Evinrude 70 head stuck

[racerone]

1/4-20 NC

 

[Nick0151]

 

[Nick0151]

1/4-20 NC

Thanks again racerone got the taps on order now went for the 3 stage hoping for best results. Il have to get some 1” plate. Take it I drill hole in the plate and go through that?

 

[racerone]

Make sure you research what size / diameter to drill in the plate.

 

[Nick0151]

Yes looked for the water jacket it’s 5.1mm and for the head blocks it’s 6.6mm.

Am I right in thinking what I do is drill completely through the 1 inch plate with the correct size drill for tap and then on one side I drill the same size hole as the diameter of the bolt so that the jig can sit over the bolt. Using the same pilot hole so cantered?

 

[SuperT]

Soak them with penetration oil also. Do that for a couple days and try the heat again. If they still won't come out , then carefully drill them.

 

[Nick0151]

I can only find the head bolts that have the flange head in 2 inch long they are 2 1/4 that came out take it I can’t use the smaller ones? Or can I use non flange head bolts?

 

[racerone]

Use a washer ????

 

[Nick0151]

I was thinking the same thing that be ok you think?

 

[Nick0151]

i have on my list flange head bolts;
18 off 5/16-18 unc x 2 1/4 seems like be standard size.

15 off 1/4-20 unc x 1 7/16 that seems like a strange size to me more availability of 1 3/8 or 1 1/2

Would using those be ok if so should I go 1/16 larger or smaller?

Thanks

 

[Nick0151]

Head is sorted was bit out but nice and flat now didn’t have to take much off at all. Two of the bolt holes that had snapped bolt in have been drilled and tapped for the water jacket to attach to so that’s head sorted ready to go back on..

Two questions
1 I’m going to dill the 4 head bolts out and try to tap without using helicoil but if I need to use them what length ones should I use know they are sold in diameter to size would a 1.5 or 2 be best or larger or smaller.

2nd question is

What are the torque specs for the head bolts and the water jacket bolts please?

And the tightening order?

Thanks in advance

 

[Nick0151]

It’s ok for my second question loaded up the service manual.

 

[Nick0151]

Guys would still like a answer over the helicoil and if the 1d is enough to use for head bolt.

But update on head looks lot better
Before ;




After

 

[RonSmith]

Did you guys ever use left handed drill bits to remove broken bolts?

 

[Nick0151]

I tried left handed dill bits and bolt extractor did nothing at all the bolt extractor snapped added so much more work I don’t think If you welded it could have got a stronger bond 40 years will do that..

 

[Nick0151]

Update I have put the head back on today and connected everything span the flywheel by hand seems ok tomorrow will start and see compression after all this work.

 

[Nick0151]

Well Racerone hats off to you!

Outboard is back together ran great (in barrel)

Ran for about half hour and done compression test…

We now have ;

1-127ish between 125 and 130
2- 130
3-130



Thanks for all the help and advice!