Crank Run Out Question

[Seeyacop]

So what is the proper way to measure crank run out? I have a 2008 XP 800 and i measured .0045 max and .0015 min measuing 1/8 inch from the end of the PTO side of the crank. The dealer looked at it and said yep .006 total run out but then they told me they have to divide it by 2 and get the run out of .003. Now the skidoo specs say no more than .0024 but BRP denied the warranty claim. They said it was within spec. even though it wasn't.

I have talked to another dealer as well and they gave me the same explanation for taking the two measurements and dividing by 2. I have talked to some experienced motor guys and they all told me they just take total run out and that is the figure they use. They also told me it should be less than .002.

Any other motor gurus out there that can shed some light on this?? I am pretty sure BRP is hoping the engine lasts so they don't have to warranty it but the last thing I want is a motor going down in the backcountry.

 

[SnowXTC]

Warranty claims are tough. You need a dealer that is willing to stand by you. A good dealer is a must. However, because the engine has not failed, a warranty claim may not be possible at this time. If it does, you will definitely have a basis for a new or rebuilt engine.

We have never divided by 2 to get the crank runout. It is what it is. It is not easy to determine sometimes though. Everyone has a different way of doing it. I will look back through my notes and let you know how I determined it. I was definitely the closest to what our crank guy had.

I understand about not wanting to run it with it out of spec, but unless you are willing to spend the $$ out of pocket, it may not happen. Put more pressure on the dealer to back you, he can force it though. If he feels it is warranty, then he should be stepping up to the plate and batting for you. He should be willing to do the work and then send it off for warranty.

I wish you luck. (speedy luck)

 

[Seeyacop]

Well I think my main issue is whether it was calculated correctly. Having it be .006 total is way out if this is the way you measure it. If you have to divide by 2 then it is close to being within spec but still off enough to potentially cause problems. BRP has a record of it but they are the ones who took the dealer's info and then denied the claim. Now if the dealer is measuring it wrong that is what I am really after here. If so BRP would have a hard time denying a claim if it was 3 times the spec it was supposed to be.

 

[gus bohne]

After 15 years of trueing and repairing cranks Never once has anyone said to divide by 2 thats pure bs..

why would one would even attempt to give that credence is beyond me.
Yamaha upped there spec on the srx as they found more and moer of them out of spec on the showroom floor..LOL. 002 turned to .009 to cover there asses , it burnt them in the end as it will your dealer and or the 3 foot tall frenchman at brp who came up with this lame duck blowoff..!

For the record, Runout when measured IN the cases is the opposite. It DOUBLES when the cases are released and the REAL runout is measured..

your measurment, if done with NO sparkplugs installed will be correct.
remove crank and repair NOW you will do it later in december if you wait.. your call.
If done with plugs installed the resistance will make the engine move around and skew your results

Get in contact with BRP race dept, tell them your story but tell them its an RS racer.. no warranty.. see if they tell you to RUN IT ..!! LOL
then you can go back to your dealer and explain that and see how they shuffle and dance around their own opinion..

At race school they tell the people to inspect for runout, over .002 remove and true your crank.. I don't know how this new BUSH math is working..

Gus

 

[Seeyacop]

Gus thanks for the info. You are affirming what I have thought and I just talked to another rotax motor builder and they told me the same. I am going to battle now with the dealer and skidoo, in a nice way. I am not confident in this motor after I measured it and the last thing I want is it going kaboom in the middle of the backcountry in a blizzard.

I am expecting the runaround I got before but this time I am going to keep going up the chain until someone addresses my problem.

 

[corncrackerjimmy]

I have never heard of dividing by two. Thats a bunch of crap. I did notice however when I rebuilt the crank in my 07 800R that the runout was differnt when checking it on v-blocks vs. in the case. 0.005 on the v-blocks turned into 0.0015 in the case.

 

[AKSNOWRIDER]

I have never heard of dividing by two. Thats a bunch of crap. I did notice however when I rebuilt the crank in my 07 800R that the runout was differnt when checking it on v-blocks vs. in the case. 0.005 on the v-blocks turned into 0.0015 in the case.

thats pretty normal..the cases force the crank straight.......

 

[SnowXTC]

Have you considered balancing your clutch?

How is the alignment on your engine and the alignment of your secondary? Been using up belts?

Just a few other things to consider and look at, especially if they fix it.

How did you check the crank runout or did you just have the dealer do it? Is this the dealer you bought the sled from?

