G Dane,Paul Moir Help please...

[nordy]

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

Hello rosco,<br /><br />it definitively has a thermostat !<br /><br />It is under the thin cover plate.<br />You must remove this and you will see.<br /><br />If the thermostat is calcified it normally won't open anymore.<br />It only will open - the whole valve will move against a spring then - when water pressure exceeds a certain level.<br />This is a failsafe function.<br /><br />It's a hard job to remove the cover.<br />Be careful the plate won't get broken.<br /><br />Nordy

 

[G DANE]

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

What Nordy says, the thermostat should be located inside cylinder head, behind the "bubble" in upper end of the cover on sparkplug side of cylinder head. Did you remove this cover without finding the thermostate ??

 

[G DANE]

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

Rosco, I had a couple apart that had small scores next to exhaust ports - didnt harm anything, but was mostly visiable, hardly feelable. I dont think your small scores means anything. Just get the warp corrected, thermostat changed and a new gasket in. Remember to torque right, in cross pattern, starting from mid center, working your way out.

 

[ross patti]

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

Hey guys...<br /> The thermostat had been removed some time ago.When I got to the cover plate,there was no t'stat.When I get a new one,should I go with the manual recommended temp., or do you have a better temp range ?.<br /> As I mentioned before,the last guy to do the head used some grease of some sort on all the bolt threads.They went in and out like...easy.The cover plate came off easy ,too.<br /> So,assuming the honing of the head will fix the compression,I still have the question of why did it overheat in the first place ??<br /> I will take the impeller & housing to a mechanic and get his opinion.<br /> To check the rings,I guess I have some more pulling down to do ???.<br /> There was some carbon build-up in the piston recesses of the head,but a little engine tune and a brush soon fixed that. We don't have seafoam out here,but now I can see what you guys have been raving about !<br /> The cylinders have a black build -up on them,but when it's back together,the first thing I'll do is hit it with the engine tune.<br /> Dane,my cylinder is also scored near the exhaust ports,too.<br /> Thanks again.. If anyone has an opinion on the impeller,or any other factor leading to the overheating,don't be shy...

 

[aanda6]

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

Rosco, I live in Melb and couldn't find sea foam either. Found a guy with Chem-Tune, does a great job.Have heaps and can send you some to Sydney if you would like to try.

 

[G DANE]

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

Well, if the head gasket blows, exhaust gases will blow all cooling water out from cylinderhead and fill entire cooling system with steam instead of water. Could have been the other way round, blown gasket caused overheat, instead of overheat causing blown gasket. There was another issue with the early models. Salt and corrosion build up around the rubber grommet, sealing copper cooling water tube in midsection to exhaust housing just below poverhead base. Opening gets smaller. Repair of this requires powerhead to be pulled and bore for grommet cleaned up, grommet reinstalled. If there is full flow thru copper tube and block, you shouldnt have this problem that usually is from salt water use, and no flushing. ( I use in salt water, and NEVER remember to flush either.

 

[G DANE]

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

BTW there should be 2 "water deflectors" which is a small piece of rubber looking like gas hose, squized in between castings in block. They have to be in place to ensure correct water flow in block/head.

 

[ross patti]

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

Hey guys...<br /> Andrew,thanks for dropping in.Yeah,mine is actually the Mercury product.My OMC dealer couldn't get stock of the Johnson stuff,so he had to alter his standards and get the opposition stuff in.But it still works brilliantly.<br /> Dane,yes,the deflectors are in place.I "artificially" flushed the motor by putting the garden hose onto the water tube that comes from the powerhead.Water freely spouted from the pisser and exhaust vent holes.<br /> Now to the head gasket.The gasket shows evidence of being breached across the two cylinders.<br /> On the head side of gasket,there were carbon stains there.<br /> On the block side of gasket,it's worse.<br /> BUT,the gasket could be cleaned up and you probably would'nt know it's gone. There is no major damage to it,but the motor was not run for more than a few minutes after the cooking started.Does the gasket need to be blown apart before it pumps exhaust into the water chambers,or will it do it from a smaller leak ?.<br /> I think the honing of the head,and a new gasket should fix the compression.It may even raise it from before{122}<br /> Gonna do the head tomorrow,and get the impeller looked at on Monday.<br /><br /> Thanks again for the help...

