I had an incident last week where my base gasket started to leak after 28K kms after the last rebuild. I found that the gasket started to "disappear", basically in places it disintegrated and in other areas it was brittle (OEM gasket was used). The head was re-tensioned after 1000kms.
I had a similar incident with my Z1R where the base gasket fell to pieces, I'll take a guess here but it appears that the newer gaskets don't have asbestos and basically can't handle the heat too well.
After a quick email to Randy, I found out he uses the steel XJR1200/1300 for the same reason - (Again what would we do without Randy's Knowledge)
Maybe its just me but I couldn't find similar topics so I posted mine to make people aware of this problem.
(http://i1297.photobucket.com/albums/ag34/Bozo36/P1010492_zpsbedc014d.jpg) (http://s1297.photobucket.com/user/Bozo36/media/P1010492_zpsbedc014d.jpg.html)
John,
I think I saw an order come through for you but I don't recall a base gasket. Did you find one local?
Randy - RPM
wow...thats nasty...has to be some cheap azz material !
Quote from: turbocamino on July 01, 2014, 06:04:37 PM
wow...thats nasty...has to be some cheap azz material !
No this was a genuine Yamaha gasket, Randy apparently has seen this before so its not uncommon.
Quote from: turbocamino on July 01, 2014, 06:04:37 PM
wow...thats nasty...has to be some cheap azz material !
The same stuff you had on your clutch cover...
Randy - RPM
Quote from: Bozo on June 29, 2014, 08:31:57 PM
I had an incident last week where my base gasket started to leak after 28K kms after the last rebuild. I found that the gasket started to "disappear", basically in places it disintegrated and in other areas it was brittle (OEM gasket was used). The head was re-tensioned after 1000kms.
Maybe its just me but I couldn't find similar topics so I posted mine to make people aware of this problem.
I have my original engine in bits for the same reason, not sure what the mileage was but probably a bit more than that. It was a Wiseco supplied gasket (came with the 1219 kit) and literally blew out in a couple of spots while on a trip, enough to get oil all over my left boot which made for some terrible gear changes.
Noel
What blows this base gasket out?
Crankcase pressure? If so, then can you take any steps to relieve the pressure? Additional venting, etc?
Pat,
The pressure results from having to move air under the piston. The piston is moving fast and that air has to go somewhere. If it doesn't move fast enough to the cylinder(s) moving in the opposite direction then pressure will build. Manufacturers have tried to relieve this by boring holes in the side of the cylinders (near the bottom where the rings never get) to aid the airflow between cylinders, but there's only so much they can do. The rest is physics.
Thanks Hooligan, I vaguely recall a modification where additional holes were drilled for this purpose (air balance) but my memory is co-mingled between the Miata's BP1.8 and our FJ engines.
Is there anyway this can be done on the FJ?
That gasket failed for no other reason than substandard gasket material combined with expansion & contraction of the case & barrel.
This was a problem addressed by Yamaha a long time ago when they went to the current steel coated base gasket.
Crankcase pressure, not in a normal operating FJ, unless the rings are worn out. If crankcase pressure was an issue, Yamaha would have done somethin different.
Randy - RPM
Quote from: ribbert on July 02, 2014, 09:46:24 AM
I have my original engine in bits for the same reason, not sure what the mileage was but probably a bit more than that. It was a Wiseco supplied gasket (came with the 1219 kit) and literally blew out in a couple of spots while on a trip, enough to get oil all over my left boot which made for some terrible gear changes.
Noel
Noel, how many kms did you do before this problem occurred? I have the 1219 kit in my '85 and have done approx 30,000kms, so hopefully I don't encounter the same situation. Pete. :unknown:
Quote from: FJ_Hooligan on July 02, 2014, 12:45:07 PM
Pat,
The pressure results from having to move air under the piston. The piston is moving fast and that air has to go somewhere. If it doesn't move fast enough to the cylinder(s) moving in the opposite direction then pressure will build. Manufacturers have tried to relieve this by boring holes in the side of the cylinders (near the bottom where the rings never get) to aid the airflow between cylinders, but there's only so much they can do. The rest is physics.
I don't understand this at all.
