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Old 07-28-2013, 07:50 AM   #16
lineaway
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By the way, someone on trials central posted about a bad batch of mains in the new Raga`s. A handful in the UK. were having issues.
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Old 07-29-2013, 08:11 AM   #17
motobene OP
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Quote:
Originally Posted by lineaway View Post
By the way, someone on trials central posted about a bad batch of mains in the new Raga`s. A handful in the UK. were having issues.
The post was by a young man who said: just to let anyone know - if your thinking off buying a 2013 factory rep raga DONT! they have come with a dodgy batch of main bearings! 5-6 have been recalled in the uk!

...to which was replied to by an older person: ...be careful when throwing around aspersions like that. Trials in a small market and you can cost the importers a whole heap of money and find yourself in big trouble. I appreciate you mean well but, unless you are absolutely 100% sure of your facts, it is best to keep them to yourself and not spread them around the internet.

I plan to be into two motors in a couple of days. I'll certainly be looking at the mains and checking for radial play on the more vibrating `11 Raga. Presently I ascribe the problem to an out-of-balance crank.

Here is a Nasa document on roller bearings that's interesting:

http://ntrs.nasa.gov/archive/nasa/ca...2012008568.pdf

motobene screwed with this post 07-29-2013 at 08:19 AM
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Old 07-29-2013, 08:54 AM   #18
lineaway
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Oh I realize who said it. But these problems even when known are kept pretty quiet. As an individual, they make you feel like it is an isolated case. It has happened to all the factories thru the years.
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Old 07-30-2013, 03:20 AM   #19
motobene OP
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Originally Posted by lineaway View Post
Oh I realize who said it. But these problems even when known are kept pretty quiet. As an individual, they make you feel like it is an isolated case. It has happened to all the factories thru the years.
I was many years designing, testing and selling lower limb prosthetic medical products internationally. You can test all sorts of ways up to production, and yet there will be some surprises... some learning experiences in the field and things are discovered when product is used in unimaginable ways. Or changes in the supply stream when someone figured we'd save money by changing a key vendor, and those parts start failing.
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Old 07-30-2013, 08:41 AM   #20
laser17
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Quote:
Originally Posted by motobene View Post
The post was by a young man who said: just to let anyone know - if your thinking off buying a 2013 factory rep raga DONT! they have come with a dodgy batch of main bearings! 5-6 have been recalled in the uk!

...to which was replied to by an older person: ...be careful when throwing around aspersions like that. Trials in a small market and you can cost the importers a whole heap of money and find yourself in big trouble. I appreciate you mean well but, unless you are absolutely 100% sure of your facts, it is best to keep them to yourself and not spread them around the internet.

I plan to be into two motors in a couple of days. I'll certainly be looking at the mains and checking for radial play on the more vibrating `11 Raga. Presently I ascribe the problem to an out-of-balance crank.

Here is a Nasa document on roller bearings that's interesting:

http://ntrs.nasa.gov/archive/nasa/ca...2012008568.pdf
Thats a good read - thanks!
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Old 07-30-2013, 09:58 AM   #21
Twin-shocker
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One of the main reasons main bearing failure seems much more common nowadays than it was maybe 20 years ago, is I think due to modern Efuels, and the almost universal use of dual purpose 2T oils, which are also suited to autolube use.

Efuels in themselves absorb water, and where bikes using Efuels are stored for any length of time, there may well be problems with carb jets and drillings getting blocked, and in severe cases leading to the need for a new carb. Efuels also tend to degrade nitrile crank seals much quicker, and its a good idea to fit viton seals if these are available when it comes to rebuilding a motor.

The dual purpose 2T oils are necessarily very thin so they can be used in autolube systems, which is less than ideal for pre-mix bikes, as the oils are thinned with kerosene or white spirit at up to 30% by volume, that means mix ratios must be increased to provide the same lubrication performance and corrosion protection as a pre-mix only full synthetic competition oil.

