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Main Area => General GS500 Discussion => Topic started by: brown.rw on May 14, 2008, 06:47:21 PM

Title: two questions
Post by: brown.rw on May 14, 2008, 06:47:21 PM
Alright, after a long time of trying to get my bike fixed and even longer waiting on parts my bike is running with great power again.

there is however a problem and I am hoping it is just some bad gas. The bike accelerates great and has plenty of power, but when i release the throttle at any rpm the there is a sputter sound from the exhaust. reapply power, the sputter goes away, let go of throttle, sputter returns. the lower the rpms fall the fewer sputters and it idles without an issues.

thoughts?

Second questions...and yes, this is an ignorant one. Before getting my bike and taking the safety course I was (and still am) driving a manual 4runner. I keep the rpms low in this to save gas. I know that I should be around 4-5k taking off with the GS, but what rpms should I aim for while riding?

All of your help is greatly appreciated. thanks again from FL.
Title: Re: two questions
Post by: ajaxgs on May 14, 2008, 06:50:53 PM
Quote from: brown.rw on May 14, 2008, 06:47:21 PM
, but what rpms should I aim for while riding?




5-6 k will give you good power to get away from any obstials (soccer moms in mini-vans talking on the cell phone) and will give you good mileage as well
Title: Re: two questions
Post by: 08GSSteve on May 14, 2008, 06:53:40 PM
the splutter or slight backfire is normal as motorcycles are run so bloody lean.

There is a thread explaining this issue but to be honest unless it is BAD I would not worry about it.  I think it sounds kind of cool myself to get that crackle when backing off the gas at high RPM.

I will try and find the thread and post the link.
Title: Re: two questions
Post by: 08GSSteve on May 14, 2008, 06:57:17 PM
check this it may help you to understand backfire.  :thumb:

http://gstwins.com/gsboard/index.php?topic=41164.0
Title: Re: two questions
Post by: scottpA_GS on May 14, 2008, 07:44:46 PM
Quote from: 08GSSteve on May 14, 2008, 06:53:40 PM
the splutter or slight backfire is normal as motorcycles are run so bloody lean.


No. I disagree a bit.

If your GS is backfiring there is something wrong  :thumb: The air/fuel mixture is off. While yes, the GS does run lean, backfire is not an acceptable thing. Under "normal" circumstances its not a good sign. If you leave it unchecked you can cause damage and have problems down the line  :thumb:
Title: Re: two questions
Post by: guitarking135 on May 14, 2008, 08:48:07 PM
I usually run around 6-7k Maybe its my bike personally but it lags when lower than 6k. But yea the back fire is probly because your lean. Might try a rejet
Title: Re: two questions
Post by: guitarking135 on May 14, 2008, 08:51:00 PM
also maybe check your air filter. I know mine does that a little too and I know my air fiter is filthy . almost 10,000 miles on the factory filter. Hey any one got an air filter for sale possibly a k&n?
Title: Re: two questions
Post by: 08GSSteve on May 14, 2008, 09:21:26 PM
www.mikuni.com/tg_backfires_in_exhaust.html

According to the Mikuni site backfire is a norm especially after a performance exhaust is fitted and in fact SHOULD be expected from a well tuned engine.

Read the site and judge for yourself.
Title: Re: two questions
Post by: ohgood on May 15, 2008, 03:27:02 AM
Quote from: brown.rw on May 14, 2008, 06:47:21 PM
Alright, after a long time of trying to get my bike fixed and even longer waiting on parts my bike is running with great power again.

there is however a problem and I am hoping it is just some bad gas. The bike accelerates great and has plenty of power, but when i release the throttle at any rpm the there is a sputter sound from the exhaust. reapply power, the sputter goes away, let go of throttle, sputter returns. the lower the rpms fall the fewer sputters and it idles without an issues.

thoughts?

Second questions...and yes, this is an ignorant one. Before getting my bike and taking the safety course I was (and still am) driving a manual 4runner. I keep the rpms low in this to save gas. I know that I should be around 4-5k taking off with the GS, but what rpms should I aim for while riding?

All of your help is greatly appreciated. thanks again from FL.

thoughts:

sounds like your header may be a little loose, letting in air, and causing the backfires. check your header bolts n stuff. your mixture is likely lean too, like the others said. an occasional 'pop' or 'crackle' on deceleration is normal, but a full back fire "POW!" shouldn't happen.

rpms:

whatever your riding style dictates. keep in mind the charging system usually doesn't work well until >4,000 rpms. start offs from redlights (for ME) are fine from 1500-2000 rpm, then i'd guess it's around 5,000 rpm since the sound is nice there. i average 50-60 mpg depending on the mood. that's with a rich jetting, K&N filter and V&H open pipe.

:)