prop running backwards?

[sailorden]

Hi,

Can any one help. I have been working on an old glastron v143 jetflite with a 50 HP Merc 500 & a mercontrol unit.
I finished working on the boat and turmed my attention to the mercontol unit and replaced the inginition switch and the choke switch and then re assembled the unit.

then on the engine i replaced the starter motor and the solenoid.

It started ok and the mercotrol seemed to work ok (if very stiff) and the propeller turmed fast when you pushed it forward in gear but there was less play when you pushed it the lever backward but at least the propeller changed direction.

All seemed well but when i put it in the water and pushed the control forward the prop turned anti clockwise and the boat moved backwards at speed. When you pulled the control backwards then the boat moved very slowly forwards>

the guy that had the engine before me was a not a good mechanic but i think he did have the bottom unit off the replace the impeller.
Could he have connected something wrong when he reassembled or is if me messing with the mercontrol?

or is it something quite common related to something different?

any help at this point would be good. I have the mercontol in two pieces and have just removed th lower leg to see if i can fix this issue once and for all.

Help please!

Regards
Sailorden

 

[steelespike]

Re: prop running backwards?

I'm not familiar with the Merc controls.Something could be setup wrong I think the first thing I would do is confirm the motor is running the right way.Clockwise looking down on the flywheel.Just because starter cranks the right way doesn't mean the motor runs the right way.Merc used to reverse their big motors by running them backwards.Required a hole bunch of extra stuff but under just the right conditions a 2 stroke could run backwards.
You could also unhook the cables and see if it will shift right by hand.

 

[CharlieB]

Re: prop running backwards?

One way to check is to first remove all spark plugs to ensure that the motor does NOT accidentally start.

Shift into Forward gear, manually rotate the flywheel clockwise and observe which direction the prop turns.

Repeat shifted into Reverse.

If the shifting is backwards then you may have the cable travel in the control box reversed.

We are assuming that you have a RIGHT hand prop. Clockwise for forward, correct?

A Left hand prop (Counter-clockwise) will also make it seem as tho you have a shifting problem.

Re-read your post, looks like you've described a RH prop.

 

[CharlieB]

Re: prop running backwards?

Another possibility is that you have a counter-rotating lower unit, designed to be run on a boat with twin engines.

Check the direction of cable travel at the motor, when placed in forward gear does the cable move the linkage forward or to the rear on the engine.

Forward for foward, etc.

If the cable moves correctly then you have a CCW gearcase and will need a CCW prop.

 

[wca_tim]

Re: prop running backwards?

I was thinking the last... the drive and the prop aren't the same rotation... ie wrong prop for the set-up. that seems to make more sense to me

 

[sailorden]

Re: prop running backwards?

hi

This is all good stuff. I will try it all and report back
Thanks
Sailorden

 

[cr2k]

Re: prop running backwards?

If someone has had the control box apart the cable was probably put in the wrong place. Or as stated above you have a L hand prop.

right hand prop goes forward when turned clockwise, or the top of the prop turns to the right.

in forward gear you should be able to turn the prop clockwise and ratchet on the shift dogs. Same for reverse counterclockwise.

I believe you have the unit that has a "lost" spline on the shift rod and can not be put on wrong, but I could be wrong.

 

[sailorden]

Re: prop running backwards?

Hi

I have removed the merc 500 bottom half and religned the gear selector spline on the gear shift and all is now fine from that end. I tested the mercontrol and it seemed ok so I put every thing back together.

When i started it it pops into netural, and reverse but forward is still a problem.

What is the result of switching the cables when I can get the gear lever to go forward it goes into gear and all is well.

Maybe I have broken/worn the selector cam etc in the mercontrol & i cant work out which cable goes to which side of the Mercontrol.

At the moment the cable which is connected to the 'warm up' level goes to the gear selector and the cable which is connected to the half of the mercontol with the ingintion wiring etc goes to the throttle. Is that right?

I think the mercontrol is worn out because its so hard to put all these bits back together. Should i just get a new/recon one and go from there?

any remarks that can help me?

Regards
Saillorden

 

[sailorden]

Re: prop running backwards?

Hi all

Its fixed. As some of you suggested the cables to the Mercontrol cams etc were the wrong way around.

I must have switched them when I replaced the ignition switch and the choke button!

Learning points : (1) Always mark cables when you take them off and don't trust on memory (especially when you get a bit older!).
(2) I have learned a lot about the lower unit, gearbox, drive shafts and outboards in general!

Thanks to all, for the suggestions!
A great forum!
And now its time to get into the water and enjoy the summer!
Thanks
Sailorden