had my engine spin balanced

[skank]

my experience

My facts...

I have two sleds that have the full balance kit installed by Perks himself at his home. Had this performed just for longevity and less part wear. Sleds seemed to vibrate a little less. No clicker change.

2009 800xp summit- 2 recoils broke, flywheel flew apart, mag housing broke.

2010 800xp summit- 4 recoils broke, flywheel cracked

(both sleds had recoil spacer installed)

I loaded up both sleds and delivered them to his house last monday. He stated that there was a recall that I did not know about. Said he is switching to carbon steel flywheels and would investigate the recoil spacing issue. He did not communicate with me or answer phone calls, texts, and emails until this morning (8 days) He had a family issue last week. He is working on getting the sleds fixed now.

Money and time I have invested in this experiment..

personalized in-sled balance kit- $450 x 2 sleds = $900
diesel & wear for two trips to his house- = $300
meals- = $100
2 days off work- = $800
6 recoils- $170 x 6 =$1020
1 mag housing- = $ 75
being towed out of the back country at night =priceless
beer and pizza for the rescue crew- = $100
trips being cut short from broken recoils =priceless
fuel to mountain to turn around and come home = $300

Price to pay for trying something aftermarket for a snowmobile= $ 3595

 

[sledr2]

My facts...

I have two sleds that have the full balance kit installed by Perks himself at his home. Had this performed just for longevity and less part wear. Sleds seemed to vibrate a little less. No clicker change.

2009 800xp summit- 2 recoils broke, flywheel flew apart, mag housing broke.

2010 800xp summit- 4 recoils broke, flywheel cracked

(both sleds had recoil spacer installed)

I loaded up both sleds and delivered them to his house last monday. He stated that there was a recall that I did not know about. Said he is switching to carbon steel flywheels and would investigate the recoil spacing issue. He did not communicate with me or answer phone calls, texts, and emails until this morning (8 days) He had a family issue last week. He is working on getting the sleds fixed now.

Money and time I have invested in this experiment..

personalized in-sled balance kit- $450 x 2 sleds = $900
diesel & wear for two trips to his house- = $300
meals- = $100
2 days off work- = $800
6 recoils- $170 x 6 =$1020
1 mag housing- = $ 75
being towed out of the back country at night =priceless
beer and pizza for the rescue crew- = $100
trips being cut short from broken recoils =priceless
fuel to mountain to turn around and come home = $300

Price to pay for trying something aftermarket for a snowmobile= $ 3595

Time and money spent OUCH!

This review PRICELESS!

Thanks!

 

[XtDoo]

perks balancing

I have 3 buddies that had the Perk's balancing kits done, gone through:

2010 xp 800 - 3 recoils with broken springs in less than 200 miles

2010 xp 800 - no recoils worried about breaking recoil spring, so he removed the mag side balance disc.

2008 xp 800 - 2 recoils in less than 100 miles

All three are very happy with the smoothness of the engine and increase in performance. Can go down 1 - 2 clickers with kit. Really like and want to use the kit but this recoil issue has to be resolved. They called Joe the other day and he claimed he only knew about one other recoil problem. They don't want to bash anyone or any business but like any business they should stand behind their products.

 

[Matte Murder]

Man this whole deal stinks for the guys that have had serious problems with Perks Spin Balancing. Does this site help it's members get things straightened out with other members/vendors? Do members/vendors get black listed or banned from the site for serious and repetitive issues with products or services? Perk's needs to step up to the plate and fix the issues and reimburse customers for costs incurred. Also, I would love to hear a response from Perks about these problems. He is on this site and responds to questions about his products frequently. Why no response now? Again, this whole thing stinks and needs to be resolved.

 

[madmini660]

Man this whole deal stinks for the guys that have had serious problems with Perks Spin Balancing. Does this site help it's members get things straightened out with other members/vendors? Do members/vendors get black listed or banned from the site for serious and repetitive issues with products or services? Perk's needs to step up to the plate and fix the issues and reimburse customers for costs incurred. Also, I would love to hear a response from Perks about these problems. He is on this site and responds to questions about his products frequently. Why no response now? Again, this whole thing stinks and needs to be resolved.

I was just trying to help other sled heads out of what i would say is giving your money away for someone else's r&d and I couldn't tell a thing i never had to lower a clicker on my clutch or anything couldn't tell if it ran smoother after balance all i know is it eats recoils and it didn't before

 

[PJ-Hunter]

My facts...

2 days off work- = $800

Work 8 hours a day, 5 days a week. $400 a day=$50/hour

Holy crap! What you b*tchin about??