However many users mix the dual purpose oils at the same ratio which would be appropriate for a proper pre-mix only product. As trials motors are very low stress, this isnt something thats likely to compromise lubrication. However due to the very thin dual purpose oils not providing as good film coverage as much lower viscosity pre mix products, to protect engine internals when bikes are not being used, this in combination with cleaning methods which often involve some amount of water finding its way into the motor, and you have a recipe for increased chances of corrosion, which will often result in early main bearing failure.

The way to ensure the best possible main bearing life is to use a full synthetic pre-mix only oil, such as Castrol XR77 or Motul M800, mixed at 70:1 for air cooled and 80-100:1 for water cooled, and be careful to prevent water getting into motors when bikes are cleaned, and always run motors for at least 10 minutes after cleaning has been carried out.

Replacing main bearings isnt an expensive job, but it is something that can be avoided in many cases, if the simple advice given above is followed.
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Old 07-31-2013, 07:58 AM   #22
motobene OP
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Quote:
Originally Posted by Twin-shocker View Post
One of the main reasons main bearing failure seems much more common nowadays than it was maybe 20 years ago, is I think due to modern Efuels, and the almost universal use of dual purpose 2T oils, which are also suited to autolube use.

Efuels in themselves absorb water, and where bikes using Efuels are stored for any length of time, there may well be problems with carb jets and drillings getting blocked, and in severe cases leading to the need for a new carb. Efuels also tend to degrade nitrile crank seals much quicker, and its a good idea to fit viton seals if these are available when it comes to rebuilding a motor.

The dual purpose 2T oils are necessarily very thin so they can be used in autolube systems, which is less than ideal for pre-mix bikes, as the oils are thinned with kerosene or white spirit at up to 30% by volume, that means mix ratios must be increased to provide the same lubrication performance and corrosion protection as a pre-mix only full synthetic competition oil.

However many users mix the dual purpose oils at the same ratio which would be appropriate for a proper pre-mix only product. As trials motors are very low stress, this isnt something thats likely to compromise lubrication. However due to the very thin dual purpose oils not providing as good film coverage as much lower viscosity pre mix products, to protect engine internals when bikes are not being used, this in combination with cleaning methods which often involve some amount of water finding its way into the motor, and you have a recipe for increased chances of corrosion, which will often result in early main bearing failure.

The way to ensure the best possible main bearing life is to use a full synthetic pre-mix only oil, such as Castrol XR77 or Motul M800, mixed at 70:1 for air cooled and 80-100:1 for water cooled, and be careful to prevent water getting into motors when bikes are cleaned, and always run motors for at least 10 minutes after cleaning has been carried out.

Replacing main bearings isnt an expensive job, but it is something that can be avoided in many cases, if the simple advice given above is followed.
Interesting contribution, Twin-shocker.

I personally don't sweat E10. Could offer a long technical and experience explanation, but suffice to say that water up to saturation in E10 passes through harmlessly.

As for external water, I deal with that with real foam filter oil (Maxima FFT), soaked and wrung out. External water beads up and runs around the filter, preventing muddy water (water + dust) from passing through the engine.

Checked my semi-synthetic Lucas 2 stroke oil. It doesn't specify, just says for all 2 strokes and up to 50:1 (but we know better for trials bikes). I wonder if a little dilution for injectors before gobs of dilution (80:1) is a big deal? Bearings are lubed adequately by a super thin film and boundary layer. A very little is apparently enough, and any excess gets flattened to very little by the balls running over the film at high velocity.
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Old 07-31-2013, 10:16 AM   #23
Twin-shocker
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In many cases water will find its way into uncovered air boxes, and into unplugged exhausts during the cleaning process. Have noticed its not that common for riders to always run bikes after cleaning, so I get the feeling that very thin autolube oils, combined with excess moisture which isnt removed by running motors, is very possibly a reason for the many instances of main bearing failure, that seem so common nowadays?

