No drive to the prop

[Dadoffive]

Hello to all. New here and never owned a boat. I am Ford/GM/Chrysler service advisor so I am mechanically inclined. Anyway, I was just given a 1989 19' Glastron bowrider 3.0 Merccruiser and alpha 1 outdrive. The one issue the previous owner was telling me was last time out he was noticing a harsh engagement into forward/drive. Then a loud bang and no more drive to the prop. No strange noises from anything like somethig is broken. Any ideas?
The only other thing I noticed is it doesn't seem to want to idle worth a darn either. Engine hasn't been started in approx 9 months and has a full tank of fuel. I kinda suspecting the carb is kinda gummed up. However, I did notice, after removing the spark arrestor, the choke is wide open on cold start. Again, any ideas? Thanks, Kevin.

 

[ktbarrentine]

Re: No drive to the prop

No more drive to the prop could be one of a number of things:
1. Blown coupler between the engine and the out drive drive shaft (accompanied by smell of burnt rubber and rubber fines at the rear of the engine.
2. Broken U-joint(s) in the drive bellows.
3. Stripped upper drive gearing (I'm betting on this)....
4. Broken vertical drive shaft at the location of the O-ring groove where the vertical drive shaft enters the upper half of the outdrive (the loud bang could have been this).
5. broken/stripped/bad lower gears (less likely than the above items)
6. Stripped prop hub (not likely based on your symptoms).

The first four would be accompanied by high engine temps as you would have lost the water pump flow in the outdrive.

Those are my "ideas". What did water temp do after the big bang theory?

 

[Dadoffive]

Re: No drive to the prop

Thanks for the info. According to the previous owner everything else remained normal. How do I gain access to the driveshaft? Remove the outdrive from the transom?

 

[bspeth]

Re: No drive to the prop

Yep,check out the video in the adults only section under mercruiser information.have a look ,then separate the upper and lower and have a look there. Get yourself a manual if you haven't got one already.Good luck.

 

[thumpar]

Re: No drive to the prop

On the choke issue, you will need to pump the throttle to set the choke otherwise it will stay open.

 

[dingdongs]

Re: No drive to the prop

you could try removing the top cap off the drive and seeing if you have lube or any gears left that are in good condition. There can be some tests done by rotating prop when in gear to see if its the shaft snapped or the gears that are at fault.do not start engine with cap removed though.

 

[Dadoffive]

Re: No drive to the prop

On the choke issue, you will need to pump the throttle to set the choke otherwise it will stay open.

As far as pumping the throttle, do I just push it to full throttle and then return it to idle position?

 

[Fishermark]

Re: No drive to the prop

As far as pumping the throttle, do I just push it to full throttle and then return it to idle position?

Generally speaking, to start a carbed boat, you put the gear shift lever in throttle only position, then pump it a couple of times and leave it about 1/3 of the way open. Keep your hand on the lever and once the boat starts you can throttle it down a little. It needs a little time to warm up before it idles well typically. Be sure to check that the choke plate is actually closing.

On the other issue - I would put money on a broken drive shaft in the outdrive (#4 on kt's list).

 

[Dadoffive]

Re: No drive to the prop

Thanks for the info! I was just speaking to one of my techs and he said to put it in throttle only I have to pull the throttle arm out then push it foward. Is this correct?

 

[Fishermark]

Re: No drive to the prop

Thanks for the info! I was just speaking to one of my techs and he said to put it in throttle only I have to pull the throttle arm out then push it foward. Is this correct?

There are several different styles. Some have a button you push in while engaging the throttle, others are as you describe.

 

[Dadoffive]

Re: No drive to the prop

Would said button be located at the bottom/center of the throttle arm?

 

[garbageguy]

Re: No drive to the prop

Would said button be located at the bottom/center of the throttle arm?

yes, at the pivot point

 

[Dadoffive]

Re: No drive to the prop

Ok, I guess I made a mistake! As far as the prop not spinning I was incorrect. It does spin some as I rev up the engine to approx 3k rpm the prop is probably doing 45-50 rpms. Any other ideas?

As far as getting this thing to idle smoothly is just not seem to want to cooperate. It surges, then sputters, the surges and then stalls all while the throttle is in a steady position. It seems to have a bit of a miss when its trying to idle. I havent gotten a chance to pull the plugs, cap or rotor yet for inspection. I'm suspecting the carb may need to be overhauled!?! Any ideas?

 

[thumpar]

Re: No drive to the prop

Have you checked to see if the lower is engaging in gear? If it is then maybe a coupler. Time to investigate.

 

[Dadoffive]

Re: No drive to the prop

Have you checked to see if the lower is engaging in gear? If it is then maybe a coupler. Time to investigate.

I assume you mean all the way into gear and that its only partially engaging? That would explain the slow speed of the prop I believe. As far as the coupler, I thought when they broke that was it as far as any drive? How would I inspect for it not going into all the way into gear and how would I inspect the coupler?

 

[Bt Doctur]

Re: No drive to the prop

3K on a hose most likely burned up the impeller ,Have you checked the oil level in the drive?

 

[thumpar]

Re: No drive to the prop

See if the drive is locking both ways (it shifts in the lower). What I meant was that if the coupler went and it is in drive there may be enough friction to slowly turn the prop. Pull the drive. Put it in forward. Remove the six nuts at the bellhousing and one of the nuts to pull the pin from the trim rams. The drive is going to have to come off to figure it out at some point. At this point you don't even know if your impeller is turning so stop running it.

 

[Dadoffive]

Re: No drive to the prop

3K on a hose most likely burned up the impeller ,Have you checked the oil level in the drive?

The prop was only spinning about 40-50 rpms for a couple of seconds so I doubt it was hurt, at least I hope not!?!

 

[Dadoffive]

Re: No drive to the prop

See if the drive is locking both ways (it shifts in the lower). What I meant was that if the coupler went and it is in drive there may be enough friction to slowly turn the prop. Pull the drive. Put it in forward. Remove the six nuts at the bellhousing and one of the nuts to pull the pin from the trim rams. The drive is going to have to come off to figure it out at some point. At this point you don't even know if your impeller is turning so stop running it.

Understood! Hopefully get a chance this upcoming weekend!?! I'll post more then. Thanks for the help!

 

[Maclin]

Re: No drive to the prop

The raw water intake impeller turns all the time unless the internal shaft is broken. The drive goes into neutral but the u-joints and impeller are spinning all the time. If you ran it at all without water going to the intake grates then the impeller is hurt. Also revving to 3k in neutral will outpace the water supply to the intake grates and probably hurt the impeller also.