Engine stalls when giving gas in reverse - Maxum Boat Owners Club

tpdtopcop · 08-05-2007, 02:21 PM

Hi,

Just bought a 1989 Maxum 23 ft with cuddy. It has a 5.0 ltr mercruiser engine and the lower unit is painted so I dont know what kind of outdrive it is and maybe someone can tell me.

I bought this boat off of ebay and put it in water yesterday. Let engine warm up and put it in reverse, I give it a little gas and the engine died. Restarted and put into reverse and did not give any gas it wouldnt die but as soon as I gave it a little gas it died again. This happened every single time and damn near smacked three boats in the marina trying to get out and into the launch. Boat runs perfect otherwise. Any suggestions.

Thanks

Brad

seapuppy · 08-05-2007, 02:36 PM

hey TC...welcome to the zoo..hope you will take the time to take a boating safety course...definitely worth the money....
.what color is the outdrive painted...??..black is probably a mercruiser alpha 1...gen1...
and as for the stalling..sounds like the shift interuptor...I'm taking it doesn't do it in fwd....so...since your relatively new..I'd suggest taking it to a boat shop and have them check that.......
welcome to the zoo....and good luch with the new boat!!...

tpdtopcop · 08-05-2007, 05:49 PM

Thanks for the reply,

I am new and the last boating coarse I took was when I was 16 which was 24 years ago. Yes it only stalls when in reverse "if I give it gas" and forward is fine. The outdrive is painted black and where or how can I tell if its mercruiser, alpha or gen 1. I am fairly competent around engines so how could I tell if it is the part you are referring to that is giving me the problem. I also did a general search using google and others state I could also have a bad cable?

seapuppy · 08-06-2007, 01:55 AM

well...there is an interrupt switch that momentarily cuts the engine as you shift into gear...if that switch on the engine throttle at the carb is bad..that will cause it to stall....the cable?....I don't think so....anything is possible..but I don't think that's the case.....if there is a way to disconnect the throttle cable from the carb and the shift cable...then you can operate it manually and check to see if that is the problem...make sure if it's on a trailer to have the muffs on and plenty of water going to the drive...volvo drives are usually painted white or blue...mercruiser is usually painted black...but check the numbers and call a local dealer to tell for sure....someone could have painted the drive black......

tpdtopcop · 08-06-2007, 12:59 PM

Seapuppy,

The boat will shift into reverse and not stall. It is when I give it more throttle to go a little faster in reverse that it will stall. Would this switch cause this problem or could it be a bad cable or a cable that needs to be adjusted?

seapuppy · 08-06-2007, 04:11 PM

then it probably needs to have the cable adjusted...check that route out.....

gezy · 08-08-2007, 12:32 AM

may i just add ,

the boat must be in water to load up the cable when you shift. thats how it works the switch.

i had the same thing when i put the new engine in mine

.

when out it will shift ok.

get a good marker pen to dot cable to start with.

take out split pin. turn 1/2 one way and try .if not put back to dot
and back off 1/2 try.you may have to turn more than 1/2.

is can be a pain to setup.

or get the cable of the carb get a mate to drop it into rev for you then you can try to rev it up.

if you are stuck i got the old type switch the hard to get one. :wink:

Bluemarsh · 08-09-2007, 12:37 AM

If I have this right....in the old days boats would fly out of gear and rev up. The correction for this was to re-design and sort of (cup) the teeth on one of the gears in order for them to stay engaged. This created the problem of not disengaging. To correct this....the interrupt switch which closes and momentarily grounds out the ignition as the shifter passes into neutral and the back pressure of the engine allows the gears to disengage on the way from reverse to forward and vice-versa. Once you have shifted into reverse this switch has closed and re-opened already so it may not be the reason for your problem. The pig tails for the switch wires are probably laying on top of your starboard valve cover toward the front. If you wish to bypass the switch just pull them apart and see if things change.
I had this problem in reverse and still have it a bit in forward. If you move from very low rpm. reverse aggressively to more throttle does it still stall? If this seems to help, I would check the working of the accelerator pump in the carburetor. That initial shot of fuel the engine needs at the moment of acceleration is delivered by the accelerator pump. The linkage for this pump can be adjusted. Pull your flame arrester and have someone move the throttle handle and see if fuel squirts into your carburetor.
Unless you are a good carb. Person, I would find one and have him/her check all this out.
I have found this stalling situation to be less frequent the longer I have let the engine warm up. The next time you are out running and the engine is good and warmed up stop and let it idle in neutral and then shift to reverse (just like what causes trouble back at the dock) and see if it stalls out. A warm engine can survive acceleration on a leaner mixture.
Just my two cents!

tpdtopcop · 08-11-2007, 02:34 AM

yes it does this when the engine is warm also.

Cpuhunter · 07-17-2017, 03:08 AM

Tpd, what did you find out about This? What fixed it? I have same problem...

shrew · 07-17-2017, 02:53 PM

Quote:

Originally Posted by Cpuhunter

Tpd, what did you find out about This? What fixed it? I have same problem...

This is a 10 year old thread. The OP hasn't logged on in 10 years. Seapuppy passed away about 5 years ago.

I strongly suggest you simply start a new thread.