 

[800PowerFanatic]

I just called Joe the other day and he picked up the first time and I told him what I had been reading on snowest and I was concerned although I haven't had any problems and he said to send back all aluminum rotors and the spacers because there has been a recall. He was worried when I called because I hadn't gotten a call earlier. So he hopes he got to everyone by now. The reason for the recall was because his machinist wasn't checking his work and some of the spacers were a couple thousanths to small. He also said that the new rotors are not aluminum but are now high carbon steel.

 

[XtDoo]

balancing

Add 1 more recoil for today's ride.

 

[970SnowSlayer]

I just called Joe the other day and he picked up the first time and I told him what I had been reading on snowest and I was concerned although I haven't had any problems and he said to send back all aluminum rotors and the spacers because there has been a recall. He was worried when I called because I hadn't gotten a call earlier. So he hopes he got to everyone by now. The reason for the recall was because his machinist wasn't checking his work and some of the spacers were a couple thousanths to small. He also said that the new rotors are not aluminum but are now high carbon steel.

No offense, but something tells me you and perks are buds..





If he is "recalling" as stated, has anyone gotten the "recall" message yet?

"a couple thousanths too small" ..? too small = more distance from the recoil, how would this logically be the culprit? and a couple thou? if a couple thou seperates a working kit from one that grenades, in this particular design scenerio, then someone needs to hang up their "engineering" gear.

Best of luck to those who are brave enough to test this new steel rotor, as you'll be guinea-piggin' a new balance recipe. (steel vs. aluminum. how ever perks was setting up the aluminum rotors with weights or whatever they were doing will obviously have to change with the difference in weights of the materials) not to mention, whats the steel rotor weigh in at? ...should help it rev as fast as weedeater with the choke on. Really, this just doesnt seem logical, for the benifit of the engine performance ( it may solve his self-created issue of the rotors tearing up recoils...) . if its performance your after, adding more mass to the rotating assembly will not accomplish this. nearly every component built for a high performance engine rotating assemblys have one thing among others thats high on the priority list....losing rotating or reciprocating weight! If its the reliablity claim thats got you sold on it, then I understand your motive...but! if you want reliability, then my advice is contact a one of the many reputable engine builders both on this site and elsewhere. These are the guys that build these engines for a living, and have decades of experience with them. Both for HP or for reliability, although its not cheap, tell them what you want, and they'll get it done. There are certain fundamentals of engine bulding that only a guy thats been doing it for a long time has. Lots of do's and dont's, things only learned from expierence, and little things that make a 2 stroke engine reliable. The builders know how to get it done. .."revolutionary" mods rarely pan out in this industry.

Like many other guys on here have voiced, the whole system that perks utilizes to balance just doesnt seem to make sense. Balancing a motor without ever seeing it?!!?! c'mon. downright wreckless. I've been totally amazed that after the very very very small percentage of 800r motors (out of those built by rotax) that he has actually had his hands on, he is confident enough to build a universal balancing kit for this engine. I build billet crankshafts for a living. I have balanced a few... and let me tell you, I have yet to see two identical cranks spin up absolutly identically. its nearly impossible. gram for gram, a few extra strokes of a file, or a little extra deburr on an edge, and the balance has changed. I simply cannot not support perks theory on balancing these motors. Ive never seen weight ADDED to correct an unbalance on a 180 degree (2 or 4 cylinder) crankshaft, only removed. I believe the motor runs smother because of the dampening effect the pie weight has (if im not mistaken winterbrew was thinking along the same lines), and possibly some unbalance correction, but its still a far cry from being accurate and a satisfactory way to balance this assembly, imo. How can this can be refuted?, as he has not actually checked the vast majority of the sleds this kit has been installed on, how does he know hes not creating more of an unbalance, or one that was never there to begin with? What if someone actually had a motor that was balanced correctly from the factory? The theory just doesnt work for me. All the verbage bling about cruise missles and whatnot, seems to have gotten everyones faith?, dang. read; "i've got some ocean front property in wyoming I'd like to sell you" .... and yet not a single engine builder, or engine-savvy person ive spoken to has agreed/endorsed (or understood for that matter) perks method of balancing. I do believe in zero balancing the clutch assembly, and properly balancing the crankshaft. Clutch balancing is absolutly nothing new or revolutionary either. Perks method...not for me. to each their own.

