Inexpensive engine alignment tool- DIY

[Paul Bretz]

So we got tight, shaft and rim job all in the same paragraph. Ha.

 

[soccerdad]

The sleeve needs to be tight or it won't really be that accurate. But it has been a long time since I used it. I know I did not have to open it up any or resize the shaft.

 

[rgardner928]

The sleeve needs to be tight or it won't really be that accurate. But it has been a long time since I used it. I know I did not have to open it up any or resize the shaft.

when measuring the length of your shaft. Did you add the rubber bumpers to the ends into that length? Or did you do it without them?

 

[IDoSeaDoo]

Bravo! I think this is a great alternative. The question is how much would it cost to have this steel milled at a machine shop for us rubes who don't have access to such glorious tools. Can you buy pipe already the right diameter?

 

[rgardner928]

Bravo! I think this is a great alternative. The question is how much would it cost to have this steel milled at a machine shop for us rubes who don't have access to such glorious tools. Can you buy pipe already the right diameter?

If you scroll up. Both of your questions are answered in the forum several times.

 

[highcam]

Sorry to revive an old thread however, I took inspiration from this thread and created what I think is equivalent to the SBT or OEM engine alignment tool. So thanks to OP!

The shaft for the jetpump is 3/4" -- at least that is what shaft size the needle bearings are designed for.

I purchased a 3/4" annealed tool steel rod from McMaster ( McMaster-Carr )

Annealed is important, as a hardened tool steel rod will be very difficult to machine.

I measured the length required and cut off of the extra. I then turned a 3-4" section of the end to 18mm.

I have a disassembled jet pump which I then mount to the boat. I slide the rod into the jet pump, so that the 3/4" section is supported by the needle bearings. The 18mm portion then engages with the output flange of the engine.

The jet pump which is used for the 951 will work. It is my belief that if you have the engine out, it is a great time to go through the jet pump any way.

With this method I believe you can achieve a very precise fit, equal or close to that of the $300 engine alignment tools.

 

[soccerdad]

Buying 18 shafting saves you the trouble of machining, but you way works fine. To report back, that motor has been in the ski for several years now. I am still on the same carbon ring and no cavitation, no other problems. So it is still working well for me.

 

[Paul Bretz]

Sorry to revive an old thread however, I took inspiration from this thread and created what I think is equivalent to the SBT or OEM engine alignment tool. So thanks to OP!

The shaft for the jetpump is 3/4" -- at least that is what shaft size the needle bearings are designed for.

I purchased a 3/4" annealed tool steel rod from McMaster ( McMaster-Carr )

Annealed is important, as a hardened tool steel rod will be very difficult to machine.

I measured the length required and cut off of the extra. I then turned a 3-4" section of the end to 18mm.

I have a disassembled jet pump which I then mount to the boat. I slide the rod into the jet pump, so that the 3/4" section is supported by the needle bearings. The 18mm portion then engages with the output flange of the engine.

The jet pump which is used for the 951 will work. It is my belief that if you have the engine out, it is a great time to go through the jet pump any way.

With this method I believe you can achieve a very precise fit, equal or close to that of the $300 engine alignment tools.

Thats exactly what i have done except i used an aluminum rod from mcmaster and i have an abundance of pumps to sacrifice for alignment purposes

 

[soccerdad]

Sorry, I missed the point. The 3/4" material is the logical way to go if you are using a gutted pump. Straight 18mm is easier if you are using a built pump. Glad this helped for inspiration. You got to do the perspiration

 

[Paul Bretz]

Sorry, I missed the point. The 3/4" material is the logical way to go if you are using a gutted pump. Straight 18mm is easier if you are using a built pump. Glad this helped for inspiration. You got to do the perspiration

I agree. But in the end it works very well. I machined both sides of the rod down. One for good splines in pto and other for splines that are a little worn. So different sizes machined down on each end. I mainly did mine for a 951 swap in a 96xp