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Hey there. I bought a 97 katana off someone knowing that it needed a little work. stripped down a bunch of it. cleaned the carb and sparks, new battery, refreshed K&N. I DID get the bike started. took it for a small jaunt yesterday... but the bike is just running rough. Does NOT sound like an inline bike. SOME issues idling. throttle delays as well as unexpected "take offs". Ive been advised to do carb syncing... but while doing a little more research, I was told It might be valve issue too? The bike supposedly ran good before it sat for a couple years. Just looking for some incite on what my next best move is. I was also wondering if valve adjustment would screw up synced carbs? and while im thinking of it... I cleaned the carbs off of "generic info". Is there anything specific with the katana carbs that you need to be accounted for? thanx guys.
 

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Did you actually take the carbs apart and meticulously clean every little part and inner passage? Or did you just spray some carb cleaner on them to make them LOOK clean? Gas turns to varnish as it gets old, and it leaves a nasty coating when it dries, so the little inner passages and parts get pretty boogered up and no amount of spray on the outside or down the throat of them will help.
Was there a K&N filter on it when you bought it, or is that something you added in place of the stock one? The intake system (filter) needs to match the way the carbs are jetted, so if it was set up for a stock filter when you bought it your first step is to put a stock one back on it.
Also, have you checked for good spark at all four cylinders? You would not be the first to have a loose plug wire or some other ignition problem following a plug removal/ replacement.

A valve adjustment problem would cause all kinds of funny noises, but not necessarily the problems you are having. Unless the carbs are ridiculously out of sync, problems in that area usually show up at higher RPM and do not affect idle- they make the bike shake like crazy when you roll the throttle on because the cylinders are fighting each other by trying to run at different speeds.
 

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I bought a 97 katana off someone knowing that it needed a little work.
And SOOOOO often that turns out to be a bigger mistake than one EVER imagines.

It is impossible to give more than guesses without being there but some basics apply:
Put in new plugs, gapped for that engine.
Put a stock air filter back on it......unless the previous owner changed the jets.

Put some carb cleaner IN the gas and run it a few times over a couple of days; Berrymans B12 Chemtool at a double dose.

Choke it to start and leave the choke pratially on until it warms up good. This might be several LONG minutes.
It is normal for carb'ed bikes to not run good until warmed up.

Forget valves for the moment.
Carb sync is needed ONLY if you took the throttle linkage apart during the cleaning.

I hope you got it for a steal. A shop visit might be required before you are done.
 

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Discussion Starter #4
Thanks guys. it WAS good price. I took the CARB completely off though. took it all apart, let jets soaked. wiped down everything inside them. The K&N was on it when I got it. I just recharged it. Im wondering if putting some CARB clean in anyway would be good... just because it might cleans lines and stuff as well. thoughts? And since I took the CARB completely off I should probably sync it up. ALSO.... while looking at the CARB... I could only locate three screw for syncing... is that the case? and if that's the case I'm assuming you match the two sets and then use the middle screw to balance them? Thanx again.
 

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Even if you don't buy a real manometer for syncing your carbs (recommended), you can make one yourself, according to YouTube:
I've never done it this way, so this is not an endorsement... just an option to consider.
 

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Ditch the K&N. The carbs will never function right with it. Use an OEM equiv filter in the stock airbox.

Pull the carbs again. Do the full disassemble, soak the carb bodies in the berryman's chem dip 24 hours each. If you don't dip the bodies, then you will never have them clean, and the bike won't run right. The majority of the places that fuel would have seeped into and varnished up are air passages, and fuel treatment in the gas while running the bike won't get to those spots to make a difference. Fuel treatment is a preventative measure, not a fix for the katana CV carbs.

Once you have them fully cleaned and reassembled, bench sync them and bench test to make sure they do not leak fuel. (use a aux fuel source and fill the bowls, let it sit with fuel flowing... no fuel should leak.) Once verified, put the carbs on the bike with the airbox and right filter. Warm the engine, sync the carbs. This part HAS to be done or you will have terrible running issues at lower rpms.

Additionally, check the spark issues. Low light with the tank off let the bike run and check for arcing especially down in the plug wells. If you see an arc, you need to fix that. Also verify the plug wires are soft/flexable all the way onto the boots. If the last 1" or so gets really hard and stiff, I strongly suggest you pull the boots off, clip it back to the soft, and screw the boots back on snugly. Any chipped/broken boots should be replaced.

Use no fuel filters, make sure the fuel lines are re-enforced lines, and verify the petcock is flowing properly and working right. Finally also verify you don't rust in the tank or all the work detailed above is for nothing.

Krey
 

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that's a pretty incorrect statement. you will have to rejet for the k&n but to say they'll never function....
WOW. A mixture of good and bad advice, about evenly balanced.

It is never a BAD idea to have a fuel filter on an older bike.
[edit] Well except maybe if the fuel system is on the verge of having insufficient flow when working "right".

Reinforced fuel lines is just overkill on a street bike.
And lastly, if you don't take the throttle linkage apart when cleaning the carbs, a "sync" often is not required; at least not just to get it running.

OH, and I gotta admit I like what he said about the K&N.....even though it isn't totally correct. :whistle:
 

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Considering Kreylyn gave you step by step instruction on what to do to fix your bike, I think you should follow that advise. I do agree with Kreylin about the K&N filters tho just based off my own expierence with them and the 3 older Suzuki's in our stable (90 Katana 1100, 92 750 Katana, and a 94 Rf600R) You can also download a manual for working on your bike from www.carlsalter.com
 
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