 

[Tuesday]

I have posted numerous times on this issue with BRP. In the end they are willing to gamble taking out a motor then keep a crank in spec. The quotes I got from dealers on what it should be where all over the map, and most where pissed that I would even ask or know how to measure it. Again unless it bombs then they wont do squat, regardless of what the manual says.

They like the phrases, dont trust all the internet jockeys, that is a normal wear item that we wont cover, the list and rant could go on.

Theoretically 2 could play at that game, lets say if your motor where to go "down" then they would give you not only a new crank but a new block.

GL

 

[Seeyacop]

Pretty much exactly what I am finding except my dealer believes it is an issue but Ski-doo does not. Checked a 2009 today with under 10 miles on it and it was out of spec as well.

 

[Seeyacop]

Have you considered balancing your clutch?

How is the alignment on your engine and the alignment of your secondary? Been using up belts?

Just a few other things to consider and look at, especially if they fix it.

How did you check the crank runout or did you just have the dealer do it? Is this the dealer you bought the sled from?

Alignment is good, sled does not eat belts but it does wear the ridged inside part of the belt unevenly, possibly from the crank wobble. I checked the run out with a dial indicator 1/8 inch from the end, exactly like the book says. Also checked it just like a few crank shops told me to. If the crank was out of the case in V blocks it would probably be worse than it is in the cases. \

I bought the sled with 250 miles on it and put 700 on it last season. The dealer is not the dealer I bought it from but a local one to me. The dealer checked the run out and found it out of spec as well, believes it is an issue but Ski-doo won't admit it or fix it yet. I have talked to a couple of rotax builders now who both told me it will fail and even the max tolerance Doo allows for is too much. I am double the max tolerance Doo has published in their manual.

 

[SnowXTC]

I really wish you luck with BRP. Typically they are pretty good with their customers, but maybe that has changed.

Either way, while your crank is being trued, get your primary balanced. This could also cause the belt wear you described as well as cause unnecessary wear on the crank and cause it to fail sooner.

It all goes towards power; a true crank, balanced primary, properly aligned engine, properly aligned secondary clutch, gearing (good chaincase oil); it all adds HP to the track. Who cares what the engine HP is when you can't get it to the track.

 

[Snowjunky]

Either way, while your crank is being trued, get your primary balanced. This could also cause the belt wear you described as well as cause unnecessary wear on the crank and cause it to fail sooner.

It all goes towards power; a true crank, balanced primary, properly aligned engine, properly aligned secondary clutch, gearing (good chaincase oil); it all adds HP to the track. Who cares what the engine HP is when you can't get it to the track.[/QUOTE]


X2 What he said Well put SnowXTC

 

[Seeyacop]

Well looks like I am getting a new crank. Talked to BRP today and to my dealer and they told me to bring the sled back in and they would cover it. I am way out of spec and BRP knows it! I was nice about it and fortunately my dealer went to bat for me again with BRP.

 

[SnowXTC]

Whahoooo

But you should really get your primary clutch balanced. Everyone that I have gotten has been out of balance. 2 were within spec and one was out of spec (brand new, from the dealer). It is not that expensive and well worth it.

X2 What he said Well put SnowXTC

Thanx SnowJunky, except it is what SHE said, not he.

 

[Seeyacop]

Who are you having do the primary balancing?

 

[SnowXTC]

Brad Wursten

He goes by 1200PSI on here and has Power Addiction. He is in Logan, UT. I think shipping from MT was like $23 each way. You can PM him for pricing. He is quite reasonable.

 

[turboal]

one of the trajic issues with a crank that has to much run out is the excessive wear you see in the primary components .
when checking the crank the odd one has slipped the crank , meaning it is out of phase , not 180 degrees apart anymore , some checked had slipped 5 degrees . these units displayed an excessive amount of up and down movement of the clutch at idle , considerably more than the norm.
plays with total hp out put and a lack of being able to make top rpm , no matter what you try in clutching
this issue comes out of blowing a belt at wide open throttle , tremendous energy is released in one direction .

 

[Seeyacop]

Interesting thing with my crank issue is I never had a belt let go. I have been running proper alignment and clutching since day one and went all season last year on the same belt before it started to lose a cord. I am thinking that I got a bad one from the get go and that the crank was out of true from day one.

Seems like the quality control on these cranks needs to be re-evaluated. Rotax has had issues before in the past with poor run out and it appears nothing has changed. I was thinking maybe it was just because I had a 2008 but on a 2009 we checked it was out of spec too, just not as bad as mine.

 

[Sleds R Fun]

Be sure to let us know the run out on your new crank!!