GSF750 (GSXR750 91 engine): noise : Suzuki GSX-R Motorcycle Forums: Gixxer.com

**hapchu** · 07-08-2010, 11:38 AM

It runs OK, but makes some noise, when 1-4k RPM.
This sound recorded on 115 C engine after one hour street run.
Is it chain?
When it hot over 80 C, it makes some low freq "bom-bom-bom" under the clutch cover at 1200-2000RPM (after 50sec in sample).
Is it clutch, trunsmission, bearing?
http://files.me.com/hapchu/qk6wv3.mp3 (635Kb mp3)

**freezehawk** · 07-08-2010, 12:12 PM

Not an expert on oilers, but it sounds healthy to me! And by healthy i mean all that noise typical of these SACS engines. :-)

Hawk

**hapchu** · 07-08-2010, 12:22 PM

Sounds optimistic, thanks!

**SNAKEYES** · 07-09-2010, 11:01 AM

Does it vibrate a lot when you do that? You might be able to clear some of that up by synchronizing the carbs. Other then that sounds good. These bikes have more audible top end noise, then newer bikes.

G/L

**hapchu** · 07-09-2010, 12:56 PM

It vibrates a little to 4k RPM, maximum vibrations are about 5.5-6k RPM.
I'll check valves and chain tensioner, and sync carbs tomorrow.

**GSXR Tony** · 07-09-2010, 01:01 PM

Quote:

Originally Posted by hapchu

It runs OK, but makes some noise, when 1-4k RPM.
This sound recorded on 115 C engine after one hour street run.
Is it chain?
When it hot over 80 C, it makes some low freq "bom-bom-bom" under the clutch cover at 1200-2000RPM (after 50sec in sample).
Is it clutch, trunsmission, bearing?
http://files.me.com/hapchu/qk6wv3.mp3 (635Kb mp3)

I mean, a recording played off the internet isn't perfect, but your engine sounds completely normal to me? Sounds like every other air cooled oiler with quiet exhaust I've ever heard?

**hapchu** · 07-09-2010, 01:09 PM

Quote:

Originally Posted by GSXR Tony

I mean, a recording played off the internet isn't perfect, but your engine sounds completely normal to me? Sounds like every other air cooled oiler with quiet exhaust I've ever heard?

You are asking me something? Or "?" = "!" ?

Thanks anyway.

**freezehawk** · 07-09-2010, 01:11 PM

I guess the vibration is something to be expected in a way, since this engine doesn't have a balancer shaft like some Honda's/Yamaha's do. Carbs out of synch will cause some heavy vibration at low RPM's, and some additional noises.

Hawk

**hapchu** · 07-13-2010, 01:57 AM

Yes, it was chain!
After chain tensioner inspection and pushing tensioner one click inside it makes two or three times less noise! It is noticeably especially on cold engine.
120C engine sounds: http://files.me.com/hapchu/jlrh8t.mp3