new to forum/1981 Kaw 1000csr/ blowby question

Hi Guys, this is my first post ever. I could probable search the forum for the answer to my questions, but I am lazy. Besides, maybe there are improvements in the answers over time.
First of all, I removed the smog valve, and just looped the hoses so they connect the two nipples on top of the valve cover, instead of connecting to the smog valve. I bought my bike used, and have always had oil leaks from the head in the usual places-tach drive, head gasket.
The engine leaks oil from underneath the valve cover bolts, and the head bolts like it is being pumped up the bolt holes. Could this be excess blowby pressure? Can I check this by removing the oil filler cap and just placing my hand over the filler hole? Can the breather on the top back of the engine plug up? Do those hoses that used to go to the smog valve provide blowby pressure relief back to the air box?
The second question may belong in the carb section, but since we are here, and the question is clear cut......
Stock Mikuni BS34 carbs... I have torn/ruptured enrichment shaft boots. I have had my carbs TOTALLY apart before, so I know a little about them. Can the torn boots cause rough, unpredictable warm up idling. In other words, are torn boots a vacuum leak.

Thanks to all who respond. I love my bike- it makes me feel tough, like walking around the block with a macho dog. David

I assume u have retorqued the valve cover and head bolts to spec?U should be running 1-2 pounds of oil pressure at idle and 5-6 pounds at 3500-4000 rpm.Taking the oil filler cap off and putting ur hand over it will result in an oily hand but not much info.I would replace the valve cover and head gaskets and see if this doesnt fix ur leaking problem before I started trying to dx a ring blow-by problem that may or may not exist.Blow-by usually shows up as oil fouled plugs or excess oil smoke in the exhaust.bj

blow by would show up through the crankcase vent on top of trans below/behind carbs,or lots of oil in bottem of stock air box if your still using it

1981jmotor wrote:

Hi Guys, this is my first post ever. I could probable search the forum for the answer to my questions, but I am lazy. Besides, maybe there are improvements in the answers over time.
First of all, I removed the smog valve, and just looped the hoses so they connect the two nipples on top of the valve cover, instead of connecting to the smog valve. I bought my bike used, and have always had oil leaks from the head in the usual places-tach drive, head gasket.
The engine leaks oil from underneath the valve cover bolts, and the head bolts like it is being pumped up the bolt holes. Could this be excess blowby pressure? Can I check this by removing the oil filler cap and just placing my hand over the filler hole? Can the breather on the top back of the engine plug up? Do those hoses that used to go to the smog valve provide blowby pressure relief back to the air box?
The second question may belong in the carb section, but since we are here, and the question is clear cut......
Stock Mikuni BS34 carbs... I have torn/ruptured enrichment shaft boots. I have had my carbs TOTALLY apart before, so I know a little about them. Can the torn boots cause rough, unpredictable warm up idling. In other words, are torn boots a vacuum leak.

Thanks to all who respond. I love my bike- it makes me feel tough, like walking around the block with a macho dog. David

Hi David

J motors were oil leakers so your situation is not uncommon. Back when they were new, I replaced several porous cylinder blocks under warranty. Head gaskets were common leakers as well.

Degrease the motor then spray it down with spray powder where you suspect the leaks are. Foot Powder works excellent for that.

Turn up the idle to about 1800 - 2000 RPM and seal off the crankcase breather opening. That will pressurize the crankcase relatively quickly. Start looking for brown spots where you sprayed the powder. Generally, they'll show up plain as day in a couple of minutes.

If the leaks don't show after a couple of minutes, either put a fan on the motor or ride it a few miles and have a look.

After you've pinpointed the leaks, you'll have a better idea at the solution.

If it turns out you have to do a head gasket, either do or have a leak down test done on the cylinders so you can see what the health of the valves & ring seal is.

Get the head decked while it's off. If it's a high mileage motor, get a valve job with new valve seals and guides if needed. It's possible the guides may still be good. Those cast iron guides held up a lot better than the bronze guides did in the Z motors.



Larry C:)

Thankyou to all who replied. I have not tried retorquing my head bolts yet. I think I can take them off one at a time, and put brass sealing washers underneath them, and the valve cover bolts after using the footpowder/forced blowby suggestion. Not all of the bolts are leaking the oil, and the amount is minor compared to the head gasket.
I am a real cheapo, shade-tree mechanic, Larry C, and I really had planned on just R and Ring the head without extra work. The engine runs good, and does NOT smoke. I think what oil it consumes is the head gasket leakage. I do not mind adding oil, but the front, and bottom, and side of the motor never stays clean for very long because of the oil leakage, and that does bother me.
For me, a compression test is easy, for I do not mind buying a compression tester. I will have to Google a cyl leakdown test. My bro has an air compressor, and I assume I could make or buy a fitting to apply air pressure to the cyl thru the spark plug hole.
So, in conclusion, I will retorque those head bolts, and install brass washers where needed. I might use the paper towel stuffed in the slot trick temporarily to keep the oil from blowing onto my foot. Ultimately, I will determine the cyl balance and compression before pulling the head. I personally think my valves/seals/piston rings are in great shape.:ohmy:
A parting question: if I spray the rough aluminum with muratic acid, and carefully keep it off the polished side covers, will it brighten up the metal w/o damage? I have tried almost everything to get the head/cyl metal looking good- Simple Green, cleansing powder, steel wool, scotch-brite pads... and still am not real happy with the look of the metal..