I dont have any technical data on Efuel, but there are certainly issues such as phase separation, and carbs being destroyed if its not drained before bikes are stored. All in all if at all possible, probably a very good idea not to use Efuel if an alternative is available at reasonable cost? Bikes running on Efuel, are also far more sensitive to changes in atmospheric pressure, and there is sometimes a need to adjust pilot mixture as the conditions change.

Using a proper pre-mix only oil, and running bikes after cleaning isnt something that costs a lot in money terms, but I think is well worth doing, as is anything that might extend engine life at low cost. Earlier this year I stripped a motor, which had obviously got water into it during the cleaning process, and the resultant corrosion meant the cylinder needed boring.
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Old 08-01-2013, 08:39 AM   #24
motobene OP
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Quote:
Originally Posted by Twin-shocker View Post
In many cases water will find its way into uncovered air boxes, and into unplugged exhausts during the cleaning process. Have noticed its not that common for riders to always run bikes after cleaning, so I get the feeling that very thin autolube oils, combined with excess moisture which isnt removed by running motors, is very possibly a reason for the many instances of main bearing failure, that seem so common nowadays?

I dont have any technical data on Efuel, but there are certainly issues such as phase separation, and carbs being destroyed if its not drained before bikes are stored. All in all if at all possible, probably a very good idea not to use Efuel if an alternative is available at reasonable cost? Bikes running on Efuel, are also far more sensitive to changes in atmospheric pressure, and there is sometimes a need to adjust pilot mixture as the conditions change.

Using a proper pre-mix only oil, and running bikes after cleaning isnt something that costs a lot in money terms, but I think is well worth doing, as is anything that might extend engine life at low cost. Earlier this year I stripped a motor, which had obviously got water into it during the cleaning process, and the resultant corrosion meant the cylinder needed boring.
Agree that bikes should be run after cleaning. Always a good idea. I'm not bashful with a pressure washer. There's always one set up here at the ranch ready to go except in winter, then I have to pull it out of storage.

Are main bearing failures that frequent? There are very infrequent here. I remember 1 in 40 years, on a 1985 KTM 350 that used a roller bearing on one side. You are much wetter in UK. Perhaps a lot of riders suck in water through under-oiled filters or just plain take a plunge into deep streams, stall out, then park their bikes for weeks
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Old 08-02-2013, 12:40 AM   #25
Twin-shocker
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Here in the UK main bearing failure in very common. Large trials dealer not far from me was doing 4 a week, when the factories were fitting shield type main bearings, which I think would increase the chances of damage due to condensation/corrosion.

Get the feeling that moisture and lack of corrosion protection from inappropriate 2T oils is at work here, but maybe Efuel is also playing a part as well?

Problem with Efuel is that there hasnt been any sort of proper investigation into the negatives, only really greenwash and propaganda from the manufacturers, so we will probably never know if Efuel is bad for 2T bikes or not.
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Old 08-03-2013, 07:50 AM   #26
motobene OP
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Quote:
Originally Posted by Twin-shocker View Post
Here in the UK main bearing failure in very common. Large trials dealer not far from me was doing 4 a week, when the factories were fitting shield type main bearings, which I think would increase the chances of damage due to condensation/corrosion.

Get the feeling that moisture and lack of corrosion protection from inappropriate 2T oils is at work here, but maybe Efuel is also playing a part as well?

Problem with Efuel is that there hasnt been any sort of proper investigation into the negatives, only really greenwash and propaganda from the manufacturers, so we will probably never know if Efuel is bad for 2T bikes or not.
All valid points. You have a very active trials scene in the UK with more opportunity for volume observations. I was surprised to find out the GasGas Pro used a custom ball or roller bearing with an extended race for a press-in seal, and that they were lubed from the transmission.

Regarding your observed bearing failures, of what brand(s) have they been and what symptoms led riders to conclude something had failed? Which brand was reportedly being fit with shielded bearings? If it's a sudden set of failures in one brand, I'd suspect a bad batch of bearings, where 'bad' means a material or process variance that was not caught.