The cylinder protrudes well beyond the casing into the crankcase, the base gasket is not subjected directly to this pressure, only general crankcase pressure.
The cylinder already has a hole to relieve the pressure from the descending piston, a 3" hole directly under it. How can the pressure build when there is nothing to restrict it.
The bottom of the cylinder is open to the crankcase with no restriction, the pressure has plenty of places to go and the FJ is a short stroke engine anyway.
If you've got a 3" hole directly under the piston I can't see how small holes around the base of the cylinder are going to achieve much in terms of expelling air from one cylinder and drawing it into another, unless you're talking extreme performance engines where every 000001% helps.
I wasn't aware manufacturers considered this a problem on production engines.
Then again, possibly I'm just out of the loop with what's going on.
Noel
Quote from: oldktmdude on July 03, 2014, 07:40:04 AM
Quote from: ribbert on July 02, 2014, 09:46:24 AM
I have my original engine in bits for the same reason, not sure what the mileage was but probably a bit more than that. It was a Wiseco supplied gasket (came with the 1219 kit) and literally blew out in a couple of spots while on a trip, enough to get oil all over my left boot which made for some terrible gear changes.
Noel
Noel, how many kms did you do before this problem occurred? I have the 1219 kit in my '85 and have done approx 30,000kms, so hopefully I don't encounter the same situation. Pete. :unknown:
I don't know Pete, I don't keep records of anything for the bike, but it was probably about 50 or 60,000 km's.
Interestingly, it failed 600km's into a ride literally the day after I removed the crankcase vent into the air box and replaced it with a small filter. Not saying this caused it but I do suspect it brought it on.
In my opinion, replacing the original configuration, which sucks air from the crankcase, with a filter that creates a restriction (not much though) is going to raise crankcase pressure.
Not that this is any reason not to fit unipods, the gaskets were dodgy anyway, but the previously dry, and never touched motor currently in my bike, has become increasingly weepy around the base gasket too.
Engines since the 30's have always had some sort of assisted venting. Many will remember the old "draught tubes" and mesh filled oil filler caps on cars. The length and angle of the tube was by design to catch the airflow under the car and suck the fumes out.
Randy would know better than me, but I'm not overly confident in Wiseco's ongoing commitment to supplying low volume items, I'd get a set of rings and a head gasket (not very expensive) and stick them on the shelf in case you need them one day, and if you don't, and they become unavailable, you can double or treble your money.
Noel
I agree Noel. The negative pressure inside the airbox is an definite advantage for scavenging crankcase pressure.
That's the reason pro stock drag bikes have (several) vacuum pumps.
I looked at my UniPods to see if there were a way I could pipe in the crankcase vent hose but there was no room that I could see on the Uni's rubber mounting base.
After a long hot ride, stopping at a signal and smelling the blow by coming off the crankcase vent is annoying
Quote from: Pat Conlon on July 03, 2014, 12:11:31 PM
After a long hot ride, stopping at a signal and smelling the blow by coming off the crankcase vent is annoying
Just pretend that the smell is positive ions.... Ride on my friends....
Quote from: Pat Conlon on July 03, 2014, 12:11:31 PM
I agree Noel. The negative pressure inside the airbox is an definite advantage for scavenging crankcase pressure.
That's the reason pro stock drag bikes have (several) vacuum pumps.
I looked at my UniPods to see if there were a way I could pipe in the crankcase vent hose but there was no room that I could see on the Uni's rubber mounting base.
After a long hot ride, stopping at a signal and smelling the blow by coming off the crankcase vent is annoying
What if you made a vacuum manifold coming off of all the nipples on the intakes? The ports we hook up the sync gages. Parker/ rancor company makes vacuum breakers I believe as small as 3/8in. Our crankcase filter we install would attach to the top of the vacuum breaker. Huh...second thought, probably a bad idea to equalize vacuum on intake side of carb. Should be on filter side of carb
Scott
Yup, need to be on the filter side of the throttle butterfly. Downwind=manifold vacuum, NG. I remember looking for a place to install a hose barbed fitting and there was no room. Maybe on the next-gen of Uni-pods ...
