correct prop replacement for AQ270 outdrive-gctid385078

[Guest]

I am having the stock prop fixed this week but want to get on the water this holiday weekend.

I have a brand new, SMC 270 short hub alum. 3 blade prop I bought as a spare years ago.

Problem is when I fit it on the outdrive there is a slight space between the prop and the zinc ring, like the recessed back part of the prop hub isn't quite deep enough to fit snug up against the ring. The setup includes the typical, cone/spacer/prop/shorter line cutter ring.

Everything tightens down and it spins fine except for this extra space compared to the stock prop.

Is it ok to run it like this?

Thanks.

Joe

[2850Bounty]

Joe, the 250, 270 and 275 prop shafts all use the short spacer/line cutter.

The 280, 285, 290 and SP prop shafts all require the long spacer/line cutter.

This nets the same amount of propeller shaft for either style lower unit.

Since your prop is the std hub, all should work with the full spinner.

Since the 250 and the 270 prop shafts are not drilled and threaded for the center spinner keeper bolt, the SS locking tab must be used and folded into one or two castlated areas in the spinner.

There will be just enough prop shaft protruding through the propeller hub for this locking tab keeper to index the shaft splines.

There is only one ring anode that fits the 270 lower unit, and only one spacer/line cutter.

If this prop is correct for the Volvo Penta drive, I can't quite explain the gap between the ring anode and propeller hub.

It may not be an issue. Give it a try.

.

[Guest]

Since the 250 and the 270 prop shafts are not drilled and threaded for the center spinner keeper bolt, the SS locking tab must be used and folded into one or two castlated areas in the spinner.

There will be just enough prop shaft protruding through the propeller hub for this locking tab keeper to index the shaft splines.

Rick this 270 prop shaft does have the drilled/threaded hole for the center bolt and does not have the SS locking tab.

Both the standard prop and this new one line up so that the cone, etc. fits correctly on the shaft, the splines all line up and it snugs up tightly with the bolt. Here is a pic of the space I am referring to.

Joe

Attached files [img]/media/kunena/attachments/vb/688659=28092-prop1.jpg[/img] [img]/media/kunena/attachments/vb/688659=28093-prop2.jpg[/img]

[2850Bounty]

SeaDog wrote:
Since the 250 and the 270 prop shafts are not drilled and threaded for the center spinner keeper bolt, the SS locking tab must be used and folded into one or two castlated areas in the spinner.

There will be just enough prop shaft protruding through the propeller hub for this locking tab keeper to index the shaft splines.

Rick this 270 prop shaft does have the drilled/threaded hole for the center bolt and does not have the SS locking tab.

Both the standard prop and this new one line up so that the cone, etc. fits correctly on the shaft, the splines all line up and it snugs up tightly with the bolt. Here is a pic of the space I am referring to.

Joe, if your prop shaft is internally threaded for the keeper bolt, and if your helmet pin is the double bolt style, and if your exhaust outlet housing is placed further AFT from the 270 style.........., then you DO NOT have a 270.

Instead, you will have the 275 drive..... of which was commonly used in your year model.

With the 275, you will use the short spacer/liner cutter! The long spacer/line cutter will NOT work!

You will also use either the SS tab washer, and/or the single spinner or the 2 pc spinner with the locking bolt with the standard hub prop.

This is due to the standard hub propeller length vs the net shaft length dimension.

IOW, this becomes an Either/Or scenario.

• STD Prop hub without the SS tab washer and with the plastic washer and with the center locking bolt.
• STD Prop hub with the SS tab washer, and without the center locking bolt........... or use both.

If you install a long hub propeller, then you'll be using the AFT-most section ONLY of the 2 pc spinner, AND the center locking bolt.

There are no alternates to this.

.

[Guest]

Thanks for that clarification Rick.

I will check the spacer-line cutter tonite but I am pretty sure it is the short one.

That little space between the hub of the prop and the zinc is caused by this spacer-line cutter even though it is the short one.

I don't think that will hurt anything will it, so long as everything is tight and snug on the shaft and it is without any wobble, etc. and everything fits in correct position on the shaft to the exact shaft length.

Joe

[2850Bounty]

Since your prop shaft is internally threaded, this can now be changed to:

1985 Capri BR 1950, "SeaDog"

AQ125a/275

Unless only the shaft was changed at one time!

.

[dktool]

[img]/media/kunena/attachments/vb/688779=28104-prop1.jpg[/img]On my 270 (other boat) I have the same step on the rear of the prop and a small gap like you do.I turned an aluminum ring on the lathe that is a press fit on to the prop and the O.D. is the prop hub dia.It fills the gap and makes a smooth flow path transition from the gear case to the prop.

[Guest]

Rick that drive helmet does have the 2 pin arrangement so that confirms the 275 model. And the line cutter-spacer is the short type as far as I can tell.

Dean I like that alum ring idea, but I don't have the tools or skills to fashion something like that unfortunately.

