G Dane,Paul Moir Help please...

G DANE · Aug 2, 2005

Re: G Dane,Paul Moir Help please...

Couldnt find it. You can check the head by holding a steel ruler over the gasket surface at middle of head. Will the ruler touch all 4 places it passes ?? If it doesnt ( my bet ) take a couple of sheets of fine sand paper, tape it to a glass plate and carefully slide cylinder head in "8" pattern on it for some time. Be carefull to move it parallel with surface. After a little while your cylinder head is straight again, no problem. Same time take a look at you cylinders. Be sure to clean all sand from head before you put it back on with a new gasket. No big deal.

nordy · Aug 2, 2005

Re: G Dane,Paul Moir Help please...

Hello Dane, hello rosco, can you tell me the max spark advance of the 2-cyl. 35hp with full throttle ? Rosco, good luck in repairing the engine. I think a new gasket and a planed head will solve the problem. Greetings Nordy

G DANE · Aug 2, 2005

Re: G Dane,Paul Moir Help please...

Hi nordy The 1976 35 HP Rosco has had 34 deg max spark advance. They were last vintage with points ignition. My shop manual ( Clymer ) says to set the 30 Hp at 29 - 31 deg spark advance. There were no 35 hp in 1991, which is the year for my manual. I have a couple of copyes from the 35 HP manual in shop, I will try to find them and post results, unless someone else comes in first.

ross patti · Aug 3, 2005

Re: G Dane,Paul Moir Help please...

Hey,Dane.. Found out price of head gasket and thermostat today.$50 for both. So you think a bit of machining on the head and a new gasket should solve my problems? I'm prepared to throw a few bucks at the problem,but if it gets too out of hand,I'd rather just save and buy something 20 years newer. I've started the WD40 on the head bolts.Then I'll see how many I can snap off on the weekend.From there,I'll let you know what I find if I can get the head off.I love your confidence with the "no big deal" Thanks so much for all the help. P.S....a friend put this theory forward..As the engine is running better than it has for probably 15 years,the weakness in a particular component is soon found out because of the extra power/operating performance putting stress beyond what has been evident for 15yrs.This was after some drinks,but he may have a point. Thanks again...

fireman57 · Aug 3, 2005

Re: G Dane,Paul Moir Help please...

I don't subscribe to that theory, especially in your case. You know that it overheated. Either a plugged intake, clogged water jacket, ot stuck tstat was the problem. You'll know a lot more this weekend. I guess you have about two months before your spring hits don't ya? Good luck old mate and keep posting.

G DANE · Aug 3, 2005

Re: G Dane,Paul Moir Help please...

Rosco - I know the feeling you can get. My first Evinrude was a 1973 20 HP. The block was corroded from saltwater ( a weakness on this particular model ) but I got a 25 HP block from a parts motor, got it working and ran it for a season, then some ignition or whatever problem made mee get a newer motor, I put the old one in a corner in the shop where it sat for 3 years. That was when my brotherinlaw needed a motor. We changed the cranckshaft seal that was the problem and put it back to service again. This whole spring we battled with an ignition problem, which turned out to be a bad NEW condenser. Since then he put around 300 HOURS of troublefree sailing on it, 95 % at WOT !! As my old dealer friend said, Evinrudes dont wear out, they get ruined by lack of service og neglect of maintenance. He had a 56 20 HP he used every year since. If your 76 35 HP is healthy, It will serve you well for a LONG period, once you get the old bugs out. BTW Head doesnt need to be machined, just straightened on a sandpaper plate.

nordy · Aug 3, 2005

Re: G Dane,Paul Moir Help please...

Hi G Dane, I'll try the 34° spark advance on my 30 hp to see if I gain some more power from it. I only have to screw the stop bolt 4 further turns out. I think I can control the rise in combustion temperature well, because I always drive 98 RON fuel and have a larger jet in the carb for better cooling. My spark plugs' electrodes therefore usually have a mid to dark brown colour. My engine has very good performance because I've done a lot to increase the power. There is easy potential for "tuning" in the 30hp. Besides I always use the same cylinder head gasket, because I've seen that the gasket (the alu rings too) is as thick as before after removing the head. No problem to get the cylinders tight. Greetings Nordy

G DANE · Aug 3, 2005

Re: G Dane,Paul Moir Help please...

And : Take the head off before you throw $$. You can see if cylinders are badly scored, then.

G DANE · Aug 3, 2005

Re: G Dane,Paul Moir Help please...

nordy - now i'm getting corious here - what did you do to tweak performance ?? Be aware running as much rpm's as possible will help lower temperature.

nordy · Aug 3, 2005

Re: G Dane,Paul Moir Help please...

Dane, combustion temperature will rise, if you have more spark advance. An old rule says 10 degree mean an increase of 100°C. You can't solve such a problem with more revolution alone, which may help avoiding detonation a bit. It's better to have a rich air/fuel-mixture (Lambda < 0,8), which may drop temp most effectively. If you want to know about my "tuning" please let me know it. We may discuss it per E-mail. Nordy

ross patti · Aug 3, 2005

Re: G Dane,Paul Moir Help please...

