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Discussion Starter · #1 ·
Well I finally got some time to tear the top end off my Raptor and here is what I found. I thought the piston skirt might have broke off but I was wrong the Lower rod bearing must have went out. This crank was new last summer to. This is my 2nd hot rods crank failure. Its bad because I have 3 just Hot rods cranks in my barn now(1 was due to other failure and not related to the crank but it got ruined). I think I'm gonna try a barker crank "IF" I buy a new crank. Sucks because I have a brand new Kenz 13.5:1 that was gonna go in this motor and I'm glad I didn't put it in.

Here is the damage done. I have 2 bent exhaust valves??? Just slight bent and can't tell on the one and the other is more noticeable. Not much for marks on the piston from hitting it so I don't think it hit real hard. I wonder if the valves have something to do with the rod failing? I also ruined the cylinder but not much of a loss there because I was gonna junk it anyway after the new piston was installed. Also broke the cases to. Any one have any ideas.

This blew after a hard takeoff(but I have launched it WAY harder before) and then I got up to speed down a black top road and about 1/2mile of 4th gear light throttle it felt like the quad was on the rumble strip and she locked up.

Also i did notice a head gasket leak to You can see where it was blown at in the pic. Not the best pics you get the idea.
 

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The third picture of the connecting rod. it appears the connecting rod might have been cracked for some time. The mushroomed (shiney) in the top of the picture is sign the metal had enough time to contact repeatedly. The lower part of the rod is a clean break(sudden). is this the same way all your failures have been?
 

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Discussion Starter · #3 ·
Well it was running for about 10 seconds when something was wrong before it locked up. My guess is it cracked and was hammering together when it felt like it was rumbling right before it locked up. It didn't feel like a engine problem when rumbling it felt like a chassis issue until it locked up:p

Not the other fail was when the flywheel side of the crank broke off just like all the ones posted up here lately.
 

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A couple of things to think about when you assembled the engine and dismantled it after your rod broke............
Did you install the piston pin with a puller or did you use a hammer and punch?????????

Is the upper rod bearing (piston pin) seized???????????

The piston most likely hit the valves because of the broken rod............
 

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What ^ said about the piston hitting the valves when the rod let go...

That sucks man..

It sounds like you havent had much luck with those aftermarket cranks....I think its time to stick a stock setup with my a stage 1 or 2 cam in it and go ridin, IMO.
 

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What ^ said about the piston hitting the valves when the rod let go...

That sucks man..

It sounds like you havent had much luck with those aftermarket cranks....I think its time to stick a stock setup with my a stage 1 or 2 cam in it and go ridin, IMO.
I dont think you understand, buddy.. Most people just need this power, its addicting.. :)
 

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like willy said what type of installation was used to install the wrist pin? the break in the rod is a stress. side load of the rod during installation? bearing failure? over reving?
 

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To late now, but check your oil pump. You may have lost oil to to the crank. Remember, this is a dry sump system. Then go to a Corrillo rod.
 

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Discussion Starter · #11 ·
A couple of things to think about when you assembled the engine and dismantled it after your rod broke............
Did you install the piston pin with a puller or did you use a hammer and punch?????????

Is the upper rod bearing (piston pin) seized????????

The piston most likely hit the valves because of the broken rod............
Piston pin moves freely but didn't pull the wrist pin. I used a puller but kind of a makeshift setup:lol: Could have been the cause of it I guess but whenever installing the pin I was careful not to put stress on the rod for this reason. I will buy the right tool though. I know it hit the head because of the rod just was hoping I would get lucky and it not get it but I think it was due for some new valves anyway.

What ^ said about the piston hitting the valves when the rod let go...

That sucks man..

It sounds like you havent had much luck with those aftermarket cranks....I think its time to stick a stock setup with my a stage 1 or 2 cam in it and go ridin, IMO.
Can't even imagine what a stock rod would do:lol: as far a going slow again I would just sell them all. I sold my banshee that was mildy fast and my DS650 that would run anytime you wanted it with no problems ever with that thing just because after you ride a modded Raptor they were just plain boaring to ride. Kinda like riding a Underpowered polaris 325 or something of the sort.

like willy said what type of installation was used to install the wrist pin? the break in the rod is a stress. side load of the rod during installation? bearing failure? over reving?
Could have been anything said above but I will say I love the Top end power it has and it puts down alot more power in the high RPM:rofl: I build them to ride them and I don't baby them either but I also don't do stuff that I know hurts it either.

