Leak down Test

Uncle Buck,

Spring came a good moth early this year. There is still snow on the ground, but I don't like riding on hard spring snow. Plus work has been getting busy. Have to make hay while the sun is shining.

Yes, I get some vapors from the vent line. I too hav a filter in the end of mine. I have not noticed large amounts of oil,, but there is residue in the area around the vent.

I wonder where we could find one of the new crankcase vents and/or diagrams of them. Is there a service manual available yet?
 
Probably not. They usually come out in August and then it is Sept. before you can gat one. I am working on some sort of a solution to reducing the case pressure.
 
As far as the compression of the engine with the turbo, I now have about 2700 mi on it and it has not changed. No oil consumption at all. I use regular fossil oil(Yama lube)The turbo was installed right from a new engine. My crank breather runs out to beneth the inter cooler, as per MC spec. Its just a hose with no filter at all. I installed the rear mounted MC unit and it has 10lb boost, std setting from MC. Have not installed a boost regulator yet. I would like to get one and be able to adjust on the trail. I read the post today and I am curious as to why some people have that problem( turboed or not ) and some don't. There has to be some common denominator here. I have had Yamaha bikes for years and can tell you that the motors they build have gone through alot of abuse from me and my sons over the years and never had any issues like this. Anyways hope you guys find out what the problem is and if I here anything I will certainlly let you know. I know a lot of Yami motorheads around here and I will run this by them and see what they say.
 
Have there been any developments on this subject?

Uncle Buck, did you ever do a leak down on you sled? Did the Seafoam seem to make any diferrence?

I noticed oil consumption towards the end of last season. On normal mountain rides I could put on a few hundred miles over several days and not seem to use any oil. However, I took a trail ride that was about 60 miles and required constant 8,000 to 10,000 rpms and then about 30 miles of off trail riding. That trip I used just short of a quart of oil. It seems that the sustained high RPM use causes oil consumption.

There is something else that chnaged near the time I started usign oil. I have a Bender turbo and I switched from their remote oil tank to the engine oil system around the same time that these oil issues started. Is it possible that we are pushing oil past our seals because of the high pressure produced by the motor?

Of course this would not explain why some NON turbo people are having problems.
 
Personally I would like to know how many people, that are running turbos or not, who have a oil burnig isssues in there sled, are using synthetic. I think that is the common denominator.
 
I was running synthetic and switched back to Yamalube in an effort to eliminate that as a possibility. I still used oil, as a matter of fact the trip I described above was made using yamalube.
 
I have done nothing with my sled yet. I haven't been motivated, but I am now getting ready to start. I will try to do a leak down before I tear the motor down. I am putting the low compression pistons, so I won't have to make it an annual event. I am also looking into different crankcase evac systems to help relief the pressure.
I started the season using Amsoil but after 300 miles the oil consumption was so bad I switched back to regular oil. By that time it was too late. I ended up using a quart every 200 miles. I can't say if the Seafoam worked becasue I only got about 150 miles with it before the snow was gone. I am sure it didn't hurt, but I think the problem is bigger than a carbon build up. The Seafoam definitely turned my oil black.
Now, Phil has my interest up with that Garrett turbo. More money :o| ;)!
 
Uncle Buck,

Call me. PM me if you need the number.

I am thinking that the bulk of the problem is the lack of a good EVAC. I too am looking at ways to add more venting. Jason has a kit coming out before long, but I don't really have any details.

A person could add something like this: http://go.mrgasket.com/ProductDetails.a ... selection=
or this: http://www.jegs.com/cgi-bin/ncommerce3/ ... rmenbr=361

I think there is another contributing factor, at least in my case, and that is to much oil pressure going from the engine to the turbo.

Go tear that motor down tonight so You can tell me what's going on in there. ;)!
 
IF Bender Did there homework and I believe they did the Turbo should be spec'd for the engines operating oil pressure.

When we startd talking to Turbonetic about a Turbo charger they had us supply them with different things that included ide oil pressure and full stroke oil pressure. Like I said I'm sure Bender did the same thing.
 
Here is the story as I know it.

They did do there homework, the problem seems to be that the specs given to them are not acurate. I may be off on the exact numbers, but I'm in the ballpark. The turbo was supposed to handle something in the neighborhood of 75-80psi. When Terry tested he never went over 68psi. The problem was after a few hundred miles seals were blowing out causing a lot of oil to go into the airbox. Terry came up with a restrictor and that cured the problem for most people. Some, like me, are still getting oil in their airbox. I am getting dramatically less, but there is still some. A smaller restrictor seems to have cured this problem all together for the few that have tried it. I will say that Terry has been awesome about standing behind his product. There were a good number of turbos that lost there seals and to my knowledge Terry replaced all of them.

The other issue I am trying to address is the burning of oil. I beleive that to be caused by high pressures in the crankcase. As you know this does not seem to be exclusive to turbo owners, however, I think the turbo (or maybe the removal of the vent from a vacuum source) is making the issue worse. I'm hoping that no serious/permanent damage has been done and that if I add venting the problem will go away.

Your thoughts?
 
The Turbo should and must be able to handle the oil pressure. I would make a change there and correct it. However I don't think that is why your buring oil. Until you blow the seal in the turbo the oil can't pass by the bearing.

I'm guessing you have a crank case pressure issue. I beleive it is an issue on a stocker as well. Generally Crank cases are vented at the highest part of the motor and this isn't the case on the RX-1. Maybe all bikes are this way. My point being You need more venting even on a stocker. the Turbo only adds to this problem. The kit we offer will increase crank case venting and allow all oil passed throught the vents back into the motor.


Like I said I feel this need on all RX-1's. Isn't it funny Yamaha has created a check valve inline on the new 120 motor. i'm guessing it only passes air.
 
It seems we agree.....

Now just get me that kit! :lol: :lol:
 
FYI, here's what I did at the end of the season using seafoam. I removed the spark plugs and raised the back of the sled so the rear bumper was approx. 5 feet off the ground. Since the motor is angled backwards in the sled approximately 30 degrees, raising the sled this amount will make the top if the piston parallel with the ground. This would insure that the seafoam would contact the rings all the way around. I then put maybe ½ ounce or so of seafoam in each spark plug hole and turned the motor over by hand. I let the seafoam work for a couple of days occasionally turning the motor ½ a turn. After 2 days I used the starter to crank the motor over for 5 seconds and then lowered the sled to the floor and replaced the spark plugs. The sled fired right up with maybe a slight puff of smoke. After it warmed up it sure seems to idle smoother and I even think it starts easier. My exhaust tips seem to stay cleaner also. Oh, by the way, I removed the skis before I lifted the back, the front bumper will almost touch the ground this way if you lift it high enough.
 
I think Seafoam is a bandaid approach and will only clean the carbon out. This will not solve the crankcase pressure issue that exists in both stock and turbo motors. EVAC, EVAC, EVAC. I also think the lower compression pistons will helpand MORE BOOST is a plus!
Ray, I have your number somewhere. I'll give you a call.
 
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