Can't find headbolt helicoil

[Patch]

I can't seem to find a M8-1.0 helicoil kit around here. I did find a M8-1.25.
The m8-1 is a find thread with the 1.25 is coarse. Online the fine threaded one is $50-sum but the coarse one is only 20 over at Ace.

So I come to you asking... would be ok to switch just one head bolt out for a 1.25 pitch thread? it still has the same diameter just different thread size, right? :???: and could I get a bolt thing that is threaded all the way up or does it have to have the smooth part in the middle?
This way, I can save time and money to just buy the cheaper and available Helicoil and just replace one stud.

PS having only one of the four studs "helicoil"ed and a different pitch won't cause catastrophic failure, will it? Thanks for reading my long and boring post

 

[locoWelder]

go for it patch ,it will work fine and you can use allthreed

 

[Patch]

Thanks Loco, Ill try that hopefully tonight...almost solved. Just alittle testing to do.

 

[go you good thing]

Did the very same thing through this week.

I could get both 1 and 1.25 pitch helicoil but I could not get stainless threaded rod in 1 so I just bought the 1.25 helicoil and rod.

I will hopefully get some time this weekend to attempt the fix.

With my motorcross bike the head bolts have thick copper washers under them without a lock washer. I am thinking these washers expand quickly with heat and therefore lock the nut??????? Your the metal man loco what do you think :?

Getting thick copper washers is proving to be difficult so I may have to go get the same part as the motox bike.

 

[Patch]

Go you good thing... where did you find a M8-1 helicoil? Most suppliers don't have them becuase its an odd size to stock. Where did you find it...advanced autoparts or something? thanks

 

[go you good thing]

I got it from what I would consider a specialist supplier called Car Parts Plus here in Lonsdale South Australia. I found this place as my car mechanic gets his parts there so I figured they must be good.

When I spoke to them on the phone they said they could get the 1 pitch but they would have to order it in.

When I picked the 1.25 kit up it was not the Helicoil brand it was a Recoil brand. They where only two thirds the price however so I thought I would give it a go. When I open the package maybe tomorrow if I find any website for Recoil I will post it here.

 

[srdavo]

my 2 cents

why not re tap the 6mm hole to 1/4" & replace the stud.

or maybe 7mm? new studs are WAY cheaper than helicoil

 

[go you good thing]

srdavo the head bolts are 8mm diameter by 1 pitch as standard.

We are having trouble getting this size so the 8mm x 1.25 is available.

I have just looked up the tech manual for Recoil and it does not have the M8 x 1 option so the guy at my local auto parts store is either incorrect or has something else in his mind.

I will call him on Monday to see if he can get the 8 x 1.

 

[srdavo]

wow....my 48cc and 55cc engines have 6mm head studs. I just went out to measure them.

:???: my bad.... carry on, gents

 

[go you good thing]

wow....my 48cc and 55cc engines have 6mm head studs. I just went out to measure them.

I have just noticed that both Patch and I are running 70cc so I am not sure what the others are. Anyone here have any idea if they are all 6mm?