air filter problem

[Mad Paddy]

hi can anyone give me advice the air filter on my 08 gs had to be replaced at 7,500kms i have remus decate headers and a akr end can fitted
fuel comp went down to 32mpg
main dealer doesnt know whats the reason
pls help

 

[Steptoe]

the air filter on my 08 gs had to be replaced at 7,500kms

Why ??

 

[Mad Paddy]

dealers here in the rep of ireland dont seem to have a clue
has anyone else had the same problem

 

[Steptoe]

I'll ask again - Why change it at only 7500kms. ?

 

[John Armstrong]

Have you had it on a dyno?

 

[Mad Paddy]

what are you saying i should of changed it before 7,500kms

 

[Mad Paddy]

the filter was completely blocked up completely black
and no have not had it dynojetted

 

[Mad Paddy]

no it has not been dyno
should i get it done would that tell me why life of air filter is so low ?

 

[Deleted account 190920001]

completely black as in oily or as in just dirty?

 

[Mad Paddy]

completely black with oil

 

[Deleted account 190920001]

I am far from a GS expert only had mine a day but I would say that your getting a lot of oil up the breather, how or why I will have to leave to others but I wouldn't say its normal.

 

[Steptoe]

Your filter shouldn't be blocked at that mileage.

It shouldn't need replacing until 12,000 miles, unless you've been riding in water or sandy/dirty conditions.

How much oil do you have in the engine.
Can you see the oil in the level window. Does the glass look clear when the engine is running or is it still full of oil.

Does the bike run ok at the moment ?

Your not giving much information for us to give you much help.

 

[Mad Paddy]

sorry trying my best
the oil level was perfect up at full mark
when engine is runing clear glass
had service at time of filter changed by main dealer
bike now has 11,000kms and filter starting to get black and oily again
plus mpg starting to go down again
was getting 50mpg when serviced now getting 40mpg
will have too fit another filter within the next 2,000km i think
riding on main and a roads all the time never been off road

 

[Mad Paddy]

sorry forgot to mention that the bike goes ok but have noticed that if you dont have correct gear selected in roundabouts she spluters alot
i mean if your are in third gear doing 40mph leaving the roundabout i have too change down to 2nd gear or else she spluters like made seems to have no low down torque

 

[RickG]

The oiled up filter is the issue, or rather what's causing it to get oiled up. Once it's blocked it'll be making the bike run rich and messing up your mpg and causing missfire as the engine is short of air.

A typical cause for excessive oil ending up in the airbox is overfilling with oil, which doesn't seem to be the case as you've checked the levels and they seem OK. The other cause is high crankcase pressures caused by something like partially blocked/kinked breather pipe or, unfortunately, a blown head gasket or other reason for combustion gas to get into the crankcase and pressurise it which forces excess oil up the breather and into the airbox

Was the bike Ok before the headers and pipe went on?

 

[Mad Paddy]

the headers and end can were fitted from day 1 of the bikes life the bike was reged in march 08

 

[Kremmen]

Potential reasons for a blackened air filter, high MPG ....
Tight inlet tappets allowing some of the compressed mixture back into the air box, this could also be the reason for low MPG & spluttering at roundabouts.
Something seriously wrong with the internals causing accute crankcase compression... this will definitely cause both of the above & potentially your blackened filter.
The valve timing has slipped.... highly bloody unlikely but could cause the above.
partially blocked inlet "trumpet"

Plus loads of other potential reasons ... other than going back to your dealer, start with the basics & work through methodically.

Regards

 

[Schtum]

Tight inlet tappets allowing some of the compressed mixture back into the air box, this could also be the reason for low MPG & spluttering at roundabouts.

I guess that you'd get the same effect from burnt exhaust valves as a result of the full system, fitted from new, causing the mixture to be too lean.....

 

[Kremmen]

You certainly could, the only difference that the combustion product will be dumped in the air box instead of the exhaust.

Regards

 

[Mad Paddy]

thanks for all your info
bike is going back too dealer for the third time to try and fix it
at least i know what too check with them as posible cause