I guess nobody got/liked the Hunt for Red October reference, huh?
I got it, being ex bubblehead...couldn't find the "like" button
S
Did you use any type of sealant on that gasket (Hylomar etc).? I have seen Cometic fiber base gaskets "push out" when gasket sealer is applied or if they become saturated with oil..
It looks like the oring lifted as well in that pic....that's odd and interesting. Fiber gaskets suck in general IMO....MLS, Viton coated steel, foam/steel core or orings are what I prefer. Copper seals well against everything but oil.
I wouldn't bother with cylinder head retorquing either.
The interesting way to create an artifical vacuum is to use the exhaust, not the intake. A venturi tube in the collector at the appropriate angle with a fancy high-temp, high-speed PCV valve can be used to evacuate the crankcase pressure very effectively.
I've never seen an actual pump type setup on a drag motorcycle. Occasionally on cars, though. Seems that the weight is excessive on a motorbike.
Years ago pro stock were using vacuum units and than started stacking them. They were then regualted to one unit, Gast still sells them though I don't know how they are used with the Vtwins (if they are used). I don't the exhaust units actually pulled much vacuum as there was always reversion etc.
That's why you ran the flapper valve, to stop the reversion.
Interesting replies, I agree the vacuum from the intake would help, but I still believe there is a problem with the gasket material. It turns into mush, remember I had no sealant it was an OEM gasket, std cams, Wiseco 1200, slightly higher compression etc. 28K kms since rebuild compressions even from 160 to 170psi.
The couple of riders from the KZowners forum had the same problem as I did with my Z1-R. I do know it was a quality gasket but my log doesn't state what type (45K kms)
I've had the same problem with fumes at a standstill when the motor is hot, currently trying this set up, only been running it a month or so, gets rid of the fumes and doesn't seem to have any adverse effect on carburration, but I read some posts that say it's better to vent to air than recycle through the carbs, so I'm not sure about carbon build up etc. long term, and then again some say the oil helps lubricate the valve stems. Does anyone know truth in all this?
Anyway I used a Chammy container, don't know if that's what you call it elsewhere, the larger tube comes from the crankcase breather and each carb should more or less get an equal dose, you can see the condensation in the tubes. I made them all push fits so there is nothing to come loose and end up in the intakes. Not sure if some sort of filter would be a good idea inside the container, but so far the is no build up of oil residue etc. in the bottom of the container. The alloy checker-plate has nothing to do with it, that's just where I keep my tool kit.
Cheers, John
Thanks John, that's a nice setup.....yea, I'd love to do something like that with my UniPod foam filters, but no way I'm going back to a paper filter. I have not had good results from K&N oiled paper filters, except in my Miata.
No room for nipples on the rubber base material on the Uni's so that leaves the foam filter material itself.
Some threaded hose nipples with washers might work on the foam, but I doubt it, the hose stress on the foam material will probably cause a failure.
Inside the UniPods there is a stainless spring that holds the shape of the intake chamber, preventing the foam from collapsing from vacuum.... Perhaps there is a way that spring can be used to support the vent hose?
I'm working on it.....
Re: Lubrication...I suspect the oil vapor coming off the crankcase won't be any lubrication benefits since it would the thoroughly diluted with the fuel/air mixture from the carbs.
Cheers Pat
Hi Pat, I'll probably tidy it up a bit once I'm happy it works ok it looks a bit cheap and nasty at the moment but it was just bits and pieces I had lying around. I did try it first with the foam uni pods, by making a hole through the back between the two outlets but there is a piece of foam between the two springs that gets in the way and I managed to tear a hole in the outer foam cover mucking around with it but there is a possibility there, I may play around with it a bit more, just need to attach a right angle fitting in there between the outlets run two hoses into a Y piece and onto the crankcase breather, it would be a lot neater set up and hidden under the pods.
Cheers, John
I am going to let my inner voice of reason speak here...
I believe that is a bad idea.
On the factory air box the breather hose is venting out of the direct suction of the carb throats. The air box connection is under the carbs so the oil & water contaminants can drop & drain before being sucked into the engine.