I am going to try it like it is tomorrow and see how it goes. No wobble at all in this setup and every part fits where it should except for that small space as shown in the pics.

Joe

[2850Bounty]

Joe, I see that you changed your signature!

FYI... just AFT of the helmet attachment point will be a PZNR # tag plate attached to the transmission.

[Guest]

SeaDog wrote:
Thanks for that clarification Rick.

I will check the spacer-line cutter tonite but I am pretty sure it is the short one.

That little space between the hub of the prop and the zinc is caused by this spacer-line cutter even though it is the short one.

I don't think that will hurt anything will it, so long as everything is tight and snug on the shaft and it is without any wobble, etc. and everything fits in correct position on the shaft to the exact shaft length.

Joe

Since the spacer-line cutter is AFTER (aft) of the prop and anode gap, it can't be the cause. It's the new prop. You didn't mention if you had the gap with the stock prop, but I'm inferring you didn't. Some measurements with a set of calipers should solve the mystery.

I have used Solas Amita props as replacements for the stock Volvo props. Never a problem. Hustler Marine (Ebay store, and across town for me) has good prices, but available everywhere. Solas gets good reviews in articles I've read on prop tests.

I also had the same situation/identification problem. Center shaft bolt, but always thought they didn't use 275's on Bayliners in 1983. Seems the 270 has the tabs and cutter built into the cone nut, according to my VP 270 Workshop Manual pics. (not sure if this is "always") There may be a shorter cone nut and spacer combo for the 270. Just a 2 pc affair. Dunno, but not pictured in my manual.

[2850Bounty]

FYI, there were only three styles of spinners available for the s/p drives.

the 1 pc with no center locking bolt bore..... and will be castellated for the tab washer.

the 1 pc with the center locking bolt bore.... and I believe that most are also castellated.

the 2 pc spinner, of which will always have the center locking bolt bore, and the FWD section will be castellated.

The later one is basically a one-fits-all.

The only time that the AFT-most section of the 2 pc spinner is used, will be for the long hub propellers. And this only works on prop shafts that are internally threaded for the keeper bolt. Otherwise, there is no means of locking the spinner, unless tie wire was somehow used.

.

[Guest]

Finally got the boat in the water yesterday. Good shakedown day on the lake.

That prop didn't give me any problems at all even with the small space.

Now I am curious though. Anyone have the height dimension of the "short spacer-line cutter" so I can compare mine to that?

Joe

[2850Bounty]

Joe, with the correct spacer/line cutter, the prop will fit your 270 shaft.

You cannot mistake the two spacers!

Here is a short spacer used on all 250/270/275 lower unit prop shafts..... regardless of which style prop hub.



Here is a long spacer used on all 280/285/290/SP lower unit prop shafts...... and again, regardless of which style prop hub.



You can see that there is a considerable difference in length.

This is for any AQ series single prop drive owner:

NOTE: when we do a search for the spacer/line cutters, we will no doubt see a referance to the prop hub length.

This is a misnomer.

The spacer/line cutter is proprietary to the prop shaft.... NOT THE PROP HUB (long or short hub)!

This is a common mistake that even the Volvo Penta parts counter people, AND the on-line companies make.

The long hub prop -vs- the short hub prop has ZERO to do with the spacer/line cutter.

Whether or not the prop shaft is internally threaded for the 2 pc spinner center keeper bolt, determines whether or not the long hub propeller can be used.

Repeat: the spacer/line cutter is proprietary to the prop shaft.... not the propeller hub itself.

The long hub prop -vs- the short hub prop has ZERO to do with the spacer/line cutter.



In the two images below, you'll see the lengths of both prop shaft styles being shown (the 250/270/275 and the 280/285/290/SP).

The shaft that appears to be "short", is the 250/270/275 shaft.

The shaft that appears to be "long" is the 280/285/290/SP shaft.

All propeller shafts (250/270/275 and 280/285/290/SP) net the same identical exposed shaft and spline length when the correct spacer/line cutter is used.

IOW, if you were to place the correct spacer onto either shaft, the Net Length is equal.

Attached files [img]/media/kunena/attachments/vb/694200=28610-Prop shaft 250 thru 275 dimensions.jpg[/img] [img]/media/kunena/attachments/vb/694200=28611-Prop shaft 280 thru SP dimensions.jpg[/img]

[Guest]

Thanks Rick for the explanation.

This replacement prop is working fine even with the space, so I will just continue with it until I get the rebuilt prop back and then will closely inspect that spacer/line cutter.

Joe

[Guest]

The new prop runs fine, except that after only 3 outings, and about 3 wks at the dock the new prop is developing signs similar to the the old one-

looks like eroded marks on the surface of the blades. It didn't hit anything, this looks like a galvanic process to me. Any ideas?

Attached files [img]/media/kunena/attachments/vb/698330=29090-propbubbles.jpg[/img]