Race report

[gravelsurfer]

Hey y’all! So last weekend was our “Condo 750” Rally. Preparations for this year included dealing with my on-going issue of too much oil getting past the “ZipTy/Toxic Racing engine breather and catch can” into the airbox and then all over the bike and me! My solution was to blank off the airbox breather hose inlet, then put a long breather hose on the catch can which ended all the way up into a second catch can on the nav tower. The second catch can is open to the atmosphere so as not to seal the system off. During pre-race testing it seemed to work perfectly.
So day 1 started at 7.25am for me, and off I go. Took me a while to find my groove in the first 90km section but I was feeling good and enjoying the ride. About half way through the second stage (138km) I noticed I had some oil around the second catch can. This was enough for me to back off and nurse it to the end of the stage so I could take a better look at it on the 1hr lunch break. We found that it had basically coughed a small amount of oil into the catch can under pressure, but seemed otherwise perfectly healthy. We wiped it down so I could keep an eye on it and went back out for the two afternoon stages. I lost a lot of time as a result of nursing it through the big 138km stage so I was further down the order than I would have liked but my one and only goal was to finish so whatever. I gave it the beans in the afternoon and it ran perfectly, no issues at all. I came into the service park around 5pm so it was a long day but I was just happy the bike was all good. Sunday morning and off we go again. I set myself the goal of passing at least 5 riders in front of me since in theory I should be quicker than my Saturday times reflected. I got to the start of the first competitive stage after a 40+km transport, only to see the most chronic blanket of low hanging dust I have ever ridden in. About 40 bikes had already set off at one minute intervals, and with zero breeze the dust just hung thick and low. They told us some of these farms hadn’t seen rain in over two years so it was extremely dry. Finally my turn to go, but the visibility was very poor so I didn’t take any risks. Despite that I somehow managed to pass three bikes in the first 50 or so km, and was feeling great, enjoying the riding and just doing my thing. The solidarity is part the attraction to Rally racing for me, you’re alone most of the time. Unfortunately at around the 74km mark the bike gave up, again! I was gutted.... I still don’t know exactly how bad the damage is but the engine locked up. About an hour and a half later and I was on the back of the recovery truck getting a ride to my crew. Bugger!!
Later that afternoon back at the bivouac it actually started but only because it had cooled down so I shut it off immediately. I have to find a good engine guy now since it’s way out of my depth, I’m hoping it may only be a top end...
I’ll let you know when I know...
The bike still won the beauty contest lol even amongst some very nice and much newer machines.... happy with that!!
cheers

[SchillerM]

I am gutted for you! Sorry to hear what happened.
Original motor? How many miles? How much of that racing?

ZipTy racing has some tricks for the bottom end for better oil flow. Not sure what shipping to US would run$$. Unfortunately they don't share the trick so not sure what another shop can do.

I don't remember all your history with the motor. Any chance the oil cooler is partial cause of oil issue? Wondering if the height over the breather causes issues? Curious how the oiling system differs from KTM 450RR.

Glad to see you are sticking with the bike and resisting any temptation to fo orange.
Matt

[gravelsurfer]

Hey Matt, thanks for the encouragement. It never ceases to amaze me how people that don’t ride just assume that failing is a reason to quit! I ain’t ready to give up yet!! This engine is the second one, the first went bang a few years ago so I replaced the entire unit with a crate motor from Speedbrain. It only has minimal hrs on it, hasn’t even had its first valve adjustment. I can’t remember exactly how many hrs and I’m not at home right now to check. I’m hopeful it just dusted the top end but I also think you might be onto something with the oil cooler. The combination of oil cooler and ZipTy breather seems to be the root of all evil for me. No one I can find had used this combo in such extreme conditions. The first two times I finished the event it was without any of the problems I have had in recent years. The breather/catch can just doesn’t seem to cope with the added oil volume when the bike is pushed to maximum. To give you an idea we do a total of 500km (300 miles) each day, in extremely hot and dusty conditions. The bikes are geared for high speeds so we’re either pushing the hard through the deep bulldust or flying down 2-3km fence lines at max throttle. Very hard on equipment.... weird things happen, stuff breaks under the strain that you would never think would. Usually around 30% of the field DNF, so I’m not alone ... just had too many lol
I’m going to keep persisting though, at least until I finish one more time. I love that bike, and I’m not giving up on her!!
As soon as we get it in pieces I’ll let y’all know what we find.
Cheers

[E-Jay]

Very sorry to hear this! Hope the problem is not to big.

[E-Jay]

A dutch guy contacted me about the zipty mod and the returnline to the pumpscreen. He wants to buy my spare, but i dont want to sell him an item i do not believe in and your experience does not give great confindence.

Could it be that the returnline sucks air from your catch can?

