hey all,

I've had some problems with my kay since i got it (you can look up my problem with a power loss in mid rpm range - i thought it was the HT leads but it came out to be this air leak today) and i went to my BMW friend who checked the air leak for me and yes, there's a pretty serious airleak in the first (from the front wheel) butterly... - we checked it using a brake cleaner. the engine, when cold rattles but gets better when hot. it looses power from time to time but when it happens, i close the throttle and open it immediately and it's gone. i know that those things are just "unfixable" but who knows, maybe there is a solution for such problem and you guys know it? anyways, i would be very grateful for any ideas or suggestions.

thanks a bunch,

throttle body ?....or like most of us have found ....the rubber tubes between throttle body and inlet manifold and plenum chamber / throttle body ?





if in fact you mean those rubbers .......check this thread ..... lots of information



http://k100rt.aforumfree.com/t1651-leaky-intakes-rough-running

Yup, BTDT, more than once. It MAY be just the seating surface at the head where it is leaking and if so, removing the boot, resealing and remounting will fix it. However, these boots split at the clamp after a long time, and that won't be fixed by anything other than a replacement. I would highly recommend just replacing all four boots, and the pinch clamps, since you have to pull everything off anyhow. It's not too cost prohibitive, and then you don't have to go back into it again. And go back into it again... and... (ask me how I know...)

Read this when you have 15 minutes:



http://k100rt.aforumfree.com/t1651-leaky-intakes-rough-running

hey,

he was spraying the cleaner so i didn't see exactly what was he doing but he said it is the throttle body (on the side, where the "thing" spins when you operate the throttle - sorr but i couldn't find an english word for that). since he checked it though, the engine started running way better when cold (probably it sealed the hole for some time. i checked it again today and nothing happened... i think i will just change all the rubbers as they are not that expensive. i'll keep you guys updated as i will probably need some advice on what and how;)

cheers!

an excelent idea paj ....good luck !!!

please let us know what happens and what you find .....



cheers

Hmm I'm a little confused (normal state). When you are looking at the throttle bodies (TB's), are you talking about the right or left side of the TB's?



On the right side of the TB's is a crankcase venting tube that hooks into the TB rack. That tube always cracks with age and lets air in, causing rough running. If your friend was spraying in that area and the engine smoothed out, it could be that tube, which is an easy replacement.

i think paj was saying, the butterfly shaft on number 1 cylinder tb clubbie ...ive been noticing that there seems to be some wear associated in the bushings /shaft bearing surface ...im guessing he meant the linkage arms to butterfly actuation lever .



i guess wherever there is a little movement in this area that the pulsing nature of the whole thing.. wears the bush/shaft excesivly over time and allows leakage

just like charlie said - i meant the no1 cylinder and i meant the shaft...i'll have to take it all apart and inspect, but maybe when those damn colder days will come. as for now, i'll try to enjoy the ride:)

Technically the engine crankcase venting hose goes into the airbox upper and from there dissipates any excess engine oil vapour through the throttle bodies...that's, of course, at the back side or looking at them the RH side of the TBs. The throttle cable pulls from the TB's centre so any wear from years and miles of use should be spread out. Unlike the Oilhead twins which wear their TB shafts out quite easily, the old Ks don't have a big problem there. But that doesn't mean it isn't worn. The devil is always in the details and a close look while performing any diagnosis is what's required. Otherwise it's all guess work. Don't we know it.

summing up all the things you guys said, probably the rubbers are the problem and he just made a not very precise diagnosis. we'll see. i think i will take care of it next month and will pudate you guys. thanks a bunch

This looks like a good spot to post my picture of no.4 air boot and attached oily grunge at the top.
Does anyone know if this is caused by a particular sort of leak?. This is the cylinder whose spark plug keeps getting black soot on the
top.
Tks
RT

RT is it missing or popping when you turn it off ? if so could be running lean causing a back fire back up the chamber especially if its burning oil

RT,
When I had oil in that area it was coming from a split breather hose...... just a thought.
Paul.

rt that looks typical ...the oil vapour comes from the breather out of the engine ... i guess you could undo the clips to the tb rubbers and clean it up ...

im going to ask "cafe racer" about the suzuki clamps (like standard) that someone mentioned in a post last year some time , for when i do my rubbers .

i must ask (in a new thread ) if the amount of vacume applied to the crankcase is excesive , couldnt it be reduced some ?

i guess the amount of vapour flowing up to that area is proportional to the leaks through the engine seals (output shaft , starter ,altenator drive , timing cover etc ) and not forgetting blow by from rings .

as an asside i undid my idle adjuster screws last week and cleaned them up ...the last 2 cylinders were soaked with oily crap and might explain why your number 4 spark is always dirty

No missing or popping, just a bit uneven idling when cold now. Looks like I have to get in there and have a closer look for leaks, Tks men.
RT