Balance your clutch, have a builder make internal improvements to the crank (weld, true) and balance your rotating assembly, keep your isoflex packed, set it up right, and you"ll have a reliable motor. Its too bad that the OE's cant just give us that (reliability) from the factory...but i'm far to tired to even think about that saga. People need to protect themselves from mods that could potentially leave them stranded, especially when they do the mod for the single purpose of reliability. We're all going further and further into the backcountry, we gotta stay wise. To those who have already purchased this kit, I hope he will take care of you guys and any problems you may encounter, and you'll be able to enjoy the rest of the season. I hope i didnt piss everyone off, but it may just save someone a 30 mile walk out, or worse.

 

[sledr2]

I like all this feedback.

So I see that perks is reading this thread right now.

Rebuttal........

 

[cabinman]

guess i'll be pulling mine and sending it back to him as well...

 

[800PowerFanatic]

I've never even met the guy, just talked to him on the phone. And you seem to know what your talking about and I am starting to agree with you. Except I don't understand the outcome? Why did his pie thing take so much vibration away?

 

[970SnowSlayer]

I've never even met the guy, just talked to him on the phone. And you seem to know what your talking about and I am starting to agree with you. Except I don't understand the outcome? Why did his pie thing take so much vibration away?

No problem, just sounded like you were maybe friends or something. Good on you for giving him the benefit of the doubt.


I dont know everything nor claim to. I do however have a daily encounter with crankshaft balancing, so I am familiar with industry standards in that respect.

Why did the 5th counterweight (pie weight) smooth out your motor. imo, two reasons. simply put, mass absorbes harmonics and vibrations, the added weight on the end of the crank has a dampening effect on the engines harmonics. Also, its totally plausible that perks has in fact found a common unbalance denominator in the percentage of motors he has sampled. (Although with out complete disassembly and running the crank on a crank balancer im not sure of how this would be factually verified) And therefore, the 5th counterweight could be bringing the balance into the ball park. BUT, my main point is this is not a standard method for doing so, especially on a 180 degree crank, AND, its simply that...the "ballpark" . A properly balanced crank when spun up on a crankshaft balancer should require less than 3-4 grams of weight added, or in the case of 180 degree (2 & 4 cyl) and 120 degree (6cyl) crankshafts, removed, to bring it into zero balance. That is why, this method imo, is not a correct way to balance this crank.

I see no scenerio where every crank rotax has produced for the 800r motor, when the perks kit is installed, when properly checked, would spin up <3gm. from zero balance. In mass manufacturing there are SO many variables that would have a direct relation to this. There are common variables in this type of a production part (crank). for instance: Forges/casting dies -- usually there is more than one forge or die to build parts like cranks on a mass production scale, not every forge or casting may release the part the same after the material has solidified. Sometimes material, (weight, could possibly be counter-weight (if that makes sense) ) sticks to the dies, and therefore not every single forging or casting thats produced is exactly the same, and will not balance exactly the same ( at least without full machining of every raw surface to square the part up. ..this is not done on our cranks). So there is manufacturing variable #1. 2. Tolerances, design, and overall specifications are always subject to change during production. Again, how can he be that confident that the small sample hes taken represents all possible variations from the manufacturer? Rotax also has suppliers, sometimes suppliers of parts change, therefore there are design differences. Another example, ive seen some OEM cranks that instead of grinding all the main bearing sizes to the same exact diameter, they just hit the mains in the crank grinder, get them +/- a few thou from the target diameter, then choose from an assortment of bearings and match the bearing to the main diameter (doesnt make much sense...but believe it or not, this kinda stuff takes place). this is a fast, cheap way to get stuff out the door, and in mass production it happens. This is an example of how not every part that comes from the same mfg facility is exactly the same as the next.

I'm not saying he doesnt know anything at all about balancing, but there are differences between a turbine wheel and an internal combustion engine. There are specific ways to analyze the unbalance of different types of compenents. Balancing is all the same to a certain degree, but it hit a fork in the road when you are not working with a symetrical compenent. Adding a counterweight on to the end of a crank is not an industry practice for correcting unbalance (especially in the performance sector) in this day and age. Why are recoils being destroyed by this weight? imo, its simply an engineering oversight. The blame on the machinist not checking his parts is an easy out, and is a common excuse, heard it a million times. again, how does a few thou keep recoil from being eaten up? if a few thou is all the tolerance there is, then someone (who ever engineered this product) needs to revise his specs! ...recalls and revisions to me means that thurough testing on a viable amount of sleds in various conditions was not fully executed.



sorry for all the edits, I type faster tham my eyes can edit...

 

[winter brew]

Good post.