I am using the air box, and it is completely dry. I just wondered why in the world oil would be coming from underneath not just the head bolt heads, but the valve cover bolt heads as well. I do think the gaskets have anything to do with this.

1981jmotor wrote:

Thankyou to all who replied. I have not tried retorquing my head bolts yet. I think I can take them off one at a time, and put brass sealing washers underneath them, and the valve cover bolts after using the footpowder/forced blowby suggestion. Not all of the bolts are leaking the oil, and the amount is minor compared to the head gasket.
I am a real cheapo, shade-tree mechanic, Larry C, and I really had planned on just R and Ring the head without extra work. The engine runs good, and does NOT smoke. I think what oil it consumes is the head gasket leakage. I do not mind adding oil, but the front, and bottom, and side of the motor never stays clean for very long because of the oil leakage, and that does bother me.
For me, a compression test is easy, for I do not mind buying a compression tester. I will have to Google a cyl leakdown test. My bro has an air compressor, and I assume I could make or buy a fitting to apply air pressure to the cyl thru the spark plug hole.
So, in conclusion, I will retorque those head bolts, and install brass washers where needed. I might use the paper towel stuffed in the slot trick temporarily to keep the oil from blowing onto my foot. Ultimately, I will determine the cyl balance and compression before pulling the head. I personally think my valves/seals/piston rings are in great shape.:ohmy:
A parting question: if I spray the rough aluminum with muratic acid, and carefully keep it off the polished side covers, will it brighten up the metal w/o damage? I have tried almost everything to get the head/cyl metal looking good- Simple Green, cleansing powder, steel wool, scotch-brite pads... and still am not real happy with the look of the metal..

Whenever we had a bike come in that was covered with oil like that, we'd to the powder trick. Often times the oil will spread from the wind and it's damn near impossible to pinpoint it without the powder.

How we came about that was because of a replaced head gasket that didn't fix the oil leak. It turned out to be a porous cylinder block. We had a few of them and Kaw paid the warranty claim no problem.

It was the Kaw Hotline that turned us onto the powder trick. They don't like wasting time replacing gaskets tha aren't bad either :silly:

If the motor's not smoking, then the top end is probably in good condition.

Harbor Freight has a very inexpensice leak down tester. It's probably just as cost effective to buy that rather than to fab one up.

As for cleaning up the oxidized aluminum engine, there's a thread on making a low budget blaster. You can then use baking soda to blast the motor. You'll want to cover up your covers if they're polished and go easy around them but it should do the job and it washes right off.

You can use agricultural baking soda that you get at AGWAY. Less thatn $10 for 50lbs last I knew.

Good luck

Hey Larry, I scanned your head porting website, and I am impressed with your knowledge of these engines. It is a real benefit for you to be on the forum.
The guy I bought my Kaw from insisted that the motor had been replaced. It only has about 20k on the odometer. I personally think that my engine is like new save for the oil leaks. Now, I have had to replace the speedo and clutch cables. That may be normal if they are not lubed regularly, and may not be an indication of the miles on the chassis. You would think that a bike speedo cable would last as long as the one on a car.
It is no problem pinpointing my head gasket leak. I can let it idle after degreasing it, and the oil will appear after a few minutes. The tricky leak is the oil that appears on TOP of the top fin just ahead of the spark plug on the left side. That may be where the footpowder method may come in handy.
BTW, there is a Harbor Freight less than a mile from where I work on the same road here in Norman, OK. I will ck out the leakdown tester if you think that is a better check than a compression test, and obviously, you do.
I have noticed that the tranny almost wants to be speed-shifted. When I shift at low RPM letting off the throttle, it clunks into gear, but if I hold the throttle steady, it goes into gear smoothly. I wish they had a clutch brake on these engined like big diesel trucks do. My bike clunks into gear from neutral nastily. In case you know little about diesel trucks, they have a thingamajig on the release bearing assembly that brakes the input shaft when the clutch pedal is depressed fully.

From your description of "on top of the top fin beside the spark plug" makes me wonder if it's the cam endcaps and not the bolts. Do you have the black ones or the ones with the aluminum bit to cover up the black...my old ones used to leak really bad too.

My trany is just like yours too, you get used to the clunking.

x2

I have the aluminum caps. what is the solution? pop them out, and use silicone? do I have to remove the valve covers? Thanks

pop the valve cover off, check valve clearances while in there clean off the old gasket and pop the old cam caps out. They are not expensive from Z1E at all. Here is a link to my bikes thread on the page where everyone tells me what sealants to use...
kzrider.com/index.php?option=com_kunena&...mit=20&limitstart=80

put the new caps in (i got the black ones because the aluminum capped ones cover up the cap so you can't see if it is leaking in there or not.) Then put a new cam cover gasket and voila! I have no more leaks now, the motor actually stays clean after a ride! lol