(http://i1215.photobucket.com/albums/cc517/racerrad8/bc99e44c-9a7f-464a-afeb-b78b8394d62b_zpsc182f57a.jpg~original) (http://s1215.photobucket.com/user/racerrad8/media/bc99e44c-9a7f-464a-afeb-b78b8394d62b_zpsc182f57a.jpg.html)
The slides are not very happy when they get anything on them as they then start sticking. The water vapors you see in the hose will also be in the throat of the carb and cause corrosion of the raw aluminum carb bodies and oil vapor will allow crud to build up and cause slide problems over time.
And finally, the amount of suction you have at the pod air filter is so much greater that you no longer have a crankcase vent, but a PCV system. Sure, the air box is considered a PCV system as well but it is using the totality of the vacuum from the carbs at a 180* and greater distance from the vacuum source.
Randy - RPM
Quote from: JMR on July 04, 2014, 10:41:29 AM
Did you use any type of sealant on that gasket (Hylomar etc).? I have seen Cometic fiber base gaskets "push out" when gasket sealer is applied or if they become saturated with oil..
It looks like the oring lifted as well in that pic....that's odd and interesting. Fiber gaskets suck in general IMO....MLS, Viton coated steel, foam/steel core or orings are what I prefer. Copper seals well against everything but oil.
I wouldn't bother with cylinder head retorquing either.
Sorry haven't replied earlier, I'm still on a job away from home. As I stated the gasket was installed dry, the O'ring was brittle? it also was put on with a silicon lubricant (Randy stated that the O'ring is not necessary). My motor ran very hot when I had the Megacycle cams especially in the Oz summer in peak hour traffic (vapour came out of the oil breather when stopped at lights) so I guess that cooked the O'rings as for the gasket???. Now I have XJR1300 base (steel) gasket and the standard steel FJ gasket, both lightly coated with "Copper coat" just to be sure.
Quote from: racerrad8 on July 09, 2014, 11:27:33 AM
I am going to let my inner voice of reason speak here...
I believe that is a bad idea.
Randy - RPM
Thanks Randy, maybe time for a bit of a re-think then, how about some sort of filter between the tube from the crankcase breather and the the tubes to the carbs? and a drain to get rid of condensation.
Cheers, John.
Actually I was thinking along the lines of a sealed catch can (not vented) This would allow the oil to condensate and collect before routing thru the carbs. Fill the can with scrub able stainless steel to help separate the oil out of the blow by vapor. Have a drain at the bottom of the can where you can periodically drain off the accumulated oil.
We use this set up in turbo Miata's all the time. It works well. Not exactly CARB approved 'thou...
I'm mean, jeeze, we got all this room now that the airbox is removed. We can come up with something.
I'm tired of a stinky bike at stop lights.
Quote from: Pat Conlon on July 09, 2014, 11:31:16 PM
Actually I was thinking along the lines of a sealed catch can (not vented) This would allow the oil to condensate and collect before routing thru the carbs. Fill the can with scrub able stainless steel to help separate the oil out of the blow by vapor. Have a drain at the bottom of the can where you can periodically drain off the accumulated oil.
We use this set up in turbo Miata's all the time. It works well. Not exactly CARB approved 'thou...
I'm mean, jeeze, we got all this room now that the airbox is removed. We can come up with something.
I'm tired of a stinky bike at stop lights.
Sure that is what you use on the Miata, but you do not put that contaminated vapor in front of the throttle plate do you? If yes, then that would mean the turbo pressure would be pressuring the breather tank too if that was the case.
Maybe we need to re-install the air box which will do everything that needs to be done.
Randy - RPM
But I love the induction sound and ease of maintenance with the pods, never happy are we Randy, that's the problem once you catch the 'moditus' virus, but still it's good for business mate.
John.
Noooooo not the air box.....perhaps that smell isn't so bad after all....
Yes, on the turbos the crankcase vapors are pulled in between the filter and the compressor intake, thru the compressor, thru the throttle plate into the engine.
Folks also run the vented catch cans but they have noticed that the engines seem to run better with a slight negative pressure in the valve galley.