[Tims1572]

Quote from above: "Could it be that the return line sucks air from your catch can"?

Evert, that's what I have thought all along.

I still believe any oil content in the breather vapor coming out of the ZipTy or a DMD rocker cover breather should be vented into a baffled catch tank that helps the oil in the vapor to condense easier. Not just float around like the smoke that it is in a hollow vessel like what happens in a empty catch can. That oil once condensed should then be returned directly to the filler cap. Not to the drain plug or the rear strainer screen as a matter of convenience just to make it easier to add oil to the filler cap.

[bello650]

You're right Chris not to give up and want to finish the race. I do not know what is broken in your engine, but apart the problem of oil return I think there is something to control with the engine. As you have a free exhaust and the ambient temperature conditions are high it may be that the ideal stoichiometric mixture of 14.7 / 1 is not reached into the engine. A bad mixture can damage the exhaust valves or the piston due engine overheating. On a video of Speedbrain I saw that he put the bike on a dynamometer bench for engine tuning. Maybe you cant also check if the AFR is stil correct with the free exhaust.

https://youtu.be/2a_qjStkEhg

Cheers

[Ashley Johnson]

Tim or Evert,


Help me understand better. Would ‘sucking air’ from catch can into the strainer screen be like a ‘vacuum leak’ situation, altering the air/fuel ratio to a Lean condition? Why/How would it be different going into the filler cap? What would happen if the return line was not properly attached at filler cap, or came loose and was venting out into atmosphere?


Thanks!
Ashley

[Tims1572]

To try to answer Ashleys questions, I would assume that the oil strainer screen would under normal capped off conditions be full of pressurized oil.

Having a breather hose that 99% of the time has nothing but positive vented pressurized air and a bit of oil vapor in it connected to the strainer screens could lead to air/oil cavitation at the screen in a normally fluid sealed system of normal 36psi of oil pressure where the strainer screen cavity is doing its job under fluid pressure.
That's to say not only could the engine be sucking air into a normally closed part of the oil system but that's actually rather obvious under certain running conditions.

That's not a good scenario to me. Think about that.

On the other hand since you have a hose connected to that strainer screens oil cavity with a large void of air in it, which can be easily compressed. Who's to say that the strainer screens 36psi oil pressure doesn't easily overcome the much lower positive breather pressure and the engines pressurized oil ends up going out of the strainer caps hose fitting and making its way out into that breather hose. My opinion is that is also a given under certain running conditions.

I don't look at it as a vacuum leak situation "per say" as in a air/fuel intake system, so it would have no effect on the air/fuel ratio being lean. As Ashley has asked.

Chris still runs the Power Commander 5 system on his bike with all the bells and whistles last time I checked with him and his wife who was instrumental in helping him get the AFRs set up in the PC V tables with my help a few years back.
I believe he still uses the PC V and the full throttle AFRs settings should be closer to the 12.8 to 1 mixture settings at anything past 80% throttle opening and anything beyond 8000 rpms. These AFR settings although rich will help cool the engine with fuel during long spurts of wide open throttle. I'm sure he could tell us more about his AFR settings on that note.

Back to the The last iteration or latest/final version of the ZipTy breather tank oil recovery system returns the oil to the left side oil drain plugs cap rather than the middle caps strainer screen. Which ZipTy claimed was a change they made to return oil directly to the oils sump area using the drain plug as more of a direct path so all oil could be available for the oil pumps consumption.

This change in re-routing of the return fittings hose on their breather tanks was done first on the Husky 449 models to cleanly run the hose up under the left case out of the way as a matter of convenience.

The previous ZipTy return line set up for the breather tank recovery system was drained directly to the to the filler cap, which is no big deal since it isn't plumbed directly into an area that could be taxing to the running engines pressurized oil system or even any residual oil pressure. However the return drain back hose was connected to the right hand side oil filler cap, to some this was considered a problem because the hose looped down and was sticking straight out from the filler cap since the threaded filler cap required a straight barbed fitting. The minor complaint was, just to be able to remove the filler cap required the removal of the oil return hose itself to get the cap off to add oil.

I have an early version of the ZipTy aluminum billet cap that has a 17mm hex and the center of the cap is threaded. I use a swivel type Stainless Steel 90 degree air brake fitting on my oil filler cap and also on the drain fitting on my breather tank. This keeps the oil return hose tucked back out of the way and allows easy tool free removal of the hose with a quick flick of a finger nail and the hose can be reconnected by simply pushing it directly back into the fittings until it stops, this type fitting still swivels once installed and spins 360 degrees so the oil filler cap can still be removed from the engine cases hole to add oil..

It has never dripped a drop and it has the same length of hose on it since I installed the system back in 2013.

[E-Jay]

@Tim; im running the setup with the the returnline to the filler cap. Not with the beautifull fitting, but i have no problem's with that. I don't change oil that often....

