1978 Evinrude 175hp Crossflow - 30% blow-by

[Breilly]

Hello and thank you for reviewing my post.

To start I need help which is why I am on the forums. I have a 1978 Evinrude 175hp outboard engine. I have owned it for 4 years and it has always ran well up until this year. I was idling while trolling for fish and it died. I could get it to start and idle but it would putter out once I put it into gear. I always mix 50/1 oil with the gas.

I got added Sea Foam to the fuel and replaced all the plugs and could get it to run in the driveway however when put in water it wouldn't start.

I recently took it into the marina and they told me the compression was off on #1 and #2 pistons with 30% blow-by. They said that the rings were gone from those two pistons no-where to be found. They also said that all the pistons failed the leak in test. So they proceeded to tell me I would need a new powerhead and that it wouldn't be worth the money.

I am hoping to be able to fix it since I don't have the money to buy a new motor or boat. They said that replacing just one part wouldn't be worth it and a complete overhaul is the only solution. I have read other forums of people not recommending this since "new parts don't sit well on old gear". I am looking for any help and advice. I have found a rebuilding kit including bearings for $750 but I don't know if I could handle this task or not. Although I do own the shop manual for the motor. Do I need to do the whole engine? Could I do it myself?

Thanks,

Breilly

 

[ezeke]

Re: 1978 Evinrude 175hp Crossflow - 30% blow-by

I think that the only way to tell how severe the damage is would be to remove the cylinder heads and inspect. You could get some idea of the condition of the rings by removing the bypass covers.

Did the service department give you the compression readings?

If you do the work yourself, you might be able to get by with around $1,000 plus boring cost, if there are no surprises. You will need to pull the powerhead and disassemble it.

If you follow the manual and take your time, you can probably do most of a rebuild yourself. I would highly recommend that you find someone with excellent references to take the block to for whatever work is needed. Be sure to wait for the measurements before ordering new rings and pistons.
If you have anything but an experienced outboard engine shop work on the block, you will probably be disappointed in the results.

 

[mikesea]

Re: 1978 Evinrude 175hp Crossflow - 30% blow-by

Start by pulling the heads off and see what the visual wear is on the cyl walls.The right way to rebuild is bore all cylinders and put 6 new piston kits in to the next oversize that a bore job will straiten the bore to.Usually goes in ten thousands ,aftermarket will sell pistons to 66 thousands over.As ezeke said a good outboard machine shop is important.I know a great one in Key Largo Fl.Unless your eng is very good rest of the way around,you might THINK ABOUT putting a few more nickles toward a decent used looper engine in the 175 to 225 range.Only because they are truly the rated HP and have more power.Is your lowerunit in good shape ,your TNTilt,your lowerunit wil interchange with many other engines as well as loopers ,so you would have a spare lower,However ,if you want to rebuild,and know your way around a toolbox,you can do it.Do you run in fresh or saltwater.Because,tearing down an old saltwater eng can be a bear,especially pulling the powerhead.If you choose to do so,be sure to have a torch to help loosen stuck bolts,also before you start,come back and ask for some hints on getting stuck bolts out BEFORE you break them.

 

[Breilly]

Re: 1978 Evinrude 175hp Crossflow - 30% blow-by

Thanks for the advice.

I am running in fresh water so hopefully no stuck bolts. I am in northwestern Wisconsin, Eau Claire to be exact. I am not sure who to go to for the block and for the bore or even what to look for when I take the heads off. I can call the shop for the measurements on the compression and will let you know. Otherwise I am not sure about the lower unit. I really wouldn't mind getting a new engine if I could find one cheap enough but I have never heard of looper?

Also what do you think of these companies that you can send the engine to and they will rebuild it with a guarantee? i.e. http://www.tenkillermarine.com/boatparts/powerhead.asp or buying a new one all together do you think that would be a better idea i.e. http://www.boatmotors.com/motorparts/index.cgi?pid=6512&flag=2&hp=175&year=1978&state=wi ?

I am quite a beginner so I will need to know what to look for I can probably get it apart with the manual and my tools but what to look for as far as damage I am not sure.

Thanks,

Breilly