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3.0 Alpha 1 Gen 2 rpms increase prior to gear engagement

J

jon_allen

Regular Contributor
Hi All

I have 2005 3.0 Alpha 1 gen 2 equipped boat that I took on for some repair work.

When I shift it into fwd or rev. the rpms come up a bit approx 400 rpm before the gears engage.

Basically the throttle is opening prior to shifting. It grinds going into reverse.

Base idle is OK and on the low side.

No stalling, but the Morse throttle control lever is stiff.

I have dealt with sticky short cables and poor adjustments in the past but have never seen anything quite like this.

Thanks for any help you can provide.

Misfit
 
Thanks BT

Is there a preferred procedure for setting the opening point for the throttle plates after gear engagement?

Thank you
Misfit
 
Usually right after the indent for fwd or rev gear. Shift control box into fwd detent, adjust shift cable to match.
Alpha`s do grind going into gear
 
Yes there is,

Has short shift cable been replaced?

If it has this cable end may need to be readjusted. So the answer this is important to the adjustment procedure.
If not then you may need a simple adjustment





1. Keys out of ignition!

2. trim outdrive all the way down then back up a count of two seconds.

3. Put throttle handle in full forward wide open throttle position.



4. go to engine and locate shift bracket with TWO cable ends attached. It may be on Valve cover.

5. Remove both cables and pay special note to which one is which!! one is control and the other is short shift cable.

6. Push short cable end in all the way while rotating prop C'clock wise and prop should lock (make sure that cable is seated as far as it will go with light pressure when prop is engaged and lock). This puts outdrive in full forward gear.

7 with light pressure pushing, measure from center of hole in short cable plastic end that you took off of the shift bracket to the adjustable trunion (brass typically but could be plastic and is on the threaded part of the cable).
If factory cable the trunion will be crimped and NON adjustable. If it has been replaced then it will be adjustable.

8. Adjust the center of the trunion to the center of the cable end hole to exactly 6 inches!

9. Once this is done, reinstall back onto shift bracket.

10. Now take control cable and adjust trunion on that so the cable fits back into bracket. DO NOT TIGHTEN ANYTHING FOR THIS CABLE YET.

11. Once you get it to line up and install into bracket pull it out and spin trunion 4 turns AWAY from cable end.

12. Now install cable back into cable brack and secure this cable it as it was before removal.

13. Now move shift control to neutral. Prop should spin freely with no clacking.

14. Now Shift control to Ten oclock (detent) ONLY. spin prop C'clockwise and prop should engage and lock up. If you are good for now.

15. Now shift to nuetral and then back to 2 oclock (detent) for reverse, NO FUTHER. Spin prop Clock wise and prop should lock.

If prop does lock easily in both directions and spins freely in neutral then you are done. IF NOT report back and we can go over how to fine adjust cable.

All remaining shifting adjustments are done to the short cable or V notch bracket where short cable is mounted once the control cable is reinstalled in step 12

Recheck your throttle issue when shifting issue and report back
 
Hi Guys

Will be getting back to all.

Short cable is likely original.

The boat sits in salt water all season.

It is a mooring lifter in Scituate Harbor Mass.

It sees little use.

Things are getting weird here in Mass.

Don’t know when I will be able to get back to the boat.

Stay safe.

Misfit
 
I know this is a old thread, but relevant to my situation. Had my Bravo 3 full service done at the end of last season. All new seals, 0-Rings, Bellows, Boots, Shift Cable, etc. Just got the chance to get out in the boat last weekend for the first time this season. Throttle adjustment seems fine. Shifting into Forward works just fine and is smooth. However, when shifting into reverse, it seems to "slam" into reverse, meaning it appears the RMPs are increasing before the Shift into reverse occurs, causing a unintended excessive reverse motion when it engages. I'm guessing the new Shift Cable needs to be adjusted. It would be a PITA to pull the boat and take it back to the service center for a simple adjustment that I might be able to do.

KGhost's post above seems to cover this adjustment. I don't think I need to mess with the Throttle Control Cable, just the Short Shift Cable. Can someone confirm that the KGhost's shift adjustment instructions are good for a Bravo 3 on a 7.4L Merc? Especially with Step 8 and Step 11, where specific measurements are given (6" and 4 Turns). Is it the same on a Bravo 3 as well as the Alpha 1 Gen 2 as the OP has? Thanks in advance!
 
That procedure is for Alpha drives. Bravo has a plastic piece which presets the shift cables.
 
Thanks kghost! So, if the shift cable on the Bravo has a preset plastic piece, is it not adjustable? Or is there still a Brass Trunnion adjustment capability? Sorry, I'm not near the boat at the moment and just don't remember the layout.
 
Typically Factory installed short shift cables the barrel/trunion is dimpled at a specific distance. Any replecement cables for any mercruiser are asjustable
 
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