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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: Liverpool Brick on January 27, 2014, 10:28:25 AM

Title: K75S crankcase breather hose
Post by: Liverpool Brick on January 27, 2014, 10:28:25 AM
Hi,
Carried out routine filters, plugs and oil service on my '91 K75S and whilst the filter box was apart I checked the crankcase breather hose which turned out to be split. Fitted a new one and yeeeeehaaaa! Its a new bike! So, my advice is check that hose and fit a new one if needs be. Its an easy, cheap repair and the benefit is that much joy abounds.
Keep 'er lit,
Andy 
Title: Re: K75S crankcase breather hose
Post by: vrmntynkee on February 17, 2014, 02:26:17 PM
Hi Liverpool, I just picked up a neglected K75. it was left out in the weather, i would say most of it's life. Its a '94. Anyway my question is did you se an improvement in engine operation after fitting new breather? This bike starts easily but is finicky on idle. Acceleration produces skipping and backfiring. I replaced the breather and vacuum nipples (they were cracked as well). I think there is a slight improvement in the running, bit still far from right.

Just looking to see if an air leak might be the problem...

Thanks!
Title: Re: K75S crankcase breather hose
Post by: Fossil on February 18, 2014, 07:31:45 PM
Start the bike and use an unlit propane torch around the throttle bodies and rubber mounts and watch for increased idle rpm. Increase in idle speed indicates a need for new throttle body rubber mounts(?) These bikes are very finicky over tiny vacuum leaks.
Title: Re: K75S crankcase breather hose
Post by: Motorhobo on February 19, 2014, 04:11:00 PM
+1 on throttle bodies hoses. I had to rebuild mine because of micro cracks probably due to weather exposure and some overheating I had because of a bad fan. Runs great now. Btw I didn't know that about the propane torch...I had to wait till the leak was bad enough to hear with a straw in my ear.

I'm sure there's a long thread on the throttle bodies rebuild in here somewhere...there's an issue with the clamps. I think you can only use oetikers on some of them because of space issues. I had to get a tool to do the job.