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Discussion Starter #1
Well I just bought my first bike and it's likes to sputter in the upper gears. And in 5th gear it will hardly go 80 without the rpm hand jumping around. Any ideas what it could be? Thought I might have junk in the carb.? What's ur thoughts?
 

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Well I just bought my first bike
And you didn't realize this BEFORE you forked over the money ??
Alas, this might turn out to be a bad move and not a good first bike choice.

Could be simple or could be a major problem.

I'd first suggest draining the tank and float bowls and then fresh gas with a healthy dose of carb cleaner.

THEN.....other routine maintenance that you SHOULD HAVE insisted on being done before the sale.
Like plugs and valve check.

There always is a chance of something major......like bent valves, stuck rings or a blown head gasket.
Since the tach is jumping around, it could be that the ignition module is going bad......or something like a crank position sensor.

Let's hope not.

Life's lesson: NEVER buy a used vehicle that is not running right....IF you don't have the skills to fix it yourself.......and then only if it is REAL cheap.
 

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Discussion Starter #3
Didn't do it untill yesterday I bought it a few weeks ago and drained the gas put 97 in it changed the oil but haven't change air and fuel filters or plugs so is that what I should do?
 

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put 97 in it changed the oil but haven't change air and fuel filters or plugs so is that what I should do?
Yes.

And stop paying for octane that you don't need.
That actually can be part of the problem.

Did you also drain the float bowls ??
 

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And you didn't realize this BEFORE you forked over the money ??
Alas, this might turn out to be a bad move and not a good first bike choice.

Could be simple or could be a major problem.

I'd first suggest draining the tank and float bowls and then fresh gas with a healthy dose of carb cleaner.

THEN.....other routine maintenance that you SHOULD HAVE insisted on being done before the sale.
Like plugs and valve check.

There always is a chance of something major......like bent valves, stuck rings or a blown head gasket.
Since the tach is jumping around, it could be that the ignition module is going bad......or something like a crank position sensor.

Let's hope not.

Life's lesson: NEVER buy a used vehicle that is not running right....IF you don't have the skills to fix it yourself.......and then only if it is REAL cheap.
The real reason is most likely a K&N air filter, followed by limited fuel flow from a kinked fuel line or a petcock issue.

The chance of the engine top end being damaged is extremely rare. Those engines are pretty well bulletproof there.

The 98 models even fixed the issue with user abuse screwing up second gear, so that's not even a concern on the 98+ models.

99% of the time running issues for the Katana are simple, inexpensive, just slightly labor intensive if your doing all the work yourself. It's gets expensive when you take them to a shop for someone else to do.

Krey
 

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Do plugs and wires, if that doesnt help try spraying a ton of carb cleaner (few cans) through the intake as you rew the rpms up and down. Spray it at around the same rpms that it likes to sputter at as well

[Spam link removed.]
 

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Not really good advice....without a qualifier, that is.

Spraying anything into the intake at too high a rate tends to pass liquid right through to the cylinders where it can "wash" the oil off the rings. NOT good.

And maybe more important:
I can't take the time to edit the rest of your spammy posts to remove the links to an illegal activity so the other 8 will just be deleted.
Any further posting of illegal activity will result in you being BANNED.
 

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I think something gone hot, check your wires and air filter. Sometime it happen when dust come. I suggest you to check your bike with motor mechanic.

 

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As stated carbs probably need a good clean...even may be way out of sync You may find the fuel filter/s are badly clogged....sounds like fuel supply issues at higher rpm. Does this bike have an electric fuel pump....if so they need to supply at good regular pressure or problems occur. You might also need to check the tank venting system. One other thing make sure the plug caps are tight on the plugs and the cables....many become loose when the glue breaks down...vibration at the specific rpm may be allowing the lead/plug connection to break down....in fact with the tach doing the erratic sweep this could well be the problem...that or as ER said...the ignition module....or coil/s :bluethum:

Good luck
 
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