 

[nordy]

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

Hello rosco,<br /><br />the missing thermostat leads to a lower water temperature.<br />Especially the warm-up period will take longer, it's no good idea.<br />Put a new one in.<br /><br />Don't think about the impeller too much.<br />Don't hesitate to build a new one in.<br /><br />I had curious overheating with my 30hp too, since I reniewed it, there are no problems.<br />Flush the whole cooling system intensely.<br /><br />Nordy

 

[G DANE]

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

Rosco<br /><br />The pressure in the atmosphere is 1.00 bar/14,7 PSI + cooling water pressure 10 - 14 psi at wot. Compression of the 35 HP is around 1:8,5 which gives 122 PSI + combustion expansion which is around 5 times. The enormous pressure will make even the slightest leak press any cooling water away. As soon as the gasket starts leaking, the heat from hot gasses will start to soften gasket material. The reinforced material usually makes gaskets stay in place, though. If there is carbon on the steel rings its evidence of leak. Remember when you have ran motor first time efter new gasket to retorque head to specs, or it can fail again.

 

[ross patti]

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

Hey guys...<br /> Nordy,thanks for keeping up with me.I will definitely put the thermostat in place.OMC recommends 145f.Unless someone has a real good reason to alter the temp.range,that's what I'll go for.While I'm at the parts shop,I'll get the impeller & housing.<br /> Dane, Your description of a stuffed gasket makes me think you snuck over here and had a look at mine !! Yes,there was carbon on the steel rings. And as I said earlier,the block side of the gasket has carbon and a bit of oil/fuel spray as well.<br /> The genius who did the head before,decided to ignore the " DO NOT USE SEALER " warning clearly printed on the gasket. At least he resisted putting sealer in the thin strip between the cylinders.Which left a gap at that point.And you know the rest.!!!<br /> As for torquing the head bolts,the manual says 14-16 ft lbs.Now this might prove I'm no mechanic,but isn't that really light ??<br /> I've got the head 95 % perfect.Just need to smooth off a little carbon staining around the middle part of the "figure 8 ".<br /> Thanks again guys,I'll go spend some $$ at the parts shop,and let you know the results.

 

[nordy]

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

Hi Rosco,<br /><br />my opinion on torquing the head bolts:<br /><br />15 ftlbs => 20 Nm is indeed too light.<br /><br />You must take in account the gasket cylinder rings are quite hard.<br />Tightening always comes from compressing the gasket and especially the rings a bit.<br />I realised the rings after use were as thick as in new condition.<br />So it's better to torque the bolts more heavily.<br /><br />I usually torque them as heavy as the spark plugs, I apply around 30 Nm not using a torque meter but relying on sense which works perfektly.<br /><br />By the way, as longs as the gasket looks good I won't use a new one.<br /><br />Greetings Nordy

 

[ross patti]

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

Hi Nordy...<br /> I think I'll take the advice on the torque of bolts.Thanks.<br /> As far as the gasket goes,this one is a bit ratty,And for only $22,I'd rather put in a good one.The previous person to pull the head down used a sealant of some sort on it .The heat has sort of glazed the water cover side of gasket in a figure 8 pattern,and chewed the gasket surface on the other side,where the sealant was.<br /> Thanks for all your help..

 

[nordy]

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

Rosco, the price of the gasket here in Germany is much higher.<br />It costs around 35 Euros which is nearly 3 times your price.<br /><br />Nordy

 

[G DANE]

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

ALWAYS use a new gasket, or you'r asking for it to leak.

 

[ross patti]

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

Well,for once it's cheaper in Australia.<br /> So Dane,you think the gasket caused the overheating?<br /> I'll renew the parts,and see how we go. <br /> Thanks again...

 

[lark2004]

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

Geez Rosco, where did you get the head gasket? <br />Mine cost $52.00 !

 

[ross patti]

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

G'day lark.<br /> The gasket is actually $27,not 22. But still....<br /> I get most of my parts from a place called Moby Marine here in Sydney.Their number is 02 9153 6030.Just spoke to them now and they said they ship overnight across the country.<br /> Give them a call.

 

[ross patti]

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

One more question...<br /> Do you think I can do the sandpaper on glass trick for the impeller housing ?. I have the hard plastic one.<br /> I don't feel like forking out $160 on a new kit if I don't have to.My impeller is perfect.The housing is slightly warped.I also need a new spacer tube.<br /> Thanks guys...

 

[aanda6]

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

Rosco, sorry to drop in again, Let you know Golden Seal in Mordiallic sell the original impeller housing for $45. Might be worth a try to see if he has your model. Otherwise do what I did and order it from the US, save a s!#@load