Evinrude 1957 compresion question .

[duckland23]

Re: Evinrude 1957 compresion question .

your talking about the two covers with the gasket to them with 3 holes in it on the block right , not the front intake manifold ports where the carb is . I see four screws hole with a total for 8 one for each side of it . remove that and check the rings over inthe side right .

 

[duckland23]

Re: Evinrude 1957 compresion question .

I can rock the head on the glass on one end . Plus I can slide a starret 010 feller gage under one side and not the other . It should lay flat on the glass and not rock right . I can try a thicker feeler gage to see if its really warped . My uncle was a power brake operator at a factory and after he died I have his machine shop tools to check it . Whats the clearance I need to maintain the min and max pre thousands of a inch . I can ahve a machine shop machine it for me , But im unsure what they would charge .

 

[jbjennings]

Re: Evinrude 1957 compresion question .

Lay the head on a flat pane of glass with 400 grit sandpaper on it. Using a figure 8 motion, sand the head until flat. Yes, check the rings on the right (starboard side). the 2 covers over the side of each cylinder on the starboard side are the intake bypass covers. The intake ports will be underneath. Move the flywheel until the piston rings are under the ports to check them. I believe you've already found the problem--bad head gasket/warped head. Probably due to an overheat in the past.
JBJ

 

[nwcove]

Re: Evinrude 1957 compresion question .

Lay the head on a flat pane of glass with 400 grit sandpaper on it. Using a figure 8 motion, sand the head until flat. Yes, check the rings on the right (starboard side). the 2 covers over the side of each cylinder on the starboard side are the intake bypass covers. The intake ports will be underneath. Move the flywheel until the piston rings are under the ports to check them. I believe you've already found the problem--bad head gasket/warped head. Probably due to an overheat in the past.
JBJ

i suggest using a piece of 2000 grit sandpaper instead of 400 grit......post back when you get it flat.

 

[duckland23]

Re: Evinrude 1957 compresion question .

wet sand paper 2000 grit . It warped right like you guys said it was . This will get the compression up to specks .

 

[katman123]

Re: Evinrude 1957 compresion question .

Hey guys, as far as finding parts for these motors I have a 58 and a 63 johnson and have found any part I need at NAPA and ar resonable prices

 

[duckland23]

Re: Evinrude 1957 compresion question .

I just sanded the head and got it down flat better than it was . It was warped and now its flat I cant fit my 010 starret feler gage under it now so I must of done something right now . I called napa auto parts and they told me they dont have any in stock in the hole country or warehouse , there out of them . But I can get it fromthe internet anyway . Im going to call evinrude to see if they have it .

 

[duckland23]

Re: Evinrude 1957 compresion question .

Picture of the sanded head Look at to to tell me that you think

 

[64osby]

Re: Evinrude 1957 compresion question .

Looks nice. Did you check to see if the top of the block is flat and true? I had to mill mine down a little to get a good flat surface.

 

[duckland23]

Re: Evinrude 1957 compresion question .

Yes the block is flat , But the head will lay flat on the table or glass . But when on the engine block it wobbles a bit . Will that mean I need to still sand it more on the high side of it . I sanded it flat on my table and it is looking better on there but on the block its not flat .

 

[rockyrude]

Re: Evinrude 1957 compresion question .

To be sure it's absolutely flat you should use a piece of glass, your table top may not be dead flat.

 

[AlTn]

Re: Evinrude 1957 compresion question .

fire sealing edge of both cylinders from ~ 9 - 11 o'clock look really rough...I'd suggest taking it by a machine shop to get their opinion on milling it..around here that's in the $25 range

 

[duckland23]

Re: Evinrude 1957 compresion question .

I was there today they wanted 65.00 min and maybe more . I got it flat and placed it on the engine with a gasket and im at the same compression . My wet compression shot it up around 50 to 55 on the two cylinders . Thats more than 20 0/0 differents in the cylinders . I think my rings are bad . It pulls tight but my compression is so low . My gage is brand new and working right . I should have about 75 to 80 psi to run right . but I thought if i get 65 or 70 I would not complain . But I need to take it for what it is and it has bad rings .

I called evinrude today and replacment ring are availble from them for 40.00 , but Im unsure if thats for the two cylinders or just for one set . Im unsure and so was the man at evinrude . I can press down on the rings and they are springy and not right . I have some play in the bore but my cylinder bore maybe good for the standard set . I had a man that wants to sell me the set but I never heard from him .

You guys think if the air sielincer was blocker and if im not getting the right amount of air flow , would or could that cause a problem with compression . After all you need to suck air for compression to get a good reading right . Its just a simple thing I have maybe over looked .

 

[duckland23]

Re: Evinrude 1957 compresion question .

You think if the reeds where not supplying the right amount of air to the cylinders would i get weak compression being that I may have a bad set of reed valves .If I pull off the intake manifold and the reeds with it too . Can I test it for compression that way .

 

[duckland23]

Re: Evinrude 1957 compresion question .

AITn@

So you think that it will be need to be machined , milled down . If my dad was still working in itw a.k.a Illinois Tool Work in Chicago . I could get it machined for free . The would also bore the cylinders over size if needed to . But at this point in going to take her apart for rebuild . Thats better . I need rings , gasket kit maybe pistons Im not for sure . I just may but a good working power head too .