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Hi. I've just installed a high flow air filter into my Sinnis max, I also bought a bigger main jet but I ordered the wrong one so I wasn't able to fit it. The bike runs fine but I would immagine that the fuel to air mixture is rather lean now and what worrys me is I've heard that this can cause damage to the engine if it runs too lean, is this true? Also when I accelerate I get this fairly loud roar which I assume is comming from the new air filter, is that normal?
it'll run hotter being more air to fuel but then again it'll run hotter having more fuel when you make it richer its the same sort of thing but it will definitely run dryer when lean
Kennon
Sooooo is it going to cause damage to my engine or will it just reduce it's life span a bit? I was planning on getting an oil cooler to counteract the extra heat.
they run pretty lean standard so allowingmore air in has made it even leaning so it will make your engine life shorter, perhaps a oil change should be done to freshen things up once youve got it rejetted
Alright I'll do that, cheers.
unless you know what the standard jetting was you cant be sure its too lean now
to check it
hold it full noise in top gear on a flat road or very slightly uphill
chop the throttle, pull in the clutch and hit the kill switch
all at the same time ...hahaha
when the bike comes to a halt remove the sparkplug
correct mixture is shown by a light tan color on the center electrode
rich is black
lean is white or any kind of grey
lean is bad because it is running hot and prone to detonation
in extreme cases this can lead to an internal meltdown
a rich mixture will actually run cold because all the fuel is not burning
but it is evaporating so cooling the engine also the fuel is washing away oil in the cylinder so rich isnt good either
one jet size up should be right if the mixture was correct before you started tinkering
Thanks for the advice, I'll have to try the spark plug thing soon. I've been for a 200+ km drive today and it didn't blow up or anything so I'm not in any immediate danger. Before the air filter change my spark plug was a little bit white so it must of been a little lean anyway so I'm moving from a 97.5 jet to a 105.
you have 3 jets whats lean at idle to 1/2 throttle , it pretty much ok to be lean , 1/2 to 3/4 you need littl more attention to but most importantly is 3/4 to wide open throttle
you cannot ride normally stop and check plug , itll only show idle mix , as he said ride it get throttle to correct position and kill switch it then check plug , to know your lean condition thru all 3 jets
to note , all 3 jets "stack" , each add toward WOT mixture , if your lean at idle to 1/2 and 1/2 to 3/4 you may still be lean at WOT even with a fairly large main jet
I recently upped main to over a 105 , combined with my airflow (ram air) mods at 75 I am still lean , so I need to upsize my Needle jet ( 1/2 to 3/4 throttle jet ) as well
popping and "chugging" under acceleration is a very good indicator of a "dangerously lean" condition ( I still pop n chug at almost full throttle , drive that way for long = dead motor )
well I've moved from a 97.5 jet to a 105; there's definitely a performance increase but it seems minor, I haven't had a chance to test it on a dual carriage way yet. I noticed no popping, chugging or any abnormalities before or after the re-jet so I guess I'm in the clear. Cheers for the advice guys!
By the way the sound from the new air filter is incredible, espessially when accelerating hard! I'd definitely reccommend it to anyone! It only cost £6 which is a bonus and I celotaped half a fanta bottle around it so it dosen't suck up any water.