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Where to get a crank balanced?

Posted: July 20th, 2011, 3:53 am
by keysey
I was wondering if anyone can recommend a place to have a 89 CR500 crank balanced? Unfortunately the place I sent mine to in Australia has vanashed from the face of the earth and taken my crank with them.
Ideally I need a long rod crank supplied, rebuilt and balanced. Looking for a balance factor of 56% with my top end weight of 552 grams. Will need to have it shipped to Aus

Any info would be great

Cheers.

Posted: July 20th, 2011, 5:29 am
by Roostius_Maximus
if you know the factor you want thats starting to get easier. I havent finished the jigs i started for these cranks so I cant help you, but talk to members like seanmx57 or 2strokeforever who have had work done

Posted: July 20th, 2011, 9:41 am
by B440
www.surfnturfracing.com

I've heard of people getting work done from them. They are 20 minutes away from my home.

Posted: July 20th, 2011, 5:41 pm
by 2strokeforever
i wouldnt go to str, they deliver shit work (at least they did to me) :evil: sent it back at least 5 thou crooked.... i wish i checked before putting it together
and heres what it looked like
Image
i put it together anyways figuring it was minor cosmetic issue, then my motor sucked dirt in at the big kahuna so i took the crank in to get rebuilt and the guy spun it in the case and noticed the flywheel end was moving around way more than it should
he wanted nothing to do with it, so i sent it back to str and asked WTF is going on and he told me the grinding is from removing welds.... it wasnt ever welded... (the engine ice marks prove it is my crank)
had to buy another crank from kball1313 (thanks) to keep riding
while str "fixes" it
Image
and this time round i fire it on a truing jig as soon as it comes out of the box, 3 thou out... before i paid him he assured me that it would be within 1/2 a thou....
so i phone him back and he said its straight, i tell him i just watched it measured by someone who knows what their doing....
now get this he said i must be measuring from the wrong spot, im measuring from where the bearing sits to the crank ends....
he tells me thats the wrong way, the right way is to put the rollers on the tins and measure to where the bearing goes.... never seen it done that way, and it isnt held that way in the engine

so if he cant make a crank straight how the fuck did he balance it? balanced for 5 thou out of true clockwise?

$550 later (plus buying the other crank to keep riding) still vibrates about the same


i would recomend convincing roosty to do it, he delivers quality work
but if you want ill take my str crank out (rebuilt 15 hours ago) and sell it to you for the price of a new oem one

how did you come up with the 56% ??? when you get it finished let me know how it works

Posted: July 20th, 2011, 6:05 pm
by 100hp honda
2strokeforever wrote:i wouldnt go to str,
Image

Image
:lol: what a bunch of tards. looks like a highschool project gone wrong lol

Posted: July 20th, 2011, 6:58 pm
by seanmx57
I've got my str crank sitting on the bench. Now I'm curious about this. I really doubt it's not on the money cause it's very nice. I have a couple more to get done soon so I'm going to look into this.

Chris, I take it if I call steve (str) about this he will remember you?

So you are saying you can watch your flywheel wobble?

Posted: July 20th, 2011, 7:15 pm
by 100hp honda
purpose for the weld is to hold everything solid after its been trued up. pin has to be welded to the crank wheels :? :? . they welded the friking wheel without the pin in there then grinded the hole and put the pin in. scratching my head right now why somebody would do that.

or was only one side welded originally, then 2strokeforeever sent it back to get fixed and they had to grind out the weld and put in a new pin and never rewelded anything ?

but why would you only weld one side ?? WTF

ya im really lost now :shock:

Posted: July 20th, 2011, 7:28 pm
by 2strokeforever
Chris, I take it if I call steve (str) about this he will remember you?
for sure
So you are saying you can watch your flywheel wobble?
3 thou worth... at full revs i bet it bends a thou or 2 more

was a brand new slightly used crank when i sent it to him
he sent it back like in the first pic, hole was messed (look at the bottom of the pin in the first pic), sent it back so he welded around the hole.... too bad its still crooked

Posted: July 20th, 2011, 8:46 pm
by 100hp honda
wasnt welded for the normal reason but rather a attempt to fix some kind of problem with that side. all makes sense now. threw me for a loop there for a minute. well good luck :cool:

Posted: July 21st, 2011, 12:31 am
by keysey
Thanks for the info, I did get a reply from STR a couple of weeks ago asking if the cranks were the same from 87-01 but heard nothing since so i gave up.

Roosty, do you plan to be set up for the CR cranks anytime soon??

Posted: July 21st, 2011, 12:39 am
by keysey
2strokeforever wrote:how did you come up with the 56% ??? when you get it finished let me know how it works
I trawled forum's for ages and found someone that had used this figure in an AF and it was smoother through the midrange to top end. Apparently the stock cranks run between 59-62%. My engine is going into an 08 CRF250R.