I have a hand in vibration/resonance testing on a daily basis. Add mass to an engine and it will "feel" smoother at lower RPM's. The question is what does this added mass do as far as stress on components at 8,000rpm. Without extensive durability testing at these RPM's there is no way to know.
Not saying this is bad for an engine, but how do we KNOW without testing?
I find it hard to believe that every engineer at Rotax, Suzuki, Yami, etc....could have added a little mass and been able to add life, performance and reduce vibration. If they could have they would have. The amount of time and effort that goes into design and test is very extensive.
I see on a weekly basis sometimes the difference between a component failing rapidly or lasting virtually forever can be VERY minute. What we interpret as bad (low RPM vibration) might be a side effect of what allows an engine to last at high RPM where there is much more force being exerted...????

 

[hockeyb4]

Not that the OEM design could not be improved but as far as the motors go the testing that goes into them is insane. and like winter said if they could get those results without determent in the long term I would bet they would have. You can bet you would read about it all over their advertising as well.

 

[jacmmaxwell]

I agree, he has been quick to pimp this process on here for a while now. But not even a peep on this thread?

 

[970SnowSlayer]

Good post.

I have a hand in vibration/resonance testing on a daily basis. Add mass to an engine and it will "feel" smoother at lower RPM's. The question is what does this added mass do as far as stress on components at 8,000rpm. Without extensive durability testing at these RPM's there is no way to know.
Not saying this is bad for an engine, but how do we KNOW without testing?
I find it hard to believe that every engineer at Rotax, Suzuki, Yami, etc....could have added a little mass and been able to add life, performance and reduce vibration. If they could have they would have. The amount of time and effort that goes into design and test is very extensive.
I see on a weekly basis sometimes the difference between a component failing rapidly or lasting virtually forever can be VERY minute. What we interpret as bad (low RPM vibration) might be a side effect of what allows an engine to last at high RPM where there is much more force being exerted...????

dead on. harmonics change ALOT as rpm increases and decreases. a perfect example is right inside everyones left hand side panel of their sled. watch your clutch at idle, watch you clutch at >4k.

im not saying that the harmoics produced by the 800r is right, or wrong. (i would say that it most definitely has room for improvement, ie: runout!) but like brew and hockeyb stated; the amount of r&d that rotax does is far more extensive and advanced than most any private operation could ever support. Ill place my chips with rotax on this one.

 

[eddy]

Balance and weight

1) The 800R shakes more than any Rotax I have owned. Fact!
2) Back in the day there was an option to add 1 or 2 pound crank weights to single cylinder two stroke dirt bike engines (typically 250cc and up). This resulted in better traction and a more controlled powerband that made the bike perform better in most every condition except perfect traction. I know of no additional crank failures resulting from this external weight. Even today: XC and Enduro bikes have the bigger flywheel even when the lighting coils are not required. MX bike are the only ones with the lightest (quick revving) crank/flywheel assemblies.
3) With all the drive train components of a snowmobile (generator, clutches, shafts, chains, gears and track) considered: It would seem that a little more crank weight would cause very little negative effect IMHO.
4) Manufacturers have little incentive to make snowmobile engines that last much longer than the warranty period. It would appear that an alarming percentage of 800cc do not make the 300 hour engineering goal before a major rebuild.
5) When we crossed the threshold from a 700cc engine to an 800cc engine all hell seemed to break loose as far as crank failure - irregardless of brand. Most 700cc engines made the 300 hour mark. How many 800cc make it within the run-out tolerance limit?

They told me step up, pay your money and take your chances. Maybe a higher performance 700cc two stroke would be a longer life safer bet?
I still am not desiring a heavier and lower performance four stroke for my machine. That would seem to define the box the engineers are in.

 

[800PowerFanatic]

I still don't know where I stand on this. Adding weight doesn't make much sense but then sometimes some way it can, if Perks have really done their research and testing very intensively is it possible at all? I mean when I had his product on the vibration was there till 2300 RPM then completely disappeared. Why does it disappear on all 800R's at 2-2300 RPM? And What about the MPH gain ?

 

[winter brew]

Rotax added the ring gear to the primary on the 800R for this very reason....to reduce resonance at certain RPM's....so adding OR subtracting anything WILL without any doubt change the RPM of resonance. The question is, at what RPM. You would have to test at all RPM's with accelerometers to KNOW what is occuring.
Maybe this does add life to an engine....has there been endurance testing done? How many engines with 200+hrs of run time at operating RPM?
Not bashing....just asking.
I'm all for products that work....hopefully the unfortunate side effects seen in this thread are a thing of the past.
We all know that is never the intention and I'm sure Joe is as upset as anyone when this happens to his customers.