Changing out a 912 80 HP in a model IV

[kmach]

Why not use your old oil tank ?

[Wheels]

The old tanks and new tanks are all the same hight. The Model IV round cowl had the tank shortened due to the tight space of the cowl. It reduces the oil quantity a minuscule amount.
I want to use the new tank because it has an upgraded hose connection to A/N fittings and I like the fact that the inlet and outlet ports are on the lid. It makes identifying a crack or failure easy and and easier fix than pulling the tank.
It looks like I will need to get longer plug wires and sheaths to move the CDI but I agree, moving it is the only option for lifespan of the part. Here is a picture of the tank and you can see that I need to shorten the rest of the hardware associated with the tank.

[Slyfox]

when I changed out my engine, I sent the tank to John and he fixed it up to the right height for me. I also updated to the new motor mount and new muffler. once I had everything put together on the new motor mount and mounts I went to the airport and swapped out engines in about an hour. easy very easy.

[Wheels]

I finished the tank tonight. It took about an hour to trim the extra length from the intake tube and trim the screen. Then I cleaned everything to make sure there was no metal shavings or screen material where it shouldn't be. I'll re organize the spider tomorrow for a good position on top of the engine for the tank.

[Guy Buchanan]

2. I moved my CDI to the upper right motor mount. (See photos.)
3. I moved the expansion tank forward by rotating the head water outlets, replacing one of the expansion tank outlets with an elbow by brazing on a Rotax water pump elbow, and replacing all the tubing.
4. I did the normal tank mods.

In addition, you may find the new starter runs into your firewall. I machined off the lugs on the back of the starter and made a recess in my firewall. (See photo.)

[Slyfox]

I finished the tank tonight. It took about an hour to trim the extra length from the intake tube...

you never did say what engine you were putting in. uls has the bigger starter yes, you need to bang the firewall in a little or something. also take the cover off your old water pump and put it on the new motor, the hoses will work out better if you do. get that cdi yes on the motor mount, all things will work out for this, all wires and stuff.

[Slyfox]

now, just a heads up. I don't know if you have the newer mount or the old one that is 95 vintage. but the newer mounts have a thicker wall. the old mounts use to break all the time. I had one, I changed it over when I put in my new 912uls.

[Wheels]

The new engine is an 80 HP Rotax just like the old one. The mount is the new style. I think your right about the water pump cover. I'll look into it.