Hey guys, Interesting sidetrack... Nordy,count me in with your bavarian secrets please ! As far as my drama, I'm still only spraying common penetrating spray on the bolt heads till the weekend.I'm also talking to them,telling them how nice it would be if they all came out ! .Now,when I say came out,I don't mean they announced their gay tendencies,I mean I was able to remove them. But if you think about it,they are all the" male " in the nut/bolt equation ,so who knows ??? Back to business,This sort of job would have definitely been out of my depth before iboats and especially guys like you. I'm not sucking up...well,just a little. You make it sound real simple.I will obviously post any particular problems,but what I'd love to have is a well described step-by-step of the whole process.I've got the evinrude genuine manual,but it is aimed at mechanics,not 1/4 mechanics like rosco and many others. The idea being to study them,and go into it as if I'd done it before.Second time is easy.It's the first that stumps you ! Thanks to all ...

ross patti · Aug 3, 2005

Re: G Dane,Paul Moir Help please...

Well guys.... I got all keen and tried to take a bolt off.EASY.So were the next 11. Every bolt on the head and even on the cover plate came out without any drama at all.I can't believe it . So now tomorrow afternoon will see the head removed.If you have any tips for me,now would be a great time to share them. Just glad that step one went easier than expected.And I only used a quarter can of spray. Thanks again...

fireman57 · Aug 4, 2005

Re: G Dane,Paul Moir Help please...

The hardest part is over. you got the bolts out without any of them breaking. Just check for pieces of metal in your cylinders that shouldn't be there. Check the cylinder walls for any scoring. Examine the top of the pistons. Tell everybody what you found. I think you will be surprised. I still don't think it is as bad as you think it is. Well, at least I hope it isn't.

G DANE · Aug 4, 2005

Re: G Dane,Paul Moir Help please...

nordy, I use my wifes email salg(remove)@romantiskbad.dk, but why not start a new thread here about it, I know lots asked of possibilities of gaining speed here. I once tried bending reed stops back, but it only led to a lost leaf.

ross patti · Aug 4, 2005

Re: G Dane,Paul Moir Help please...

Thanks,fireman... Your 2c is always appreciated. Yeah,I was pretty rapt to get every single bolt loose,especially after the warnings from you guys. Apart from strange bits of metal,the book also says to rip into the carbon build up. But like you said,I'll post what I find.I might even drop you an email. Thanks again....

lark2004 · Aug 4, 2005

Re: G Dane,Paul Moir Help please...

the head may be a bit stubborn to remove. Try using a rubber mallet on the side of the head to loosen it from the old head gasket.

ross patti · Aug 4, 2005

Re: G Dane,Paul Moir Help please...

Hello,lark... Fancy someone saying I've got a stubborn head !!. I'm happy to start with finesse,if that don't work,then work my way up to hammers. P.S Keep an eye on those Wests Tigers.They just might be coming at your broncs. Keep following,the fun is only starting. Thanks

ross patti · Aug 4, 2005

Re: G Dane,Paul Moir Help please...

Well,guys.... Took the head off today. It came off easy.The head gasket is intact.There was no foreign lumps of metal in the cylinder. The cylinders seemed pretty good,with some scoring at one point. The gasket showed signs of poor seal at the middle part ,the "waist" between the two cyls,and towards this point. When I touched the head on the sandpaper on glass,it also showed signs of being low in the same area.Remember,the gasket was not blown,just carbon/discoloured where I suspect it was leaking from. I gave the impeller and pump set-up a closer inspection.The impeller itself seems intact with no signs of stress.The housing is warped. The connecting tube with grommet for the water pipe is not perpendicular.The top of this tube shows signs of heating,near the grommet.The spacer tube around the drive shaft is melted where it sits over the impeller housing. The pistons showed no signs of slop in the cyl. The hose leading to the tell tale is clear. I shoved the hose up the water tube {with the lower unit off},and water came out of where it should.BUT,I still need to check the water pumping thru the impeller,when I get this head back on. Allright guys....I think I covered everything I did Over to you experts !! THANKYOU..

G DANE · Aug 5, 2005

Re: G Dane,Paul Moir Help please...

Rosco - The thermostat is located in the head under the water jacket cover. Even if the thermostat was stuck, water will flow thru exhaust cooling and exit thru tell-tale. The thermostat in head stops water from exiting from block, but it will still flow thru exhaust water jacket on side of motor.

ross patti · Aug 5, 2005

Re: G Dane,Paul Moir Help please...

Dane, I forgot to mention ...there was NO thermostat. I'm still trying to figure what caused the overheat. Could the impeller fin assembly{the rubber part}slip on the metal"hub" centre? The head bolts came off nice and easy because they had a grease all thru the threads. They also seemed to be tourqued lightly.Not much more than a spark plug.This may not have helped. I'll hone the head down tomorrow,change the gasket and hope that fixes the compression. But I'm still buggered as to what caused the o'heating. Thanks again...

G Dane,Paul Moir Help please...

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