To late now, but check your oil pump. You may have lost oil to to the crank. Remember, this is a dry sump system. Then go to a Corrillo rod.
I haven't checked it yet but the cam looked good and I would think the cam journals would show if the pump failed. +1 on the Corrillo rod I have one I put in my 01 motor and that thing looks like it would preform well and hold through a valve beating the head real good.:D

But I did not use a hammer and punch I was surprised that most of the time I could force it out by hand with out my make shift tool:lol: I could put a short socket extension on the pin and grip the piston with my hand and push with my palm to get it out and in.
 

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If you did not put any side load stress on the rod by handling it or when installing the piston, I would talk to the manufacturer, unless this was bought used. Then you dont know what that rod went through before you got it.................
That is the only thing that could have caused your situation since my experience with these rods shows they are very strong..............
 

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Discussion Starter · #13 ·
If you did not put any side load stress on the rod by handling it or when installing the piston, I would talk to the manufacturer, unless this was bought used. Then you dont know what that rod went through before you got it.................
That is the only thing that could have caused your situation since my experience with these rods shows they are very strong..............
My last attempt at getting ahold of Hot Rods was a fail but it has been a year from when I bought it. Do you think I can just put a rod on this crank? I have a good rod on my other broke stroker crank(Hot rods:() but if I can make a good crank out of the 2 then I will do it. You wanna rebuild a crank for me Willy?

My guess is that I more then likely caused damage to the rod some how or another. I will make up a better piston pin puller though:lol:
 

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Discussion Starter · #15 ·
Will this be your first time going with barker crank.
Yeah I have not went with a Barker crank yet. I'm not sure what I am gonna do yet??? get a rod for this crank or get a +6mil barker crank. I have looked at this alot and think the +6 would be a better setup then the +8 I was gonna go with. I just don't wanna drop another $500 right now but think it would be my best bet. Might just wait until the spring to build it up. I just wanna get everything all done this winter so I am not working on this damn thing all spring-summer and burning up all my $$$ on parts. I would like to ride the thing next year. The way it looks now I might just not be riding the rest of the year:(.
 

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My last attempt at getting ahold of Hot Rods was a fail but it has been a year from when I bought it. Do you think I can just put a rod on this crank? I have a good rod on my other broke stroker crank(Hot rods:() but if I can make a good crank out of the 2 then I will do it. You wanna rebuild a crank for me Willy?

My guess is that I more then likely caused damage to the rod some how or another. I will make up a better piston pin puller though:lol:

My stock crank is still turning in an engine that has been trail driven, mud bogged, did atv pulling and ran an oval track for 3 years.............
My stock rod went in the garbage years ago though, it was replaced with a carrillo rod, thney are expensive but strong, my rhino has a hot rod connecting rod on it with a stock crank.

As far as rebuilding your crank, I can do that and I have been rebuilding cranks since 1994. My first crank was a from a 3 cylinder Thunder Cat engine, my own.................
 

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Discussion Starter · #17 ·
My stock crank is still turning in an engine that has been trail driven, mud bogged, did atv pulling and ran an oval track for 3 years.............
My stock rod went in the garbage years ago though, it was replaced with a carrillo rod, thney are expensive but strong, my rhino has a hot rod connecting rod on it with a stock crank.

As far as rebuilding your crank, I can do that and I have been rebuilding cranks since 1994. My first crank was a from a 3 cylinder Thunder Cat engine, my own.................
We will see when I get it apart how good the rest of the crank looks and see if I will rebuild it or not. I do have another crank but I it has been sitting around the barn for so long it makes me not want to trust it after this one broke. Hmmmm what to do.
 

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I've still got my stock crank if you want to take a look at it when I get home. I know you will be putting a new rod in it anyway, so it would be worth your time. I'd even trade you straight up for that Sparks or something comparable haha. I won't hold your feet over the coals.
 

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Discussion Starter · #19 ·
I've still got my stock crank if you want to take a look at it when I get home. I know you will be putting a new rod in it anyway, so it would be worth your time. I'd even trade you straight up for that Sparks or something comparable haha. I won't hold your feet over the coals.
Sorry cdg I already am well stocked on cranks:lol: I have 2 or 3 stock cranks for some strange reason. I have one that is in real nice shape and if I get a big crank made up from Barker I will send that one. I think you should just buy a bunch of parts off me and you build up a motor so you can go just a tad bit faster:rofl:
 

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I'm faster than you. At least for the moment, lol. I can say this with certainty because you don't have a bike that runs. And even if your '01 runs, as long as I keep you in sight for 10 minutes, I got you because then you have to stop and put oil in it, haha!
 
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