complain. Whoever said high octain is bad for an engine is just plain wrong. Revving the engine occasionally above 8000 (which is something I hope every Bandit owner does often) will definately clean out any carbon buildup. And the Bandit does have a fairly hefty compression ratio.

[Banditclimax]

Hello Brandon, thank you for your input.  You have a very good point about the chain.  I can guarantee that is not the problem.  I am a chain tension fanatic!  You can have the hottest raced-out engine between your legs, and it won't do  you squat, if your chain is too loose.  Thanks again, Paul
05 B12S

Don't know what you're talking about with the oil mix.  Our bikes are designed to run on 87 octane; maybe by running a higher octane, your bike is having problems with burning the higher octane.  I run 87 in mine and have never had this problem.

+1

These engines run low compression ratios and don't benefit from higher octane...with that said I run 89

If you haven't done so already I would suggest checking the chain as well.  If your chain is loose or old it could contribute to the jerky feeling (especially at lower mph) when your niether on the throttle nor off the throttle but just running a "cruise" or "maintenance" throttle setting.

[Banditclimax]

Hello Stormi, thank you for all of your great input on this subject.  BTW, I'm sorry to hear you have such a bad cold, but it did not hinder your response to me.  I will take all of your information into account.  I'm definately going to run a tank of 87 octane.  It can't hurt.  Thanks again, Paul

You are the first person I've heard

say that running a higher octane, may not be a good idea.  My intentions are to give my bike the best, so as to help avoid problems down the road.

     Anybody else agree that this may not be a good idea?

+1 on the not a good idea.  The service manager at the dealer told me not to bother with the higher octane.  

Also, there is scientific reason for the bike to have more trouble lighting the gas if it's higher octane.  It has a higher flash point, which in essence requires the higher compression ratio to burn completely, and without it, it may leave deposits in the engine, making it worse to run higher octane than lower, and not only for the hit to the wallet.  (Geez I hope that made sense.  I have a cold right now, and trying to get that thought through the 8 cubic feet of cotton that seems to be stuffed in my head was a hell of a lot of work.)

Here are a couple of links (both links deal with cars, but the concept is the same and I didn't feel like looking further. :
http://www.automedia.com/High/Octane/Fuel/ccr20050501ok/1

And from:http://everything2.com/index.pl?node_id=807373

Contrary to what seems to be popular belief, using higher octane fuel in your car will NOT necessarily increase its performance. In fact, it will often decrease it and hurt your engine in the long run.

Here's why.

After fuel is injected into the intake tract and sucked into the cylinder, the intake valve closes and the piston moves up in the cylinder and compresses this charge of fuel and air. Here's where the octane rating comes in to play. If the engine compresses the fuel/air charge a lot (as in a sports car, which is typically 10:1 or more), the temperature will rise quite a bit. If you're using a low octane fuel, the chances that this temperature/pressure increase will spontaneously ignite the fuel charge are much greater. Since the mixture is supposed to be ignited by the spark plug, which does not fire until the piston reaches its highest position, the resulting explosion will be pushing AGAINST the piston. This phenomenon, called preignition or detonation, is what causes the "knock" or "ping" that people refer to.

The key difference between different fuels is that higher octane fuels are harder to ignite, and they generally burn cooler. That, in turn, lowers cylinder temperature and decreases the likelihood of preignition.

If you're talking about a high compression sports car engine, that's the reason for higher octane ratings. But if the engine in question is a typical sedan or van (or whatever else) engine, chances are it has relatively low compression. And if you're using high octane fuel in a low compression engine, not only will it be harder to ignite, but the chances are good that it won't burn as fully. Incomplete combustion will leave nasty carbon deposits in your engine. The thing about carbon deposits is that they retain heat much better than metal does and they decrease the combustion chamber area, thus gradually increasing the compression ratio. That means you've got a higher compression, higher temperature cylinder. And this, of course, will require higher octane fuel in order to prevent detonation.

So that's the deal. If you use high octane fuel in an low compression engine, you'll be ultimately increasing your octane requirement, and possibly causing carbon fouling of spark plugs, valves, and other important stuff.

