Backfiring, air leak in front - exhaust manifold?

[Roadinator]

'05 Girly with 57k started backfiring recently.  I actually used the search engine and found out that 1) this can be normal, 2) sometimes backfiring can be attributed to air leaks.  Sounds like air is spitting from the front of the motor (new sound).  It's kind of hard to hear a specific location with your head down there while the engine is running, but I'm guessing it's the header gasket.  I tried to find out more info about the header and it looks like they have individual gaskets on each pipe.  Is this correct?  Would a leak at one of them cause a backfire or could there be something else in that area that could be the cause?  If it is the header gasket, I guess remove and inspect and go from there?

Thanks for the help!

[Roadinator]

So I couldn't get to the headers (so far), just moved and my tools are spread out and I need my large torx head to get the crash bars off.  I decided to look at the air filter and spark plugs.  The air filter looks pretty crudy, but it is a K&N and I can clean it and reuse.  The air sound is getting louder and almost sounds like a spark plug, but I'm guessing it would start running bad if it was?  I will look over the vacuum lines to see if one is splitting or something.  Anything else I should look for while the tank and air filter box are off?

[Sin_Tiger]

If it was a spark plug I think you would have seen the evidence in the way of smoke by now.

[Roadinator]

Yes, I figured it probably is not a spark plug, but I will pull and see what they look like.  The sound is more like a vacuum sound and not spitting from a header, but I am just guessing.  I did look into the carbs and they look discolored on one side.  Not sure if that is normal for 57k or has anything to do with performance (seems to run fine).  Should I try and clean that?

Nice to get into the mechanics of the bike.  Wish I could find my Haynes manual, but it is in a box somewhere or my son grabbed it thinking it was his...

[Sin_Tiger]

  I did look into the carbs and they look discolored on one side. 

I'm guessing that was a slip of the keyboard and you meant throttle bodies? Bixxer is probably the best man here to advise on this. 

[Roadinator]

Yep, typing without thinking.  I was going to call them the butterfly valves, but I am not sure if that is correct.  I pulled the headers and everything looks good.  The bolts were not very tight, so I'm not sure if that was the issue?  Maybe one was working itself loose?  The plugs look good and the service manual I received with the bike said they were replaced not long ago.  the air filter was cleaned not long ago as well, but it needs to be cleaned, so I am off to get a K&N filter cleaning kit.  I am assuming it is okay to use the K&N oil on the filter for a Tiger?  I was also going to put a little exhaust gasket sealer around the header seal.  Any reason not too?

Putting it all back together this afternoon and will see.   

[metalguru]

While you have the tank off, take the airbox off and check the pipes from the Idle Air Control valve to the throttle bodies, there are 3 of these, quite a normal problem for these to split where they join the Throttle bodies as they turn quite tightly. Replace with thick wall silicon vacuum pipe in a colour of your choice.

[Roadinator]

Thanks Metalguru.  Guess what I found?  One line was split and barely going into the IAC!  I wonder if that could be the sound I was hearing (guessing so).  Can I take that to my local auto parts store and find a replacement?  That's what I'm gonna do, guess I could find lines to replace the all of them.  Would like to get it back together instead of waiting for parts.

Feel a lot better about finding something!  Thanks for helping! 

[metalguru]

That will certainly be the noise you heard.
If you go to your local car spares store and ask for thick wall silicone vacuum pipe with an ID of 5mm, you can even have a choice of colours too! 3ft will be plenty and replace pipe for pipe.
Don't forget the IACV gasket to airbox as they disappear.
If all else fails there are plenty of vendors selling on the net via ebay.

[Roadinator]

My local auto parts store did not have any.  I see ebay has some like this: http://www.ebay.com/itm/High-Performance-Silicone-Vacuum-Hose-3-16-ID-5mm-0-100-Wall-Thickness-BLUE/260972305758?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222008%26algo%3DSIC.MOTORS%26ao%3D1%26asc%3D20131003132420%26meid%3D7208888327067115485%26pid%3D100005%26prg%3D20131003132420%26rk%3D2%26rkt%3D6%26sd%3D251011031968&rt=nc

Would that do the trick?  Do I need to worry about the ends and staying on the?  Not sure about the IACV gasket.  Everything looks fine around it, but is that something I will need to remove to get the hoses on and then fix it with gasket glue if the gasket on there breaks about?

[metalguru]

That's the stuff. Minimum length order 3ft.
You will find that 5mm is a good fit on the stubs and glue is not req'd on the gasket.
Just replace one pipe at a time as there are 4 ports on the IACV but only 3 in use. Leave IACV bolted in place when replacing hoses.

[Roadinator]

Sounds like a plan.  Tempted to try and fix my broken side stand holes by pulling the engine and taking it somewhere, but that seems like a lot of work.  How close am I to getting the motor out with the gas tank, battery box, air filter and exhaust off the bike?  I am guessing coolant lines, throttle and clutch cables and a few bolts?  Plan was to drive the bike to a place and let them weld up some fixes.  That sounds way easier...

Thanks again metalguru, think I will go for blue 

[Mustang]

Sounds like a plan.  Tempted to try and fix my broken side stand holes by pulling the engine and taking it somewhere, but that seems like a lot of work.  How close am I to getting the motor out with the gas tank, battery box, air filter and exhaust off the bike?  I am guessing coolant lines, throttle and clutch cables and a few bolts?  Plan was to drive the bike to a place and let them weld up some fixes.  That sounds way easier...

Thanks again metalguru, think I will go for blue 

do you know how bad welding distorts metal ? especially aluminum castings..........
you really need to bring it to someone who specializes in aluminum welding .
anyone worth a shit won't touch that unless it's stripped off the bike and engine.
back to your q, engine out is 15 minutes away from where you sit now , 30 if your slow .

[Roadinator]

Sounds like that might be the best thing.  I have a couple of leads on folks that do aluminum and a couple of machinist friends in case I need something made.  I just hope I can get this thing back together when it's done. 

[Roadinator]

Decided to get everything back together and then ride it on Monday to a place that said they will look at fixing the broken side stand.  Felt good to take it apart and get it back together (with some nice blue silicon vacuum hoses).  The bike fired up and is running a little rough and the orange engine light is on.  I read on the forum it takes three warm up/cool down cycles to get the light off.  I don't remember if the battery was first and last for the order and with it having a vacuum leak for a week,  I'm guessing it will probably need to get the right tuning again or will it sort itself out?  Can do the 12 minute tune and see, but first I am going for a ride.  I let it warm up and then throttled it a bit and was sputtering sometimes and then would go to a really low idle and kinda chug, chug back up to normal.