Quote from: racerrad8 on July 10, 2014, 01:11:36 PM
Quote from: Pat Conlon on July 09, 2014, 11:31:16 PM
I'm tired of a stinky bike at stop lights.
Maybe we need to re-install the air box which will do everything that needs to be done.
I had the same "stinky bike" and even had some oil vapor coming out of the vents beside the carbs... I tried moving the breather back to the tail area, but that just relocated the stink/vapor. I moved it back to under the pods, and this time made it fit right under the center two (I have 4 individual Uni filters) as close as possible to the carb intakes hoping the blowby would get sucked in through the pods mostly...
IT WORKED! No more stink or smoke, just a happy FJ breathing it's own fumes... Might give this a try Pat.
Frank
Quote from: Flynt on July 11, 2014, 10:35:53 AM
Quote from: racerrad8 on July 10, 2014, 01:11:36 PM
Quote from: Pat Conlon on July 09, 2014, 11:31:16 PM
I'm tired of a stinky bike at stop lights.
Maybe we need to re-install the air box which will do everything that needs to be done.
I had the same "stinky bike" and even had some oil vapor coming out of the vents beside the carbs... I tried moving the breather back to the tail area, but that just relocated the stink/vapor. I moved it back to under the pods, and this time made it fit right under the center two (I have 4 individual Uni filters) as close as possible to the carb intakes hoping the blowby would get sucked in through the pods mostly...
IT WORKED! No more stink or smoke, just a happy FJ breathing it's own fumes... Might give this a try Pat.
Frank
I did the same thing, zip tied the breather so it was almost touching the uni-pod...no more fumes and with the breather hose almost vertical I would imagine any condensed oil vapor would easily drain back to crankcase.
Scott
That's the way I set mine up also. It is back about 2 inchs from the pods up high, tied to the frame cross brace. Never noticed a problem.
George
Ok! Thanks guys, I'll give it a go..... :good2:
I will give it a go as well.
John
Me too! Hate that drifting smell at the lights.
I knew I read this recently, but I have seen it repeatedly in the general motorcycle literature for several years now.
In the April issue of Sport Rider from their test of the 2014 Kawasaki Ninja 1000, they mention:
"Windows between the cylinder cavities in the crankcase reduce pumping losses at high RPM..."
It may not have been the cause for the original base gasket failure, but it is an issue that engine manufacturers are addressing.
Quote from: ribbert on July 03, 2014, 09:05:22 AM
Quote from: FJ_Hooligan on July 02, 2014, 12:45:07 PM
Pat,
The pressure results from having to move air under the piston. The piston is moving fast and that air has to go somewhere. If it doesn't move fast enough to the cylinder(s) moving in the opposite direction then pressure will build. Manufacturers have tried to relieve this by boring holes in the side of the cylinders (near the bottom where the rings never get) to aid the airflow between cylinders, but there's only so much they can do. The rest is physics.
I don't understand this at all.
The cylinder protrudes well beyond the casing into the crankcase, the base gasket is not subjected directly to this pressure, only general crankcase pressure.
The cylinder already has a hole to relieve the pressure from the descending piston, a 3" hole directly under it. How can the pressure build when there is nothing to restrict it.
The bottom of the cylinder is open to the crankcase with no restriction, the pressure has plenty of places to go and the FJ is a short stroke engine anyway.
If you've got a 3" hole directly under the piston I can't see how small holes around the base of the cylinder are going to achieve much in terms of expelling air from one cylinder and drawing it into another, unless you're talking extreme performance engines where every 000001% helps.
I wasn't aware manufacturers considered this a problem on production engines.
Then again, possibly I'm just out of the loop with what's going on.
Noel
Quote from: FJ_Hooligan on July 30, 2014, 05:49:58 PM
"Windows between the cylinder cavities in the crankcase reduce pumping losses at high RPM..."
Which Yamaha addressed already beginning in 1984...
You can see the "windows" or pressure differential ports between the two outer cylinder cavity webs.
Randy - RPM
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(http://i1215.photobucket.com/albums/cc517/racerrad8/002_zpsb28526a4.jpg~original) (http://s1215.photobucket.com/user/racerrad8/media/002_zpsb28526a4.jpg.html)