Yfz 471 Review

[jimmyjam]

Im planning to buy the hot rods 471 stroker kit............did any one have any problems or good results with this kit or any hot rod kits.....i dont want to buy a failcon (too much money)

[1fast06yfz]

imo i would get crank balanced otherwise it will vibrate

[jimmyjam]

??? i thought the canks came balanced

[r1yfz]

QUOTE (1fast06yfz @ Jan 31 2010, 03:47 PM)

imo i would get crank balanced otherwise it will vibrate[/b]

there balanced for a stockbore piston.... if you runa big bore it MAY shake

[climb-101]

i have had 2 different crank from them with a big bore setup, 1 had vibration and one didn't. the first one had some high RPM shake. on the second one the crank looked different and there is no vibration to the motor with a cp 98mm piston. I think some where along the line they changed there crank a little bit to help with the vibration prob.

[defiant]

Hot Rods did revise the balance on the cranks. If your doing one, just make sure it is one of the new ones.

[kb motorsports]

QUOTE (Defiant @ Feb 1 2010, 12:07 PM)

Hot Rods did revise the balance on the cranks. If your doing one, just make sure it is one of the new ones.[/b]

Luckily, we only have the new ones in stock. However, I must admit I never had a problem with any of +3 crankshaft from HotRod. I think some of the pistons being used with the +3 crankshaft was at fault. KB Motorsports

[jimmyjam]

I went on kbmotosports i didnt see the 471 stroker kit for a 06 yfz 450

[r1yfz]

first of all..... there is no FLAW in the cranks at all! the flaw is people thinking they can just throw a heavey piston onto something that is balanced for a light(stockbore) piston....

[climb-101]

QUOTE (r1yfz @ Feb 2 2010, 06:24 AM)

first of all..... there is no FLAW in the cranks at all! the flaw is people thinking they can just throw a heavey piston onto something that is balanced for a light(stockbore) piston....[/b]

ya I agree, the cranks are setup for a stock weight piston and when you toss a big bore on its going to vibrate some because of the exta weight. its a good idea to get it ballanced

[jimmyjam]

alright im going to get it balanced...............but were??? were do i go to.....and also the reason i poseted this is because i wanted to know if the 471 was good or not and how much difference it makes from stock to the 471........but the post do help thanks guy keep posting up what you think

[hpfreek]

QUOTE (jimmyjam @ Feb 2 2010, 02:30 PM)

alright im going to get it balanced...............but were??? were do i go to.....and also the reason i poseted this is because i wanted to know if the 471 was good or not and how much difference it makes from stock to the 471........but the post do help thanks guy keep posting up what you think[/b]

you can send the crank and piston to eather falicon or crank works cost is around $300

[jimmyjam]

WOW ok i expecting like 50 bucks ok um what if i just got the 471 stroker then just left my stock piston on it would it be fine

[climb-101]

QUOTE (jimmyjam @ Feb 2 2010, 05:13 PM)

WOW ok i expecting like 50 bucks ok um what if i just got the 471 stroker then just left my stock piston on it would it be fine[/b]

you dont have to ballance them but it is a good idea. you might get lucky and have little to no vairation.

[defiant]

QUOTE (r1yfz @ Feb 2 2010, 08:24 AM)

first of all..... there is no FLAW in the cranks at all! the flaw is people thinking they can just throw a heavey piston onto something that is balanced for a light(stockbore) piston....[/b]

Ummm....then explain to me why when I replaced my HR stroker crank with a HR stock stroke crank all my vibration woes went away. Everything remained equal, both cranks were manufactured by the same company, running a 98mm venom piston.

Also, where are all the posts of horrid vibration issue from people adding big bore kits to their stock cranks? Applying your logic, every big bore motor that wasn't balanced for said modification should experience the same vibrations as one with the HR stroker crank. Yet, I don't recall such issues......

[r1yfz]

QUOTE (Defiant @ Feb 2 2010, 07:17 PM)

Ummm....then explain to me why when I replaced my HR stroker crank with a HR stock stroke crank all my vibration woes went away. Everything remained equal, both cranks were manufactured by the same company, running a 98mm venom piston.

Also, where are all the posts of horrid vibration issue from people adding big bore kits to their stock cranks? Applying your logic, every big bore motor that wasn't balanced for said modification should experience the same vibrations as one with the HR stroker crank. Yet, I don't recall such issues......[/b]

so you added a heavier (98mm piston) to a crank that was balanced for a lighter piston (95mm) and it balanced?

do you see where you went wrong?

yes even a stock crank will vibrate with a 98mm piston added to it, some worse than others...

give it a try... a 100mm jsr piston on a stock crank is a good time!

[defiant]

QUOTE (r1yfz @ Feb 2 2010, 10:57 PM)

so you added a heavier (98mm piston) to a crank that was balanced for a lighter piston (95mm) and it balanced?

do you see where you went wrong?

yes even a stock crank will vibrate with a 98mm piston added to it, some worse than others...

give it a try... a 100mm jsr piston on a stock crank is a good time![/b]

Your side stepping....

All I am telling you is when I got rid of that piece of sh!t stroker crank and, install the OEM equivalent my vibration decreased dramatically.

Current crank is balanced for the stock piston...the stroker crank was balanced for the stock piston. Therefore, if everything is equal, I should still experience those earthquake like vibrations with the "OEM" crank. Yet, I don't.

So, where my confusion enters is when you tell me it's the pistons fault; not the crank. Admittedly, my motor does have a minor shimmy but, nothing compared to that mammoth annoyance of yester year.

In addition, the piston isn't spinning. It seems to me that 10 ounces of weight added to a object that is pushed/pulled up/down would have less effect than 10 ounces of weight added to a rotating assembly.

[r1yfz]

QUOTE (Defiant @ Feb 2 2010, 08:22 PM)

Your side stepping....

All I am telling you is when I got rid of that piece of sh!t stroker crank and, install the OEM equivalent my vibration decreased dramatically.

Current crank is balanced for the stock piston...the stroker crank was balanced for the stock piston. Therefore, if everything is equal, I should still experience those earthquake like vibrations with the "OEM" crank. Yet, I don't.

So, where my confusion enters is when you tell me it's the pistons fault; not the crank. Admittedly, my motor does have a minor shimmy but, nothing compared to that mammoth annoyance of yester year.

In addition, the piston isn't spinning. It seems to me that 10 ounces of weight added to a object that is pushed/pulled up/down would have less effect than 10 ounces of weight added to a rotating assembly.[/b]

was it a 3mill short rod that shook? if so you have to remember that that rodwas moving further and at diffrent angles.. wich had alot to do with the shakeing

[defiant]

IMO, if there is nothing wrong with the crankshaft that is in the motor now, leave it alone.

If your looking for a displacement increase, get a big bore. A lot less labor intensive. Like Lucas J suggested, up the compression a bit and port it. Should be a runner.

[jimmyjam]

QUOTE (Defiant @ Feb 8 2010, 01:23 PM)

IMO, if there is nothing wrong with the crankshaft that is in the motor now, leave it alone.

If your looking for a displacement increase, get a big bore. A lot less labor intensive. Like Lucas J suggested, up the compression a bit and port it. Should be a runner.[/b]

thats the thing i wish i could leave it alone but the crankshaft is locked up and the bearings siezed up so i HAVE too get a new crank so instead of putting it back stock i was going to make it a little faster but not stupid fast