Posted: July 21st, 2011, 5:36 am
by Roostius_Maximus
i know 56 is where STR is going, I dont want to stick a name on the other guys (cant remember without notes) but theyre also at 56%.
The company that builds the balancer gives a table of reference for the common BF people like, when i talked to them they also said 56.

they offer this table..

http://www.hinesindustries.com/document ... almass.pdf

an example of the same engine in different applications:

Tecumseh 1-cyl. 8 HP
go cart
60%

Tecumseh 1 cyl. garden tractor
50%

Tecumseh 1 cyl. go cart,
7,500-10,000 RPM
70%


Briggs & Stratton 1 cyl. Go Cart Racing
67%

Briggs & Stratton 1 cyl. Stock
50%

Posted: July 21st, 2011, 5:45 am
by Roostius_Maximus
I have parts made that suspend the crank on my balancer and drive it.
Where i'm at is not having the crank tooling to change the rod. I do offer the work, As I tell anyone who is getting it done I don't do it, but have an old hippy friend out in the valley who does an excellent job, timeframe is another issue :roll:

I want to make the jig i have also work with having the rod on the crank, like the harley loaded system that is available for the balancer. Theres a guide replacing the piston that pilots the rod, on this guide you alternate the weight depending on the piston. It'll work great, just havent got time to stop for a leak nevermind build something new and work the bugs out. Hopefully this winter.
Spliting the crank twice to balance it makes me nervous, thats alot of possibility for scoring the journal, likely what happend to the crank Chris sent STR, then they needed to build up the surface with weld or install a sleeve to repair it. Would have been better to offset that crankpin and stroke it if it needed that much work :lol:

Posted: July 21st, 2011, 5:51 am
by Roostius_Maximus
Other things that bother me is wondering what these guys did to install that mallory, is usually a pressfit deal, so did they split the crank a 3rd time to put it in then check it?
Why didnt they tig it in there if they were already working at the crank pin, Why did they need to add the weight? why not switch the program into remove and see where it wants it from. I'd rather have 8 1/4" holes if possible over adding 30+grams to the crank.

I've bought alot of cranks and obviously alot of 500 parts in the past that were blown up or junk so i can do some R&D on things, I have 2 test cranks at the moment, one with cans and 1 without, just so i can check out things from the backside and make sure theres room for it all. The cans have an o-ring seal both sides, so if 1 side gets welded shut the other side must also be welded.
Just getting a plan together.

Posted: July 21st, 2011, 6:25 am
by AlisoBob
Image

You guys are just a bunch of haters.... Surf and Turf are the bomb... Their in magazines and everything.

:x



( Insert sarcasim here)

Posted: July 21st, 2011, 11:50 am
by B440
2strokeforever wrote:...he said i must be measuring from the wrong spot, im measuring from where the bearing sits to the crank ends....
he tells me thats the wrong way, the right way is to put the rollers on the tins and measure to where the bearing goes.... never seen it done that way, and it isnt held that way in the engine

I don't fully comprehend what you wrote there. Could you possibly MSPaint me a picture of this? I was considering getting work done from STR and I'd like to understand how they are measuring vs. how you (and probably myself) are measuring.

Posted: July 21st, 2011, 1:37 pm
by Roostius_Maximus
check it like this...
Image

OR with centers at each end of the crank, not on the tin crank stuffers that the guys claimed to have been using.



for balance work right now most guys do things this way...
Image

this jig is what i'm talking about for the balance with no splitting

http://cart.rrcycles.com/index.php?main ... 4051bc8309

Posted: July 21st, 2011, 1:41 pm
by Roostius_Maximus
that lower link shows a picture of the same balancer I have, the Hines Liberator XP

Posted: July 21st, 2011, 4:07 pm
by B440
So STR says they balance cranks like this?
Image

I moved the rollers under the tins/stuffers.
mspaint woot!

Posted: July 21st, 2011, 4:45 pm
by Roostius_Maximus
that was how they claim to check for true, not the balance.

Posted: July 21st, 2011, 6:08 pm
by 2strokeforever
So STR says they balance cranks like this?
after hearing numerous bs excuses from the guy i can reconise it, he was just trying to confuse me into thinking it was straight....
Why didnt they tig it in there if they were already working at the crank pin
probably knew it was crooked and was nice enough not to weld it together
dont bother me i plan on replacing the rod often
Why did they need to add the weight? why not switch the program into remove and see where it wants it from. I'd rather have 8 1/4" holes if possible over adding 30+grams to the crank.
thats what i wanted, but he said it dosent work that way???

im starting to wonder if the guy took into acount the vesrah rod being 20grams (if i remember correctly) lighter

roosty once you get your balancing setup ready to test give me a call, dont worry about it not being perfect str set the bar real low

Posted: July 21st, 2011, 6:32 pm
by AlisoBob
2strokeforever wrote:.... str set the bar real low

Posted: July 21st, 2011, 6:58 pm
by seanmx57
Since when did STR start welding the crank pin. Last time I talked with him he said that he didn't see how someone could balance it via the disassembly process and then add the weight of the weld and have it come out right.

Something seems funny here. He's done many 500 cranks, never heard of a bad one, just very happy customers.

So why was this thing welded up?

Posted: July 21st, 2011, 7:18 pm
by 2strokeforever
So why was this thing welded up?
cause he mangled it the first time round.....
Last time I talked with him he said that he didn't see how someone could balance it via the disassembly process and then add the weight of the weld and have it come out right.
so in his opinion my balancing is worthless, but he still sent it back to me without any refund......
great customer service


look at the bottom of the crank pin, you can see theres a small crack, not very deep but wtf i sent it halfway across the world to get done right, not butchered
hes the only one to ever touch the crank, other than me taking it out. and i didnt use a grinder :roll:
Image

alisobob that video woulda been hilarious if it wasnt my crank, still funny

Posted: July 21st, 2011, 9:29 pm
by nmdesertrider
I was 100% satisfied with AZ crankworks. The rebuilt and balanced my crank for a very reasonable price.

http://www.crankworks.com/

IMO if you can rebuild multi-cylinder snowmobile cranks you can rebuild anything.