2005 katana 750 bad engine vibration

[matt290477]

Hello, I'm glad to have found this forum. First of all, I am a French Canadian so please forgive my english mistakes. I own a 2005 Suzuki Katana 750, which had develop an engine vibration. Now the vibration are so bad that I can't barely ride it for more than 20 min. before having numb hand and feet. I know the vibration is engine related because I can feel it in neutral on the centerstand. I feel it through footpegs, handlebar, fuel tank, plastic buzz. It vibrate from idle and get worst with higher rpm. The bike have now 20,000 km (12.000 miles) I have adjusted the valves clearance twice, sync the carb with the motion pro carb sync tool, I still have the vibration, and also a slight idle bounce. It's sound like a engine imbalance, but I do not know how to fix it. Can someone help me? Thank you
Matt

[joseph2027]

ok rirst it's a kat. it does that/ mines a 04 600 and after 20min. both hands are knumb. put some bb's or lead shot in the handlebars. that will help.as far as your feet replace the peg bushings / i just hade to do that mysefl.ive got 6200 mlies on my kat. hope that helps

[katman05]

Hey Matt, welcome to Katriders. I also have a 2005 750 and would like to see what you mean about the vibrations. I live in Montreal and could meet up with you somwhere. I'll send you a pm with my phone number.

Matt, did you always have the vibration or did it just start one day?

[Helmet_Hair]

Hey Matt, welcome to Katriders. I also have a 2005 750 and would like to see what you mean about the vibrations. I live in Montreal and could meet up with you somwhere. I'll send you a pm with my phone number.

Matt, did you always have the vibration or did it just start one day?

I think you should answer that last question in order to rule out anything serious going on inside the engine.

[Maxxrox]

Quick interjection here:

Just because it's a Katana doesn't mean it's supposed to vibrate. Mine's an '01 600, and it's smooth as butter. Grips are solid as a wet brick; no vibrations in the hands, no numbness.

If you're gettin' that kind of a buzz out of the engine, you need to start hunting the problem. That's not how they're supposed to run.

On topic:

The first suggestions I'd give on curing vibrations would seem to have already been covered; carb sync and valve adjustment. Have you checked to make sure your plugs and wires are in good condition? If the timing were off, you might have some vibration issues, but it's really not adjustable on the Kat..

Anyone with more familiarity: couldn't a bad/malfunctioning TPS cause vibrations, especially at throttle?


--B

[matt290477]

It always had a small amount of vibration but it became worst during the season. I will try to clean the carb, and have a mechanic with an exhaust analyzer check the jetting, maybe I have a carb too lean or too rich something like that

[Helmet_Hair]

How many miles are on your oil? I've found smoother running with a good synthetic oil.

[matt290477]

I just changed the oil today, I'm using a good synthetic 10w40 oil. Still have the vibration, all rpm range, feel through the seat, tank, footpeg handlebar, it's sure it's not "normal" vibration.

[The CyberPoet]

Still have the vibration, all rpm range, feel through the seat, tank, footpeg handlebar, it's sure it's not "normal" vibration. and has set valve clearances & sync'd carbs, plus vibration is 100% engine dependent (still does it in neutral)

That combination of data means only one of two things in my book:
(A) Something is loose that should be tight, such as missing the rubber support for the bottom of the oil cooler, or the rubber pad under the tank's front support, or one of the front engine support rubber isolators. OR
(B) The jetting is so extremely lean that the fuel is literally knocking.

I would guess the problem probably is in the jetting and that the carbs are partially clogged (OR you have water in the float bowls), and that increasing the richness of the mixtures (by cleaning and/or installing a jetkit) will resolve the issues; I hope the knocking has not done any damages to your pistons.

(there is a third possibility involving the valve clearances, but I will trust that you used the right values in setting & tightening them).

Cheers,
=-= The CyberPoet

__________________________________________________ ________
CyberPoet's Katana Maintence and Upgrade Parts Offerings
The Best Metal Steel Aluminum Motorcycle Tire Valves in the World, plus lots of motorcycle & Katana (GSX600F / GSX750F) specific help files.

[matt290477]

It has been checked by the dealer today. they check the carbs, plugs ,fasteners, engine mounts, they said all is perfect, all katana vibrate a lot. Wow! I had a exceptionnal motorcycle , because it had no vibration before. Now it's '' normal''

[rexazz2]

I am guessing there is a reason the handle bar bracket sits on rubbers on the 750's but are solid on the 600's

[The CyberPoet]

It has been checked by the dealer today. they check the carbs, plugs ,fasteners, engine mounts, they said all is perfect, all katana vibrate a lot. Wow! I had a exceptionnal motorcycle , because it had no vibration before. Now it's '' normal''

Dealers generally pay lip service to vibes as a complaint, since they know 90% of the cases is rider-based, with the rider gripping the bike too hard and making the normal vibes perceivably worse. But a Kat should never get worse with distance -- normally they get better between new and 10k (as the engine beds in), and with a good carb sync at the 7500 valve adjustment they are really smooth.

Cheers,
=-= The CyberPoet

__________________________________________________ ________
CyberPoet's Katana Maintence and Upgrade Parts Offerings
The Best Metal Steel Aluminum Motorcycle Tire Valves in the World, plus lots of motorcycle & Katana (GSX600F / GSX750F) specific help files.