@Ashley: I don't see a connection with the air/fuel ratio.

@ Tim: I quote: "Having a breather hose that 99% of the time has nothing but positive vented pressurized air"

What Pressure? In our setup there's the vacuum of the airbox; and in Chris' setup it vents to open air.

@gravelsurfer: The setup with the oilcooler might change the pressure in the systeem too?

[Tims1572]

Evert,
So the ZipTy racing rocker cover breathers vented gas goes to one of the upper fittings on the round Toxic Moto breather tank. The other second upper fitting goes to a length of hose attached to a second catch can mounted up high next to the Nav Tower, and its vented to atmosphere instead of being connected like it had previously been into the air box where it would have had the intake vacuum if connected, and then bottom fitting off of the breather tank goes to what ? If not the filler cap like ours is but to the center cap on the engines left side which is the rear strainer screen ? Or am I missing something ?

The Positive pressure I would be referring to would be the engines blow by, which is slightly positive pressure, Even though there is the engines intake vacuum signal when the breather line is vented to the air box, The engine's not siphoning oil out of the breather hose. So no oil would have previously ended up in Chris's air box or the second catch can for that matter if the breather didn't have some positive pressure. That engines vented blow-by vapor out of the breather has to have some positive pressure, even if it is vented to atmosphere.

[gravelsurfer]

Hey guys, firstly I agree Tim, I’m fairly certain there was cavitation taking place. The oil looked like it had been aerated!
Now when I turn the engine over by hand it gurgles out of the breather hose! I don’t know what that’s about but we don’t have the engine apart yet. I do know that it didn’t get dust past the air filter.. it’s clean.
On the first day of racing it “coughed” a small amount of oil up and out of the breather hose, which sprayed oil around as it seemed to come out under pressure. This is the extended breather hose I fitted that used to vent into the airbox. This was the only time it happened.
My plan at this stage is to get the engine rebuilt and return it to “standard” in the hope that I can make it reliable enough to finish the damn race... the breather and oil cooler just don’t seem to want to work together in harmony...
It will be interesting to see what actually broke when we get it apart. This is going to take some time as my mate/mechanic works on the other side of the country and is only home every three weeks. I don’t trust anyone else to do it so I’ll have to be patient...
Cheers
Chris

[Miken]

Hi Chris,
Definitely stick with it and share progress with forum. I'll listen and learn from the wealth of experience here for the oil system diagnosis but was curious as to when the engine seized i.e. WOT or closed throttle or somewhere in between?
My brother and I and a few mates prepped open class two strokes to run in the Finke desert race and similar local events, in the early 80s when it was bikes only. The symptoms you describe sound a bit like what we called a "nip up" which was a temporary seizing of the piston in bore. When it cooled down it unseized and depending on how bad would even start and run (not well). We had plenty of these at WOT across the group until we figured out how rich we had to run them too keep everything cool on our air cooled two strokes. With the first liquid cooled bike we ran (KX500) we could run a leaner mixture but started to see "nip ups" if the throttle was closed quickly from WOT e.g. a kangaroo or an emu decided they wanted to share the track.
As Tim mentioned above, a rich mixture will provide additional cooling for extreme conditions but when the throttle is closed suddenly or even to part throttle the additional cooling is removed. Piston speed and heat remain the same just long enough to cause a "nip up". If on tear down you see signs of the piston having seized in the bore have a look at your AFR at the throttle position where it occurred. On the tracks with few slow sections we ran the midrange rich as well even though it compromised mid range performance.
Just as another thought and something that Matt or Tim might be able to answer? I understand that we only have about a litre of oil in the sump ar rest so I wonder how much of that is in the cambox, oil cooler and lines during extended WOT running. Could aeration due a combination of low oil volume and bike movement or in an extreme case the oil pump pickup sucking air, ibe what you are seeing in the oil? Excuse my lack of knowledge with the oil pressure systems on these bikes but is the oil cooler plumbed so that oil enters from the bottom of the cooler and with a one way valve where the line exits the engine ? We run this setup in our wet sump ski boats where we have the oil to cold water heat exchanger and the filter mounted above the sump for ease of access. It prevents drain back from the cooler and lines giving an "artificially high" oil level at rest. Although not possible on our bikes, we also run crank scrapers, windage trays and one way swinging baffles in our sumps in an attempt to keep the oil pickup submerged.
Apologies if I've gone off on a tangent but new to these high performance four strokes like our G450s.
Cheers,
Mike

[Tims1572]

Miken,

No worries, I've been known to go off on a few Tangents myself. I have been drag racing for years but have sold my mid 8 second 572" Aluminum Indy Maxx Hemi powered 70' Dodge Challenger race car. I kept my street legal tubbed 4130 Chromoly 66' Plymouth with a 543" Indy wedge.

