Sealing the Air Cleaner/Filter Frame to the Air Box

[DevoutClient]

Hi everyone,

Using the guides and the advice of several people on the forum I've gotten my GS850L running (sort of, more to follow). Because I'm still working on ordering the parts and assembling everything I've gotten the bike to start with just the carbs on and it idles surprisingly well...until the bike starts to warm up and then it behaves as though it has a vacuum leak (increasing idle speed, hanging rev after throttle blip, classic signs). HOWEVER, mounting the airbox to the carbs, and then the slide covers to the airbox resolves the issue so I'm thinking that with a properly installed/sealed airbox I'll be able to move onto final carb tuning (as many people have previously pointed out, these bikes seem to need breath in a VERY particular way...I'm out of my depth on fully understanding CV carbs but I'm guessing it has something to do with the pressure differential on either side of the diaphragm?)

As a part of my plan I've noticed as the Air Filter "frame" slides into and out of the airbox it is not an exceedingly tight fit to the top of the initial "chamber" and I'm curious to know if i should place some weather stripping on the top surface of the filter frame to try to mitigate air bypassing the filter. Back in November when i first got the bike I remember scraping some old nasty gunked up foam off the surface but couldn't tell if it was left over air filter foam or something else. Any recommendations or advice? I've included a photo of the surface I'm talking about for reference.

 

[bwringer]

Yes, you need to seal the filter to the airbox.

So your instincts are correct. Clean that surface then apply foam weather stripping so dirty air can't bypass the filter.

I also apply a little grease to the weather stripping so that it will slide into the airbox without ripping the foam off.

The rubber snorkel on the back of the airbox is also very important to shafties.

 

[fastbysuzuki]

There is a good tutorial for the airbox on bikeclff site http://members.dslextreme.com/users/bikecliff/ but I cannot get the link to work
shame as it's decent.

 

[Rich82GS750TZ]

Try this one
http://members.dslextreme.com/users/cbsaunders/gs/airbox-sealing.pdf

 

[DevoutClient]

That website of his just keeps giving and giving...I need to look more closely on that website before posting questions. I took a look at the "airbox sealing" tutorial and the "air intake repair" tutorial. Very helpful information. I can't tell you all how appreciative I am for your responses and advice, thank you!