Engine Idle damage?

[nilesh_b]

Hello Everyone,

I have a FZ6 S2 2009 model.
Replaced stock exhaust with Leo Vince with cat elim pipe.

Since then it started a ticking noise..up and down the rev when its not warmed up and at Idle @ 900 RPM(Factory Setting of Idle).

Read the Idle speed should be 1250 ~ 1350 from the Factory Manual.
So upped the idle speed to 1350 and put BMC air filter too.

That has eliminated the ticking noise.

And also i am with the company specified idle.
(But when i bought it new, it came with 900 RPM. )

My question is, what implications the engine can have by increasing the engine idle to 1350?

(She also runs fine between 750 - 800 RPM without stalling )

(I increased idle by turning the screw under the left tank when engine was warmed)

Any suggestions appricaited.

 

[youngy]

The lower idle speed is more likely to do harm. The oil pump runs off the crank - if the idle is too low then the pump will not pump enough oil to the bearings.

You will probably also find that throttle response from idle is improved with the higher idle speed.

 

[nilesh_b]

Youngy,

You are absolutly right about the oil pump. Never thought about that.

I was also worried about if air/fuel ratio has been disturbed?
At idle or at high revs?

 

[Taku]

Because you have a '09 model you can detach the bikes battery for a few moments and when you connect it again it should reset the air fuel mixture for the new exhaust...

Not 100% sure as I own a '04 model so if anyone could confirm this it would be kewl.

 

[SANGER_A2]

Because you have a '09 model you can detach the bikes battery for a few moments and when you connect it again it should reset the air fuel mixture for the new exhaust...

Not 100% sure as I own a '04 model so if anyone could confirm this it would be kewl.

It will.

 

[sixsix]

My bike idles funny with the leo's but only when the db killers are out of the cans. with them in it's fine. I had made a post on that a while back with a video and everyone said it was normal. I usually don't ride with the db killers out anyway.

 

[tjhess74]

definately need to up your idle speed. most bikes are at 1k rpms or more. its also possible that when you put on the new pipe, you allowed the engine to breath easier, releasing some back pressure on the exhaust valves. this may have something to do with the tick also. my zrx did the same thing after an exhaust change. its just a theory...

 

[nilesh_b]

Thanks to all of you for your replies.

By turning the screw below the tank on left for idle + / -, what exactly it does so the engine idle can be increased or decresed?

I mean technically Does it supply more air or fuel?

Cheeers

 

[Taku]

Thanks to all of you for your replies.

By turning the screw below the tank on left for idle + / -, what exactly it does so the engine idle can be increased or decresed?

I mean technically Does it supply more air or fuel?

Cheeers

It just opens the throttle valves very little to let in a wee bit more air/fuel...

 

[opnwhlmnd]

its also possible that when you put on the new pipe, you allowed the engine to breath easier,releasing some back pressure on the exhaust valves.

A new exhaust pipe/system has no effect on the exhaust valve. The pressure on the valve is controlled by the valve spring. How far it opens and how long it stays open is determined by the camshaft lift and duration. The valve spring then closes it.

A new/different exhaust system will free up air flow out of the cylinder but will not change exhaust valve pressure.

.

 

[Kriswithak]

I've found the idle changes when I change the exhaust from stock to aftermarket, so something is going on there. May just be the bikes computer I guess?

 

[g8anos]

It's the backpressure.

I've bought the Leo's with the de-cat pipe and the removable DB-killers.

I tried all variations.

The worst idling was when I had the cat and the DB-killers removed.

There was almost no back pressure at all, causing the bike to sound and feel funny, almost sick, coughing. I was worried about my engines health.

My current and best setup is with the Cat on, and the DB-killers installed.

On low-rpm's it runs smooth like a kitty and has more torque. Idling steady at 1250-1350 rpm's.

On the other hand with my previous open-wide setup I had a rocket on high-rpm's, but no punch in the low-range.

 

[Nelly]

Numpty in the UK installed Leo's and a K&N filter.
It ran a bit lumpy and had a flat spot. He was advised to put the stock filter back in and it fixed the problem.
BTW idle speed should be set at 1250 - 1350 rpm in accordance with the manual.

Nelly

 

[iSteve]

Back pressure is needed for good low rpm performance. Valve timing is setup for mid to high rpm allowing some unburned fuel to escape at low rpm's. Back-pressure can help keep these unburned fuel in the chamber longer to be more completely burned. The problem with back-pressure is at high rpm's when you need the gasses to exit as fast as possible.

 

[p-dawger]

Sorry to mention the obvious but are you sure you do not have an exhaust leak? Once it warms up things expand, closing the leak slightly...but that ticking might just be a leak that you can hear when it is cold. (Read noisy valve clatter)

If all was fine before the change - look at what you changed - don't compensate for one issue with adjusting another.

I would return the idle back to factory specs - just me.

Sounds like a leak to me. Also check your header bolts on the exhaust manifold, if they were a bit lose to begine with they may have gotten more loose with tugging on the exhaust system...in other words go thru the whole exhaust and ensure you have no leaks anywhere.

 

[FZ6-ZN]

One answer: Power Commander, with custom map.
After fitting a PC to my FZ6 with custom map, my bike revs to redline without a murmur and idles as smooth as can be.
FZ6-ZN - Sent from my iPad using Tapatalk...

 

[FinalImpact]

Interesting read!

I'll add this: at low RPMs you do have less oil pressure. At low RPM's the CAMs lobes likely induce feedback into the cams drive chain making it slap around or "tick" if you will. But the Tic could be an exhaust leak too.

Another factor is oil cooling from oil being slung about inside the engine. It needs to fly far enough from the rods to lubricate the piston, wrist pins and cylinder wall, as well as circulate the engine water coolant.

Adding to this, the charging system may not be effective below 1100 rpm and the battery could be loosing voltage which could in itself create misfire conditions for various reasons.

I'd say on the later model bikes, it'd be wise to pull the ECM fuse when you modify the exhaust Period! That includes slipping in the DB killers or taking them out. Although I suspect it does adjust over time, pulling the fuse will either A) save your catylitic converter from overly rich conditions or B) save the engine from lean conditions induced by back pressure changes in the exhaust!

 

[lrojasma]

That´s exactly what is happening. That´s why the bike has CO2 adjustment, i did that adjustment using values from other users from other forums and jerkiness went all away and performance improved, althought i would expect a little less gas mileage.