1988 merc engine shut off when going to reverse

[imraan47]

Hi.
I have a 1988 mercruiser alpha one gen one on a glasstream 152 tempest bowrider.
since i got it dewinterized i noticed that the engine shuts off when i put in on reverse.
well it idles fine from neutral to reverse but as soon as i push throtle further down the engine just shuts off.
any ideas what could be causing this and how can i go about fixing it.

also looking for more info on how to change spark plugs on this engine if anyone can forward me on tools that i need.
thanks iboats

 

[xltier]

Re: 1988 merc engine shut off when going to reverse

could be your interupt switch is out of adjustment.watch what it does while someone puts it in reverse.or try unplugging it to see.shouldnt try to pull it "out" of reverse unhooked thou.

 

[jtmarten]

Re: 1988 merc engine shut off when going to reverse

Classic symptom of a bad lower shift cable. Needs to be replaced along with installing the new-style shift shaft bushings/seal. The old, worn ones allow water into the shift cavity, then into the lower shift cable, which kills it.

 

[imraan47]

Re: 1988 merc engine shut off when going to reverse

Classic symptom of a bad lower shift cable. Needs to be replaced along with installing the new-style shift shaft bushings/seal. The old, worn ones allow water into the shift cavity, then into the lower shift cable, which kills it.

Hmm not good.
how much should this run me in parts?
should i do it now or just wait till the end of the season?

 

[Haut Medoc]

Re: 1988 merc engine shut off when going to reverse

I'd just replace the cable for now & do the other stuff when you change the bellows....
The cable is like fifty bucks & you will need the special cable socket (about 20 bux).....

 

[imraan47]

Re: 1988 merc engine shut off when going to reverse

I'd just replace the cable for now & do the other stuff when you change the bellows....
The cable is like fifty bucks & you will need the special cable socket (about 20 bux).....

are the how to in the manual or where can i find details on how to get do this. i will be going at it myself to save labor money.

 

[Haut Medoc]

Re: 1988 merc engine shut off when going to reverse

are the how to in the manual or where can i find details on how to get do this. i will be going at it myself to save labor money.

http://www.mercstuff.com/howdoi.htm

 

[imraan47]

Re: 1988 merc engine shut off when going to reverse

http://www.mercstuff.com/howdoi.htm

Thanks man.

Is this the right one: http://www.mercstuff.com/shiftcable1.htm

http://www.mercstuff.com/images/shiftcable.jpg

 

[Don S]

Re: 1988 merc engine shut off when going to reverse

I would be very careful following any of that mercstuff information. Lots of wrong/poor info. Like tapping with an NPT tap instead of a straight tap.
Here is a link to the OEM manual. http://www.4shared.com/document/zz_5pj9o/Service_Manual_06.html Go to section 4A for the real info on changing the cable. I would also suggest you get an OEM cable, they are much smoother in operation and MUCH better quality than the aftermarket ones an have a teflon coating on the inner cable for longer life.

 

[imraan47]

Re: 1988 merc engine shut off when going to reverse

ok bad move on my part i think.
i was told by a fellow boater that i just have to adjust the brass barrel on the shift cable at the engine.
basically that there is this lever that on this small roller and it cuts the ending of and engages it back into reverse or forward. that little roller should remain in the center and not go off. well when i moved my shifter forward it stays fine but in revers the roller moves and doesnt get back into the center so thats why my engine cuts off.

i found the picture in the manual given to me above. see page 103 (section 2A #13)
thats the roller that you can see on that lever.

basically now when i turn the engine on its roaring to 3000rpm and if i move the brass barrel the other way then if i start the engine it just wants to shoot in reverse!
so what the correct position that i should have it tune too? can it be done while boat is in the water because i cant get the boat out of the water for another month at least.
damn i should have touched anything!
please help iboats
thanks

 

[garykihara]

Re: 1988 merc engine shut off when going to reverse

k heres what you do dont panic take a deep breath and relax. unhook your cables from the side mount next to carb put your shifter in the neutral position and make sure the carb is at idle position adjust your cable until it slides onto the shaft w/o any adjustments after u slide it on shaft do the same with the shifter cable only make sure that the outdrive is in neutral u should be able to push or pull the cable back and forth in sleeve with your hand make sure you pull it all the way as far as it will go and then push it back in gently until it feels like it clicked that should be neutral then adjust that cable until it slides on shaft w no adjustments after its on there. and the problem with the reverse engine dying is your momentary kill switch mounted on the starboard side of engine

 

[imraan47]

