82 evinrude 150hp rebuild question

[cb950]

I have an evinrude that has 75psi in each cylinder, and would die under load. I took off the heads and there is play in the pistons. I am in the process of taking the engine apart to replace the rings (and pistons if necessary). my question is, <br /><br />I have removed the carbs, and the manifold behind them, and there is another piece in between me and the cylinders. I have removed all the bolts, and it isn't coming off. do i need to take off the flywheel to get to the piston rods? I think there might be bolts underneath the flywheel.

 

[Dhadley]

Re: 82 evinrude 150hp rebuild question

I'm not sure it needs to come apart but if youre sure thats what you want to do you have to remove the powerhead from the midsection to get to the upper and lower main bearing cap bolts.<br /><br />An OE manual will be of great help.

 

[cb950]

Re: 82 evinrude 150hp rebuild question

uh oh, i guess that is why my mechanic cringed when i asked him how hard the rebuild was going to be. I originally was planning on taking the powerhead off, but when i tried to take off the bolts, the second one broke without turning, so i figured i would try to get to it without taking the powerhead off. any suggestions?

 

[cb950]

Re: 82 evinrude 150hp rebuild question

i will order the manual, i should have done that in the first place.

 

[Dhadley]

Re: 82 evinrude 150hp rebuild question

My suggestion would be to re-evaluate if it does indeed need to come apart.

 

[cb950]

Re: 82 evinrude 150hp rebuild question

what else would cause an engine to die under load, but start right up and run fine when its not in gear? the carbs look clean.

 

[G DANE]

Re: 82 evinrude 150hp rebuild question

Synck and linck out of proper setting. It probably needs a decarb too. <br /><br />Carbs can easily look clean, without being so, too. Ignition can be weak on a cylinder or bank.<br /><br />Gauge can be reading low too.<br /><br />All crossflows I had apart had an amount of the top piston play, some times scaring, compared to a 4 stroke. These piston tops expand a lot when heating up. The rings seal if they are free moving.<br /><br />That all cylinders wear down to the point where the motor is non serviceable, at the same time without difference, is so rare it almost belongs in a museum.

 

[G DANE]

Re: 82 evinrude 150hp rebuild question

BTW If it fires right up and iddles, if may only need a decarb and tune-up.<br /><br />The part you mention is the lower cranckcase half. Powerhead must be pulled from midsection before you can part it. Upper and lower bearing carrier and midsection adapter must be off the powerhead before it can be seperated. Be carefull you dont break anything. As Dhadley mentiones you might be heading into a lot of unneccesary work. Some of the V6 crossflows had lowcompression headgaskets to make them run better on low octane gas.

 

[cb950]

Re: 82 evinrude 150hp rebuild question

i would be extremely happy if it wasn't in need of a rebuild. It seems like every mechanic i talk to in person that hears it has 75 psi in 5 cylinders, and 80 in one, cringes, and thinks it needs a rebuild. <br />What kills me is that the manual doesn't even define good compression, readings, so i can only go by what i hear. If you guys really think that it is something else, I will put it back together, and try to troubleshoot elswhere. I would rather it not be the piston rings, trust me.<br /><br />thanks for the help so far!

 

[cb950]

Re: 82 evinrude 150hp rebuild question

 

[G DANE]

Re: 82 evinrude 150hp rebuild question

Try the gauge on something else.

 

[cb950]

Re: 82 evinrude 150hp rebuild question

I went out and bought my own new guage, so i am going to put the engine back together, re-test it, and hopefully find the problem elswhere.<br />we'll see after the weekend.

 

[G DANE]

Re: 82 evinrude 150hp rebuild question

Look at the discription of compression on this motor for sale, compared to yours : http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=2485076631&category=50439

 

[cb950]

Re: 82 evinrude 150hp rebuild question

i put it back together. it starts right up, and after cleaning the plugs, it ran awesome....for about 30 seconds. the plugs are getting fouled up. i think that is the problem. i tried new gas. the choke isn't stuck, and the carbs aren't adjustable. what else could it be?<br /><br />i think i am going to take apart a carb, and look inside.

 

[cb950]

Re: 82 evinrude 150hp rebuild question

non adjustable carb

 

[G DANE]

Re: 82 evinrude 150hp rebuild question

Did you clean and rebuild the carbs ?? I think yours have airjets, and if they are dirty, it will run rich. Do a sync and linck, following the manual. After it starts to warm up, plugs will be wet at iddle, but it will run anyway. Sounds like it needs carb cleaning and sync and linck. Test spark by letting all 4 jump 5/16" gap to ground crancking, after problem has appeared, you may have a faulty coil. Never leave a plug in the air while crancking, without grounding threads, or current may build up in pack and burn it. Also check float setting.