twin omc v-drive starboard stalls when port in reverse

[GCurrie]

When docking my Cruise-a-Home, the starboard engine stalls when idling in forward gear if I shift the port engine into reverse. This is the only time that this happens, and it is happening with consistency. Any suggestions?

 

[Don S]

Re: twin omc v-drive starboard stalls when port in reverse

Got any other information handy, like engine type, year, etc. Pictures maybe?
Never heard of an OMC v-drive.

 

[QC]

Re: twin omc v-drive starboard stalls when port in reverse

Instantaneously, like a switch? Or slightly after the port is actually in gear and working against the idling starboard (also in gear)? What happens if you have the RPM slightly up on the starboard engine when you shift the port? Will she stay running then? What RPM is the starboard idling at?

Welcome aboard, we'd love to see some pics of your boat up in the boat section ^^^^^^

Edit: Yeah Don thinking the same . . . did OMC ever sell inboard engines independent of a I/O? There is an OMC V-4

 

[GCurrie]

Re: twin omc v-drive starboard stalls when port in reverse

They are twin 225hp OMC's with a v-drive transmission. Idle was about 8-9,000rpm. It just started happening yesterday, and the only thing I noticed was that the starboard stalled every time I would shift the port into reverse when the starboard was idling in forward. It did behave almost like a switch, but I was in the middle of docking; so, I wasn't paying close attention re when and how it happened, just what was happening and getting the engine restarted. The problem with increasing the rpm on the starboard is that this is a large craft (40ft) being docked in a small space. I don't want to ram the dock or anything

The other thing was that it only happened when exiting the slip and re-entering to dock. I wasn't troubleshooting out on the water. I actually just realized the consistency of the issue after I docked the boat. Just wondering if there is something common that may be causing this. When docking, I can't afford to have this type of issue. See above, ramming speed.....

 

[QC]

Re: twin omc v-drive starboard stalls when port in reverse

Yeah, I'm not recommending that you keep the RPM up. Just wanted to know if that solved it. If so then you eliminate anything electrical to the ignition, which is unlikely anyway, and you focus in on fuel or linkage.

 

[GCurrie]

Re: twin omc v-drive starboard stalls when port in reverse

BTW, thanks for your input.

 

[GCurrie]

Re: twin omc v-drive starboard stalls when port in reverse

I think I'll have to take it out when I'm back out at the lake and try increasing the rpm on the starboard to see if that helps. If it were related to linkage, what could that be?

 

[QC]

Re: twin omc v-drive starboard stalls when port in reverse

There are neutral ignition interrupt switches on some inboard trannies, but it really goes back to the switch off scenario, and there'd have to be some messed up wiring to have the opposite engine stall.

I think it's load related because the other drive is in gear the opposite direction, that can put a lot of load on a prop and can cause a stall, but . . . it didn't always do it, so that is why I believe fuel delivery/adjustment/carb issue, which could be linkage related too. If the idle was suddenly too low and now she's also dying, that example could be linkage . . .

Edit: Could also be tune issue and this is just the first manifestation. I am breaking a cardinal diagnostic rule here and guessing at all kinds of stuff, but that's where my head is on this one.

 

[Don S]

Re: twin omc v-drive starboard stalls when port in reverse

If you are idling at 8 or 900 (I assume you didn't mean 9000) you don't want to be shifting at any more than that.
Not being able to hear the engine, I would say you need to at least think about a compression test, a full tuneup, dwell and timing check and carb adjustment just to make sure the engine is running properly.

 

[GCurrie]

Re: twin omc v-drive starboard stalls when port in reverse

Thanks again for your input. We have had issues with the carburetors and have rebuilt them. We've also had issues with the engines idling and cutting out, which is why we increased the idle rpm's from 500 to 900 or so. That resolved the stalling issue while idling, but is probably only a band-aid fix.

The engines and carburetors are 1976 vintage, and I don't have much of a history on them prior to the last 10 yrs or so. I guess I need to have someone more knowledgeable than me look at it.

Anyway, thanks again for your input.