FLAT SPOT

[Tokalosh]

Please forgive me if there is a post for this but I could not find it in the search.

My Kat seems to have developed a flat spot around 3000 rmp in 3rd gear.
It is starting to tick me off a little and I would like to know what causes it and how to rectify it

Any help would be great

Tokalosh

[Court93kat]

Is it only in 3rd gear? Have you made any modifications to it lately?

Could just be time to run some fuel system cleaner through the carbs to loosen up some gunk. Or time to check the plugs for routine cleaning or replacing.

[md86]

JUST in 3rd gear ? Of course I have to point out ...

http://www.factorypro.com/tech/carbtune,CV,high_rpm_engines.html

[The CyberPoet]

You don't have an ignition advancer installed, do you?
I'm asking because the EU models already are advanced and installing one could really oddly effect your under 4k behavior in the first three or four gears.

TRY THIS: take out your air filter and vacuum out the inside [of the air filter itself] with the hose from a household vac. Doubt it will make a difference, but a physical blockage of some sort could just happen to effect the behavior at one specific pulse-frequency of the airbox.

Cheers,
=-= The CyberPoet

[Tokalosh]

Thanks for the addvice, yes I did install and ignition advancer a while back (bike is a gray import), then had the jets changed and dynod. There was no flat spot anywhere to be seen. Then out of the blue about 8 months ago I started to notice it in third and a little in forth. I think I noticed it more in third as I'm always seem to be in that sort of gear and rev band around town. It was not that noticable a first but now it seem to be getting worse or mybe just because I'm awear of it now. Funny enough I cant seem to feel it in any other gear.

I'll give the airbox pipes a good clean and see if it helps. Could it also be down to unbalenced carbs?

Thanks

Tokalosh

[The CyberPoet]

I'll give the airbox pipes a good clean and see if it helps. Could it also be down to unbalenced carbs?

It could be unbalanced carbs (in need of a carb sync), but it's not likely to be. Unbalanced in the sense that one has it's pilot screw out too far/in too far, or clogged passages are much more likely culprits. Or slide springs that are too strong.

Cheers,
=-= The CyberPoet

[trinc]

i would first ask why are you riding at 3k rpms in third gear ?

my twin pulls well from that low but an I-4 isn't going to have a lot of power down there. if the off idle circuit is fine in first & second then it's not going to change in 3rd.

if this problem is different then what it was maybe you have more drag on the bike compounding the problem - dragging brake, bad chain, slipping clutch etc. etc.

tim

[madkatana]

Might need a valve adjustment? Heard from several bike owners that when the katana acts like it never warms up, adjust the valves...my guess..

[Tokalosh]

Problem solved......

madkatana was right,it was my valves that needed adjusting.
I adjusted them for the first time yesterday after doing 22000km. Yup they were tight very tight.

After loosing the spanner down the cam chain well I was happy to see the end of it.
Thank f**ck for magnets! Not to mention the fact that I now walk like an old man with a crooked back.

The bike seems to be a lot smoother and when blipping the throttle it does not seem to over rev. The engine noise also seems to have subsided quite a lot. This is all good I hope.

Thanks once again for all the help.

Tokalosh

[GytRDunKat]

Holy dead post batman! Glad you got it goin right!

[grumpyoldgit]

Nice to see a completion of the issue, helps others when researching problems

[md86]

After loosing the spanner down the cam chain well I was happy to see the end of it.
Thank f**ck for magnets! Not to mention the fact that I now walk like an old man with a crooked back.

Been there , done that . 'Cept it was a socket I dropped . And I LOVE my telescoping magnet . Heating pads are nice , too .