There are five types of commercial ball bearings: open, single or double shielded, and single or double sealed. Open-bearing races are the same as the last two but simply lack a stamped steel shield that is staked into a groove in the outer race (one side or both), and has a small gap between the shield and inner race. The sealed bearings have seals of a rubber molded around a thin steel washer. They pop into the same groove present in the other two. The rubber lip runs on the inner race.

I have never seen a 2 stroke using shields, especially one lubricated by the traditional premix lubrication method of oil collecting on inner walls and running down a collector hole to the main bearing. A shield would block the pooled oil. I just talked discussed this will fellow technogeek Jon Stoodley. He said he took a tech call from a Beta rider who said his bearings had shields or at least a shield. Both us are scratching our heads over this. Shields are to hold in grease without contact seals. Perhaps the shield or shields will pool oil once it has slowly collected inside the bearing for a reservoir effect?

The GasGas Pro cases have casting bulges to accommodate both the traditional collector hole for premix lubrication and the two additional holes for passages to and from the transmission cavity. They do not drill the collector hole in the later models, and use their own, possibly patented custom bearing/pressure-seal combination. One advantage to lubricating from the transmission is oil consistently available at startup, there is more oil volume and the oil is much higher viscosity that fuel-cut premix. This should result into higher film strength and better boundary lubrication? Also, water getting sucked into the intake does not contact the main bearings, only the piston, rings, and cylinder. Same for the ethanol.. So is some of your reported main bearing failures are on late model Pros, it's probably not from ethanol, unless the ethanol is wiping the seals out, which should not happen anywhere near frequently.

motobene screwed with this post 08-03-2013 at 09:32 AM
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Old 09-07-2013, 06:50 AM   #27
motobene OP
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Adding to this thread from many weeks of getting inside both my Econo and Raga, and swapping parts back and forth, I can report my particular Econo has many identical parts to a Raga and is still proving one of my sweetest rides ever. Now it is owned by the next lucky fellow.

I think I just got very lucky on this particular mix of components.


motobene screwed with this post 09-14-2013 at 07:06 AM
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Old 09-07-2013, 03:29 PM   #28
Sting32
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Quote:
Originally Posted by motobene View Post
Adding to this thread from many weeks of getting inside both my Econo and Raga, ad swapping parts back and forth, I can report may particular Econo has many identical parts to a Raga. My particular bike is still proving one of my sweetest rides ever. Now it is owned by the next lucky fellow.

I think I just got very lucky.

Bene,

Been finding out the hard way several years now, that if we fail to get ethanol free gas, the oil actually gels into droplets, because even when stored it is vented and alcohol and the chemicals to keep the gas "viable" actually sucks water out of the air, and tries to suspend it...

Saying it passes through, IMHO experience, is a bad misnomer, and what is worse if you put it in a car that is stored more than 30 days, you are truly screwed... it better be full (less air space for it to suck the water out of the air/atmosphere that is in tank).

I believe our problem with the oil is the water, balls into jelly like substance. Try it, pour some 2 stroke oil into your water. becaues it doesn't like the water that is being trapped in (from atmosphere, not washing per se.) The alcohol based fuels have some high powered chemicals to keep the water "suspended" in the gas.

plus those chemicals eats the resin out of fiberglass tanks, as discussed here and elsewhere... if you ever buy fiberglass tank for like a TY project, you better coat it before it ever has a drop of fuel put in that tank.

Last year about now, Dad and I took a tractor, little "Farmall" A, and it hadn't been ran in at least 9 years. The gas in the tank was still better than the gas in my mustang, that was in it for a year (pump gas)... So, now I put non ehtanol race fuels into car when I store it, or avgas, I hear most with cars that are stored, people like Mr Lenno does too, because of the aggressive chemicals probably. Leaded gas used to stay good for several years...
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Old 09-08-2013, 06:28 AM   #29
motobene OP
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Quote:
Originally Posted by Sting32 View Post
Bene,

Been finding out the hard way several years now, that if we fail to get ethanol free gas, the oil actually gels into droplets, because even when stored it is vented and alcohol and the chemicals to keep the gas "viable" actually sucks water out of the air, and tries to suspend it...