I"m all about that oil being able to feed the engine and both of these cars run a Milodon dual line full external oiling system with a full length dragster style pan, it has trap doors, swinging gates, oil control shelves and a windage tray, all to keep that precious oil around the externally mounted Milodon swivel pickup. This system feeds the pump with a pair of -12 braided Steel lines. I have had Big block Chrysler Hemi's and Wedges for over 40 years and have never ran a single one of them with a standard oil pump that actually sucks the oil up through a block mounted pickup. Every 1 of them has been fed oil from a Milodon dual line external oil system. I have made so many custom aluminum oil pans for big Chryslers that I lost count.

As for Chris's current Power Commander V tune ?
He should be running nothing less than a 13.2 to 1 AFR at idle and that stays that way and only gets fatter as RPMs climb. He also runs the PC V with the "Autotune" feature activated so that continuously looks for the preset AFRs currently set up in the Maps tables.

I myself and I believe he did the same thing as I did, is to occupy the PC V fuel table to actually give fuel to the engine at the 1750 and 1500 rpm range also which is actually below the standard idle setting of 1950 rpm with the second butterfly removed. "Dyna Jet Power Commander V" instructions tells you not to do send any fuel to the engine below the bikes idle setting but it has been set like this on my G450 since early 2013. This will keep the engine from experiencing flame outs even if you happen to stuff the front tire momentarily against a log, rock, or hole and the idle drops below the normal idle speed. You'de be surprised how well this actually works, I ride my bikes in the Arizona high desert with lots of hills covered in loose rocks. Having a flame out here on any of these hills really sucks.

[bello650]

Hi Chris,
Definitely stick with it and share progress with forum. I'll listen and learn from the wealth of experience here for the oil system diagnosis but was curious as to when the engine seized i.e. WOT or closed throttle or somewhere in between?
My brother and I and a few mates prepped open class two strokes to run in the Finke desert race and similar local events, in the early 80s when it was bikes only. The symptoms you describe sound a bit like what we called a "nip up" which was a temporary seizing of the piston in bore. When it cooled down it unseized and depending on how bad would even start and run (not well). We had plenty of these at WOT across the group until we figured out how rich we had to run them too keep everything cool on our air cooled two strokes. With the first liquid cooled bike we ran (KX500) we could run a leaner mixture but started to see "nip ups" if the throttle was closed quickly from WOT e.g. a kangaroo or an emu decided they wanted to share the track.
As Tim mentioned above, a rich mixture will provide additional cooling for extreme conditions but when the throttle is closed suddenly or even to part throttle the additional cooling is removed. Piston speed and heat remain the same just long enough to cause a "nip up". If on tear down you see signs of the piston having seized in the bore have a look at your AFR at the throttle position where it occurred. On the tracks with few slow sections we ran the midrange rich as well even though it compromised mid range performance.
Just as another thought and something that Matt or Tim might be able to answer? I understand that we only have about a litre of oil in the sump ar rest so I wonder how much of that is in the cambox, oil cooler and lines during extended WOT running. Could aeration due a combination of low oil volume and bike movement or in an extreme case the oil pump pickup sucking air, ibe what you are seeing in the oil? Excuse my lack of knowledge with the oil pressure systems on these bikes but is the oil cooler plumbed so that oil enters from the bottom of the cooler and with a one way valve where the line exits the engine ? We run this setup in our wet sump ski boats where we have the oil to cold water heat exchanger and the filter mounted above the sump for ease of access. It prevents drain back from the cooler and lines giving an "artificially high" oil level at rest. Although not possible on our bikes, we also run crank scrapers, windage trays and one way swinging baffles in our sumps in an attempt to keep the oil pickup submerged.
Apologies if I've gone off on a tangent but new to these high performance four strokes like our G450s.
Cheers,
Mike

This is the internal document released for the BMW dealer when the G450X is launched for sale in several countries. page 10 you can see the oil circuit, you see that the bottom piston is also cooled with spraying nozzle.


https://www.dropbox.com/s/exf2cn7z8c...il_en.pdf?dl=0

[gravelsurfer]

Hi all, thanks again for all your contributions!! I haven’t touched the bike since we brought it home broken. A series of injuries (nothing to do with riding) have resulted in a pretty shitty year. I’m back on the forum today because it has started to really bug me that the Beemer is still broken, I hate things not being right. It may still take me a while but im going to make a start. I’m taking the bike over to a mate next week who’s going to design a stand for supporting the bike while removing the engine. They flop around all over the place unless properly supported so I want that dealt with before I do myself another injury pulling the thing apart. I’ll post some pics of whatever we manage to come up with.
Happy to take advice on that too if anyone has a solution already.
Cheers boys