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Two burned up cranks in two months!

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I have a bike repair business as a sideline business. About a two months ago, I had a put a crank and top end in a customer's '02 450. The lower rod bearing was locked up and the cylinder had nickel coming off so we replaced it too. The customer admitted that he had not be diligent about changing his oil, and the bike had lots of miles, so I chalked it up to neglect.

Yesterday, I had another customer bring me an '04 450 with the exact same problem. Smoked the lower rod bearing and the cylinder is scratched up. This bike has relatively low hours. I have preached to this guy to change his oil often and to use real motorcycle oil, but now he admits that he has been using GTX from the auto parts store. What do you 450 experts think? Is this bike trashed as a result of the inferior oil, or is there a bigger issue here?

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Well if you frequent this web site much you will not find many issues with cranks so,,,,,,, yea, it might be the oil or the lack of changing it and the filter often enough. Keep in mind this motor holds so little oil it's imperative the oil and filter gets changed constantly. I change my oil, tranny and crank case side, after every ride and the filter every other ride.

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That's what I told this guy - every race change the oil - at least on the engine side. The tranny probably doesn't need changing quite that often. I know what he was thinking - "if I have to change it that often, I'm gonna use cheaper oil". Plus, he's probably not changing the filter near as often as he should.

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maybe he pulls wheelies for miles or ends up on his lid too often with the bike upside down and revving!

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there is no reason in the world why you should change your oil everytime you ride.. period. you should not have any problems if you change it every three rides and filter every other oil change. mine is an 04 i got in aug last year, never had this thing apart and runs the same as the day i got it. i dont piss around on this thing either including us nationals.. the oil out of the engine side is clean enough to put back in.. and whats his name that changes it every time must not need money and should put it into castrol gtx 10-40 because thats all you need.

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....AND the type of oil, Castrol GTX in this case, is NOT part of the problem. GTX is a great oil for bikes, as long as it is the "NON-energy conserving" type as stated on the API Service label on the bottle. I ran GTX 20w50 in my YZ426 for a long time no problems, and I also started out with my 2003 CRF using that oil. I have since gone to Mobil-1 15w50 (among others!) with no issues (and I won't have any).

It's not the oil, it's the lack of maintenance...

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I have preached to this guy to change his oil often and to use real motorcycle oil, but now he admits that he has been using GTX from the auto parts store. What do you 450 experts think? Is this bike trashed as a result of the inferior oil, or is there a bigger issue here?

The oil he is using is NOT the problem...

Real World Test Results

Are there any "real world" examples of long motorcycle engine life using automotive oils? There is a good one in the June 1996 issue of Sport Rider magazine in a report called the "100,000 mile Honda CBR900RR." The owner used conventional Castrol GTX oil, 10W40 in the winter, 20W50 in the summer. He changed it every 4,000 miles, changing the filter every OTHER oil change. No valve clearance adjustments were required after the initial one at 16,000 miles. And a dyno test against the same model with only 6,722 miles showed torque and horsepower virtually identical. The 100,000 mile bike was even used for some racing. In a subsequent follow-up, the same CBR had passed 200,000 miles and was still going strong! Plus, many motorcyclists have emailed me with their very positive results using nothing but automotive oils for years in a variety of rides. Oils have changed over the past 10 years, but that just means we need to be more careful in our choices.

http://www.yft.org/tex_vfr/tech/oil.htm

There are tons of other independent sites that back this up...those crank problems are lack of maintenance, plain and simple.

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hey Mike, I know your talking about Matts bike, I was there when it "BOOM"!!! I just wonder about the maintenance schedules on these bikes. I change mine every 3rd ride, filter and all, but the main thing I do is check the level before each ride!!! I know Matt doesnt do much bike maintenance, just look at the bike (sorry), now ashleys bike looks more maintained, but not for sure. I personally think, yeah they may be changing the oil but are they riding it with enuff oil in it?? Hey and on the bright side, at least neither one of them have had valve issues!!! BTW Mike, this is Mike Baldwin just to let you know....see ya

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Let me add one more bit of info to this. The customer told me on his last ride (not the ride where he trashed the motor) that the bike quit running during a race. He figured out that he had twisted the vent hose on the gas tank so badly that the bike starved for fuel and died. Now, I know that this is bad on a two-stroke because you lose your lubrication at the same time you're running the motor hard. But, on a 4-stroke, I don't see this causing much of a problem. Your comments???

The customer told me that he was running the GTX mentioned above without the energy conserving additive.

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I change mine after a weekend of riding...which includes a 40-70 mile trail ride(saturday) and an 80 mile race(sunday)... I think I punish my bike harder then most(plus its carrying 100lbs more then the average crf rider!) and the oil never comes out looking like new...