Re: 1988 merc engine shut off when going to reverse

k heres what you do dont panic take a deep breath and relax. unhook your cables from the side mount next to carb put your shifter in the neutral position and make sure the carb is at idle position adjust your cable until it slides onto the shaft w/o any adjustments after u slide it on shaft do the same with the shifter cable only make sure that the outdrive is in neutral u should be able to push or pull the cable back and forth in sleeve with your hand make sure you pull it all the way as far as it will go and then push it back in gently until it feels like it clicked that should be neutral then adjust that cable until it slides on shaft w no adjustments after its on there. and the problem with the reverse engine dying is your momentary kill switch mounted on the starboard side of engine

woo..
this is so complex for a newbie. i need pics or something. i have the merc manual and it doesnt say anything about adjustments on there. this sucks.
as it sits now the engine revs up to around 3000rpm when i start it so i just push the level back down and it idles fine. if i put in forward it goes fine but if i go any faster and come back to neutral the rpm go down then start reving back up.

 

[jtmarten]

Re: 1988 merc engine shut off when going to reverse

Very unlikely the shift interrupt is bad.

Here's info on installing/adjusting the lower shift cable:

Installation:
http://www.amarket.com/f519.htm

Adjustment:
http://www.amarket.com/f520.htm

Make sure the distance from barrel to plastic tip is 6".

 

[imraan47]

Re: 1988 merc engine shut off when going to reverse

ok here is picture of the engine.

i read the adjustment link posted above..thank you jtmarten.
i am pretty lost still in terms of what the guidelines means by some parts.
where am i measuing the 6" from?
what end am i disconnecting the shift cable of?

 

[Don S]

Re: 1988 merc engine shut off when going to reverse

woo..
this is so complex for a newbie. i need pics or something. i have the merc manual and it doesnt say anything about adjustments on there. this sucks.

What do you mean there is nothing there on adjustment ?????? Have you looked at section 2. it's titled Removal, Installation, and Adjustments. Want to guess where you might find the instructions (with pictures) for the adjustments?

 

[imraan47]

Re: 1988 merc engine shut off when going to reverse

Don S, i assume no where to find pics and instructions is the answer

yea i looked at section 2 and read it. still pretty confusing.
also it seems like i have to have the boat out of the water cuz i need to rotate the prop by hand when doing the adjustment. boat is in the water so not sure how i can do this yet.

edit:
well the pics and stuff are in the OEM manual so it helps a little. i was thinking something like a video somewhere even if its not a merc engine probably will help.
anyhow i will attempt tomorrow and see where i get with it based on the good info on this page. thanks

 

[jtmarten]

Re: 1988 merc engine shut off when going to reverse

ok here is picture of the engine.

i read the adjustment link posted above..thank you jtmarten.
i am pretty lost still in terms of what the guidelines means by some parts.
where am i measuing the 6" from?
what end am i disconnecting the shift cable of?

The cable that has the long plastic end and the brass barrel. 6" center-center when forward gear fully engaged. Have someone turn the prop CCW while you push the cable end in to engage forward gear.

 

[imraan47]

Re: 1988 merc engine shut off when going to reverse

ok so got the issues fixed!
i don't really know what i did put just playing around. i did remove the nut and washer on the long plastic end then i measured my 6" but the cable was too short. so i just moved the barrel down abit and put it back in. its not at 6" though.
anyhow i did that and tried to put shifter in fwd and rev and the roller on that cut out switch remained center. i firied engine and it seemed ok. so i undocked and took it for a spin.
well when i go faster then come to neutral the idle is at 2000rpm. so i just adjusted the cable behind the carb there. and still didnt get it to go idle at 1000rpm like it used to. so i opened the side pannel where the shifter is and behold there was the screw really really loose there thats the same one thats coming to the back of of the carb. so i put that in place and tightned it nice.
that pretty much did it. i went to take a spin and hit top speed no problem. it was pretty wavy so i didnt really ride for long. i will test it out tomorrow after work i guess and see if i hit the same top speeds that i used to which is around 30mph.

now another problem is there is a squeeking sound i guess the fan belt. basically it makes that sound if i rev the engine at fresh start. also it will always make the sound when i trim up or down. its only when i really hold the trim up/down. so i pretty much press and release then press and release untill i get it where i want.
so what does the squeeky sound mean? replace fan belt? whats the right one for my engine?

specs: 1988 merc alpha one gen one 120hp 4cyl


thanks for all your help.
oh btw i called a repair shop and they quoted me $500!!!
i did it for $0 myself.