what to expect

[mrfixitman40]

Hello all I am gonna start on a project and rebuild my 1964 75 horse . I got new pistons .020 oversized, ring, gaskets and waterpump. I would like to make it so next year when i go out i know nothing can go wrong unless it is my fault. Is there anything else i should do other than carbs and tune up stuff to give myself more peace of mind ? Anything in the lower unit? would it be a good idea to put the tell tail in while it is apart? I am gonna be doing this in my living room while i am off work for knee surgery so I want to try to get everything gathered up ahead of time i am going to pull it apart before and have the machine work done so i will be reassembling while i am stuck at home. any input would be great . The pistons are wiseco with file fit rings and supposedly 10.2:1 compression what is the stock compression? will there be a performance improvement over a stock rering ? What is the best reed valves to use and where is the best place to find them ? Thank you in advance !!
John
PS this is an electric shift.

 

[HighTrim]

Re: what to expect

When was the impeller last dont, if the lower unit is down I would definately service the water pump. Dhadly is very knowledgeable in motor rebuilds, may want to speak with him.

 

[mrfixitman40]

Re: what to expect

got a new water pump for it since it will be apart . I have never done an outboard but have been reading my manual in my spare time.

 

[HighTrim]

Re: what to expect

the manual along with this forum all 2 very good resources to have.

 

[Chris1956]

Re: what to expect

I would be very surprized if the compression ratio is 10::1. Most 2 cycle motors are low compression, and that vintage Johnnyrude were quite low compression.

Go thru the ign. system and make sure the points are square and clean, the wires are clean and tight and the coil doesn't have any cracks. Clean the fuel pump and put in a new filter if it is falling apart. Check the alternator and rectifier for clean connections and proper operation. You can use an ohmmeter to test the rectifier. Check the starting circuit and clean up it contacts.

Have fun while you heal!

 

[Chinewalker]

Re: what to expect

Those V4s were quite low compression ratios - probably in the neighborhood of 5:1 or 6:1. Certainly not 10:1 - that'd be a bear - and you'd have to run Av Gas to keep it from cooking... if you could get it to turn over in the first place!
- Scott

 

[mrfixitman40]

Re: what to expect

i was figuring that was high but that was what they told me. i will actually check the true compression when i am assembling it was hoping to get ideas . I am gonna call wiseco with the part number tonight and see what they say plus make sure they are the correct pistons . I did compare the bore to the book thats how i found out they were correct as .020 over. someone mentioned the fuel pump is there a replacement pump or just a rebuild kit made.

 

[HighTrim]

Re: what to expect

This is the kit you will need.

http://www.iboats.com/mall/partfind...gd_poid=109271&gd_row=84&**********=395092348

 

[F_R]

Re: what to expect

10:1 would be racing stuff. Definately calls for high octane gas and possible timing tweaking. Would be like setting up a race engine, special skills and knowledge required.

Make sure that lower unit has good seals. Water intrusion is a major problem in any motor, but even moreso in the electric shift. And be sure you use OMC/BRP Premium blend oil in the lower.

Good luck with the knees. I had total joint replacements in both knees two years ago. One of the best things I ever did. Hint: If you are getting replacements, get a copy of the exercises from your doc and start doing them now!

 

[mrfixitman40]

Re: what to expect

ok thanks for the info i will let you guys know tomorrow what wiseco says. i was gonna try to reseal the lower unit also is there anything in the lower that wears out i didn't get any water out when i drained it but a very faint metallic in it. any ideas ?
They aren't sure what they are gonna do hopefully at this point with the knees starting off with the scope and gonna decide from there. thank you

 

[HighTrim]

Re: what to expect

Very faint metallic is normal, nature of the beast. I dont usually like to throw time and money into something that isnt broken, but if you get bored you could always do the seals in the lower unit, and then the ones in mine when you are done!! Fr is the man you want to befriend owning that vintage motor, he knows his stuff so pay attention! lol

 

[mrfixitman40]

Re: what to expect

ok the pistons are 8 to 1 advertised they say actual will probably be mid 7:1 so should be fine they are correct for the motor but haven't been made since 83 so they have been sitting for awhile .
I would usually agree with you high trim but i am shooting for a trouble free year next year when we get out on the water.
Thank you all for the input so far