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Hey, Mike B - you're right, this is Matt's bike. I personally changed the oil and filter in it when he decided to get back to racing about six weeks ago. So, he has several races on it, plus some practice. He assures me that he has changed the oil several times since then, but I wonder about the filter. Ashley's bike may look better than Matt's, but it's because Ashley is on a strict sticker replacement/Armor-All program. However, he forgets things like oil and filters! Neither guy is going to make the mechanic's hall of fame. :cry:

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The problem is probably related to the oil level being low. I road race mine and after a 20 minute road race the level is down halfway. Now its less than a quart of oil total in there so half way is BAD, the water can be lost also and compound the problem with over heating.

its cheap to buy oil and keep it filled up and to change it, so why not,, a quart of oil is a few$ $ a crank, cases, bearings, cyl. ect are over a grand,

I have seen the piston stick and break the top end of the rod off then the rod goes right throught the bottom of the cases! very ugly

keep em filled up,

oh and riding long wheelies are fun but the oil pump will be sucking air and youl be oiling nothing whilst one wheeling it, no?

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HAHA, ashley on a sticker/Armor All program...that is soooooo funny man, funny and true!!! Good to hear that you changed the oil and that he said he has changed it as well. I am just wondering, do you fill it to the recomendations of the book, or did you fill the site glass all the way up, not just between the marks but all the way to the top? I have always heard and read on here to fill the site glass all the way, which is more than the book calls for, I put 700-750 cc in mine and always make sure the site glass is full before riding mine. I still think your on the right track with not scheduled maintenance, but ask Matt if he checks the oil level before each ride, these things do burn some oil!!! later Mike

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The difference between a non-synthetic engine oil and a synthetic oil really becomes apparent when your oil is 4 rides old, and you have blown some out the crankcase vent hose, burned some off, running low on radiator fluid, w/ an old filter.

That's when a synthetic oil would have made all of the difference in the world. That engine would have a much better chance of still running.

On this same subject I have been doing some fairly extensive modifications to my PSD. All of my 500 rwhp friends have been blowing engines left and right. We were doing some calculations based on tangential ring forces & thin film lubricant boundries. Basically, it became VERY clear that at the high cylinder pressures that we will be running (>1300 psi) that synthetic lubricants will offer complete lubricity where a petroleum oil will be long gone leaving my engine to run temporarily w/o motor oil when it is being ran at it's hardest.

My point being, hard working engines should ALWAYS have synthetic in them. ALWAYS.

PS. the '93 CBR1000 was well down on hp at 200K and it did not last much longer. I see no problem w/ ANY Jap I-4 engine running 300-400K miles w/ proper maintenance.

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Interesting info to say the least...I DO agree on the synthetic part. The thing is most MX bikes will get nowhere near the equivalent of 200k miles hehe...well, some guys probably do!

Seriously though, I love to hear a good oil story, keep 'em coming...

We need a special forum just for the oil related threads.... :cry: :cry: I can see the headlines now...

OIL: FACT AND FICTION!!!! DO YOU EVEN NEED IT???

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OIL: FACT AND FICTION!!!! DO YOU EVEN NEED IT???

Remember that infomercial where after using the product they drained the oil completely and the engine just kept running as if nothing had happened?

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Guys - thanks for all your feedback. You guys that are talking low oil level may be on to the real culprit. I usually fill a 450 to the recommended capacity and don't go by the sightglass. But, it's up to the customer to keep the level up to snuff. I can't follow them around with a quart of oil in my hand! Good comments also about the synthetic - it might save your bacon if you let it get a little low.

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there is no reason in the world why you should change your oil everytime you ride.. period. you should not have any problems if you change it every three rides and filter every other oil change. mine is an 04 i got in aug last year, never had this thing apart and runs the same as the day i got it. i dont piss around on this thing either including us nationals.. the oil out of the engine side is clean enough to put back in.. and whats his name that changes it every time must not need money and should put it into castrol gtx 10-40 because thats all you need.

Whether I change my oil(s) after every ride or not is my choice and I could give a rats ass as to your opinion! :cry:

PS - You're right, I don't need the money and on top of that, I also run 100% synthetic!! :cry:

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Boys, boys....Now, you two behave. :awww:I didn't mean to get an argument started. But seriously (and I know that I'll get crucified for saying this on this forum), I'd be real leery about buying a CR450 after seeing this '04 shelled out. The bike has not been neglected, IMO. This bike has low hours. The rider is a 150 pound novice/intermediate. And, from what you guys say, the type of motor oil is not the problem.

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