All things considered, you'd be wise to just go with the recommendations in your owner's manual. If it says use "87 octane or higher", then use 87! This is one time that it pays to be cheap. If it says "91 or higher", then don't hesitate to use 91 or higher. Usually only 92 or 93 are for sale, though-- the available octane ratings vary depending where you live-- higher altitude areas have lower octane fuel due to the lower oxygen content of the air.

[Banditclimax]

Hello Smooth Operator, thank you for your input.  You may be right about it running lean.  My exhaust does smell a little rich.  I just though it was from burning the higher octane fuel.  Thanks again, Paul

Sounds like it could be a little lean,I know they come lean for emissions. Perhaps raising the needles !/2 a knotch would help smooth it out. Being a new bike and w/o any mods from stock your jets should be fine, but ask your machanics opinion, or just try it yourself and it won't cost anything but a little time.(lean can cause a surging effect)

[Banditclimax]

I tried both in my new bike. With lugging the bike I picked up a hint of preignition so I switched back to high oct. I believe it's the best thing for the bike and at 25 bucks a tank I can't complain. Whoever said high octain is bad for an engine is just plain wrong. Revving the engine occasionally above 8000 (which is something I hope every Bandit owner does often) will definately clean out any carbon buildup. And the Bandit does have a fairly hefty compression ratio.

Hello Rockejock, thank you for your input.  I have gotten a lot of great responses to my problem, as you can see.  I have not done the above 8000 RPM revving though.  sounds like an easy, good idea.   Thanks again, Paul

05 B12S

[fake]

You can always run some carb cleaner through the tank.  I run STP about every 6 months.

[CWO4GUNNER]

The premium fuel is defiantly not the problem. Its true that the B12 compression ration was designed to handle regular octane fuel (just barley) for the sake of economics, but the additives in premium fuel (more expensive) only insures a more stable burn for no pre-ignition under high demands. I have run premium in my 2005 B12 since day one (now 2500 miles) with of course, only good effects.
   The 10,000 dollar question is who did your servicing, what did they do, and did you see them do it. My B12 was starting to run with a few qwerks when I did my servicing the most significant improvement occurred as a result of synchronizing the carbs. Like a new team of horses during break in the linkage between them changeand of course it starts to serge. If I were you with 2800 miles I would do the following if you haven’t done so already and I would do it myself because at a dealership there is a 99% chance that you bike just sat there and killed time waiting for you to pick it up and pay the cash, or worse a vacume hose was pulled off and taped for future servicing business.
If you haven’t already done so. Change and gap the plugs, change the oil, change the air filter, synchronize the carburetors (a must), oh feel free to run premium.

[Banditclimax]

The premium fuel is defiantly not the problem. Its true that the B12 compression ration was designed to handle regular octane fuel (just barley) for the sake of economics, but the additives in premium fuel (more expensive) only insures a more stable burn for no pre-ignition under high demands. I have run premium in my 2005 B12 since day one (now 2500 miles) with of course, only good effects.
   The 10,000 dollar question is who did your servicing, what did they do, and did you see them do it. My B12 was starting to run with a few qwerks when I did my servicing the most significant improvement occurred as a result of synchronizing the carbs. Like a new team of horses during break in the linkage between them changeand of course it starts to serge. If I were you with 2800 miles I would do the following if you haven’t done so already and I would do it myself because at a dealership there is a 99% chance that you bike just sat there and killed time waiting for you to pick it up and pay the cash, or worse a vacume hose was pulled off and taped for future servicing business.
If you haven’t already done so. Change and gap the plugs, change the oil, change the air filter, synchronize the carburetors (a must), oh feel free to run premium.

Hello CWO4GUNNER, I like your advice.  I too wondered if anything had been done to my bike after, getting it back from service.   No I did not stand there and watch the work being done, and I really wish I had.   1 tune-up coming up!

[Banditclimax]

You can always run some carb cleaner through the tank.  I run STP about every 6 months.

Thanks fake, I'll try that too.