Saying it passes through, IMHO experience, is a bad misnomer, and what is worse if you put it in a car that is stored more than 30 days, you are truly screwed... it better be full (less air space for it to suck the water out of the air/atmosphere that is in tank).

I believe our problem with the oil is the water, balls into jelly like substance. Try it, pour some 2 stroke oil into your water. becaues it doesn't like the water that is being trapped in (from atmosphere, not washing per se.) The alcohol based fuels have some high powered chemicals to keep the water "suspended" in the gas.

plus those chemicals eats the resin out of fiberglass tanks, as discussed here and elsewhere... if you ever buy fiberglass tank for like a TY project, you better coat it before it ever has a drop of fuel put in that tank.

Last year about now, Dad and I took a tractor, little "Farmall" A, and it hadn't been ran in at least 9 years. The gas in the tank was still better than the gas in my mustang, that was in it for a year (pump gas)... So, now I put non ehtanol race fuels into car when I store it, or avgas, I hear most with cars that are stored, people like Mr Lenno does too, because of the aggressive chemicals probably. Leaded gas used to stay good for several years...
How did we get back onto fuels?? Oh yes... main bearings... And it's all in good fun!

The 'high-powered chemical" you refer to may be the ethanol itself. Not sure what you mean about oil and droplets. Fuel is simply a solvent to the oil and it disperses into the fuel.

Ethanol is by its chemical nature hungry for water. Alcohol is/was used in many fuel additives pre-E10, to gather up water in fuel systems so it can burned off. There is capacity in the ethanol to absorb some water, and yes it will want to do so from the air, say through carb float bowl vents. But that takes time. The problems come when the ethanol becomes saturated with water (has reached its capacity to bind up with water). Add some time thereafter and nasty things happen.

E10 is just fuel. Roughly 90% gasoline hydrocarbons and 10% alcohol hydrocarbons. Ethanol actually raises the octane rating. Now I don't know what the percent MTBF is in non-ethanol or E10. MTBF is the nasty chemical that substituted nasty tetra-ethyl lead for slowing fuel burn. Since ethanol is an octane booster, I think perhaps E10 may contain less MTBF. Those who plaster 100% gasoline on their C-stores to gather business don't know that gasoline is not 100% gasoline, whether it is splash blended with ethanol or not.

Fuels are more complex than most folks know. To the complexity you can add what is called 'summer' and 'winter' gas formulations that apparently tweak volatility. You want less volatility in the summer because of evaporation rates, and more in the winter to promote starting. How they do this I don't know. But your trials bike can be harder to light off in winter if it has summer fuel in it.

You are right about E10 and longer-term storage, especially in wetter environments. Just gasoline is better. I store two dualsports in NM running E10. I run the fuel out of the float bowls, or drain them, and store from September to June each year (10 months). This causes zero problems because no atmospheric water can interact with the fuel. There is no fuel left in the float bowls, and the tanks are sealed. Each summer I turn the fuel on and they'll both start in two or three kicks, every year, every time.

The absolute key is keeping fuel dry, as in sealed containers, whether they are cans or modern motorcycle fuel tanks. Trials bikes aren't truly modern because they use a direct-vented gas cap (I think). That and the low volume of fuel means it's not the best idea to store a trials bike longer term with the fuel in the tank, especially if it's not chock full but is mostly empty, then fuel volume is even lower, and if you have E10 in there, it may water saturate faster. But the same is true for 'just' gasoline. Interaction with the atmosphere, or crap already in the tank (pre ethanol) is bad news, longer term.

Now if I were to store any bike more than a year, I'd probably drain all the fuel.

motobene screwed with this post 09-08-2013 at 06:41 AM
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Old 09-08-2013, 08:42 AM   #30
Twin-shocker
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I wonder whether adding ethanol to fuel is something that has more to do with greed/increased profit, than any real concern for the environment?
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