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Discussion Starter #1
I just got fixed my second gear and i was driving like 15 min.i was on 2nd and then my decompression blow off trought the valve cover:mad:. What may can cause this and is there better solution for the decompression.luckily the cylinder head is ok (just litlle rubbing marks)..If anyone had extra valve cover and camshaft i might need them.I try to add some pics so you can see what is the problem...
 

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I'll give you some bad news and that is that the valve cover has to be matched to the head as the cam in line bored and unless you get lucky the covers won't match and you will have problems. This means that you will need a new head and valve cover:eek: This is why I think I am gonna delete my decompression off of mine...
 

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I have no decomp on my Raptor,so far so good.Ow ya & I also have one of the very few miss mached head/cover set ups.It took a bit of work but my machinest/head builder set me up real nice. It is wise however to stick with matched head/covers.
Best of luck to ya.
 

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Yep that is a typical decompression mechanism failure. When you put it back together talk to Bigdaddy660R. He has some new decompression pins that have nuts on the back side. This keeps the pins from walking loose. It also comes with heavier machined aluminum weight covers.

What happens is the pins come loose. The weights fling out past the gear and catch the head. As you can see it the out come isnt real pretty.
 

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as others have stated......you will want to buy a new (used) head with matching valve cover. using the valve cover off of another matching set is a no no. you will have problems down the road
 

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Yep that is a typical decompression mechanism failure. When you put it back together talk to Bigdaddy660R. He has some new decompression pins that have nuts on the back side. This keeps the pins from walking loose. It also comes with heavier machined aluminum weight covers.

What happens is the pins come loose. The weights fling out past the gear and catch the head. As you can see it the out come isnt real pretty.
I tried to get ahold of bigdaddy a few weeks ago for a decompression fix and didn't get a response so I think I am just gonna leave it off. I had the decompression off last year and it was OK but now I'm just gonna buy a LA one way and run it with no decompression. I wish I could get one of those straps that hold in the Decompression Pin on the cam as I don't wanna weld It up just yet though. Might see what I can fab up for it though
 

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anyone know a machinist with a small line bore machine to bore the cam races and install some some new races to fix a mismatched head/valve cover?
 

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Discussion Starter #8
Ok.Thanks guys for advise.I have to talk bigdaddy660r.I wish i had know this before it happens but its little later to think about that.
 

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Ok.Thanks guys for advise.I have to talk bigdaddy660r.I wish i had know this before it happens but its little later to think about that.
Well I think the kit is around $125 bucks. Not a lot of people want to spend that kind of money and get no performance in return. No one really takes it serious until they have had one explode.
 

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I tried to get ahold of bigdaddy a few weeks ago for a decompression fix and didn't get a response so I think I am just gonna leave it off. I had the decompression off last year and it was OK but now I'm just gonna buy a LA one way and run it with no decompression. I wish I could get one of those straps that hold in the Decompression Pin on the cam as I don't wanna weld It up just yet though. Might see what I can fab up for it though
Use 2 or 3 small tack welds to hold the shaft in place. there is no pressure on it other than the oil pressure. When you want to remove it you just cut the welds with a dremal. Sand the welds down with a belt sander and it will be perfictly smooth.
 

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Use 2 or 3 small tack welds to hold the shaft in place. there is no pressure on it other than the oil pressure. When you want to remove it you just cut the welds with a dremal. Sand the welds down with a belt sander and it will be perfictly smooth.
Thanks that sounds like the easiest and I can do most welding just plugging that hole I don't think it would be to good looking with my little welder lol plus I might want the decompression one day
 

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Just a thought here, The journals look fine? the out side of the valve cover is just a cover. there is no cam support. so if a most of the pieces can be found could it not be welded. And carfully match the edges.
 

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Discussion Starter #13
Well I think the kit is around $125 bucks. Not a lot of people want to spend that kind of money and get no performance in return. No one really takes it serious until they have had one explode.
What that kit included??Some pics would be nice:) How much should i pay for used cylider head and cover?
 

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Discussion Starter #14
Just a thought here, The journals look fine? the out side of the valve cover is just a cover. there is no cam support. so if a most of the pieces can be found could it not be welded. And carfully match the edges.
I believe that cover is pretty much done for good :(
 

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