Stalls when shifting into FWD

Hello I'm new here, my name is Luke and my wife and I just purchased a 92 sport nautique last thursday. I was pointed here from the2001.com

We used the boat saturday and sunday flawlessly, very happy with our new purchase. Loaded the boat sunday night and headed for a different lake monday. Within the first hour of running the boat on a different lake we began to have issues with engaging FWD gear. If running in idle, REV works great, but FWD requires a quick shift in which it'll cough and sputter a bit, but usually muddle through. Just clicking it into FWD causes it to cough, sputter out and die. Then it will not restart, unless using lots of throttle with the button pulled out to allow for revving, thn a quick shift into FWD.

I have 2 theories, but having only had the boat for about a week have limited knowledge to work from.

1. I filled up monday morning at a citgo in a small town and only put 89 octane in it. I did not think this through ahead of time and maybe higher octane would be better, though that doesnt really jive with reverse working normally. We ran 2 tanks of 93 in it the 2 days before because that was what was avaiable on the water.

2. Is there some sort of ignition interupt for the transition between neutral and FWD that could be out of adjustment? I notice that the knob that gets pulled out to free rev the boat rolls to engage the transmission.

I should also add that it seems to run like a champ once muddling through this issue, the boat has 785 hours an seems to run very well, but I do not have another inboard to compare it to.

Any suggestions??? I don't feel like its a carb issue as REV works very well and when it dies after trying to go FWD you have to clear the carb before it'll restart like it flooded or something.

Heres the thread from the2001

I chimed into another thread which seemed very similar.

Thanks for helping out the new guy.thread

well I can't get to the link from work but my first thought is the cables are out of adjustment. I don't see an issue with the octane of the gas, unless there was water in it, but that should have been caught in the seperator, so unless it is old and needs replaced not too worried about it.

What is the process for verifying the shift cable beiing adjusted correctly? It definitely seems like its related to something in the shifting process.

Chris,
Since you can't open the link, here's two posts from the link that may shed some light on the problem.

dyermullet wrote: On coolhand's boat it stalls before the throttle linkage even begins to move at the carb. We had suspected an accelerator pump shot problem but it revs/responds smoothly going from neutral into reverse. Going from neutral to forward the engine stalls before any movement in the linkage. There is no lean backfire from the engine like it would have with a out of time pump shot. And every time it stalls the engines ends up being flooded because you have to hold the throttle open in order to get it to refire.   The absence of a lean backfire along with the engine being flooded leads me to think that it was cutting the ignition, and we thought maybe it had an ignition interrupter.

8122pbrainard wrote: Post the stalling when shifting to forward question over on CCfan. The resisdent trans expert Eric of Fantastic Finish Marine visits frequently. He'll have some ideas. It's now pointing to a trans problem. I'd say the reverse clutch pack is locked up due to broken clutch plates so when the trans is shifted to forward there's locked up issue. Does the prop shaft spin any in reverse when it's in neutral?

behindpropeller wrote: You might try to temporarily short out your NSS (nuetral safety switch) there are two white wires that go to it on the tranny. The NSS keeps the boat from starting in gear. Tim

Tim,
The NSS doesn't come to play here. The engine is already running. The NSS only prevents cranking when not in neutral.

Local boat guru I just talked seems to think its in carb. In the boat buying process I found MD boats on the northeastside of indy that seemed helpful and knowledgeable. I hate to pay to have someone fix a boat I just bought though?

How do these transmissions work specifically. Looking at it briefly leads me to the believe that when the knob rolls it engaged either FWD or REV. There doesnt really seem to be the noticeable clunk into get like I/O's I've dealt with.

The Marine trans is nothing more than a hydraulic pump on the front end. It supplies pressure via the FWD/NEU/REV valve spool to ether the FWD or REV clutch packs. The FWD clutch locks up the input shaft to the output shaft. The REV clutch locks up the input to a set of planetary gears reversing the input direction and then out the tail end.

The odd thing about this problem is it's fine in reverse and the reason I mentioned somethings going on in the trans. IE: if both the forward and reverse clutch packs are engauged at the same time due to snapped plates, then there's a trans lock up issue.

BTW, The "clunk" on a I/O is due to the very crude dogs used in the lower unit. They are simply fingers that mechanically engauge with each other.

79nautique wrote: well the accel pump isn't in this equation at all. I would do a test to eliminate the cable as an issue. But whiel your out floating, disconnect the cable at the carb and then shift it into gear. If it dies then the idle, timing or idle mixture screws or a combination of them are not adjusted correctly. If it doesn't die then the cable isn't adjusted correctly. Where are you running the boat, Geist, Cicero, raccoon or monroe? or do you travel a little further out of drag race land?

Well, dragrace land is where I call home, but we boat all over. Saturday and Sunday we were on lake james up in angola indiana (we have a lake house up there, we also bought the boat from dry dock up there) and monday we were on lake freeman with some friends. We also frequent raccoon and lemon lakes when we get a chance. We pretty much hunt for smooth water and a good party.

I will try these tests soon. Is there a way to run these things on a hose like I do my sterndrives?

yes simular to an automatic. You can run it in the drive with a hose but you really can't shift it into gear without screwing up the cutless bearing in the strut for the shaft. You could disconnect it at the coupling and enguage the tranny without any harm but your not duplicating the same conditions as it would be on water since there isn't a load on the tranny created from the prop turning against the water. If you want to head to Cicero afterwork next week let me know I could come over and take a look if you don't have any luck figuring it out before hand.

Well it looks like Dry Dock is stepping up. They've told me to take it over to N3Boatworks and they'll bill dry dock. So far and very happy with Dry Dock Marina in Angola, Indiana. I'm anxious to hear what the pro's have to say. We sure love this boat so far.

Lucas,
I'm glad to hear that you're being taken care of. N3 will find the problem. Don't forget to keep us informed on what they find.

I'm surprised that Eric hasn't picked up on this thread yet. Usually he's on site by now!!

also, What trans? PCM 40 or 40a?

Lucas,
It will be interesting to see if they find more issues!

Eric,
I still don't understand why it stalled in forward and not reverse! Did the gear reduction in reverse give the engine a mechanical torque advantage and in forward the low idle was just enough to kick it "over the edge" and kill the engine?

Issue is not resolved. Boat is back at N3.

PCM 40 transmisssion

N3 just bumped the idle when it was in there friday. Debatable if it resolved anything. I'll update as I know more.

Lucas,
I'm sorry to hear about the issue. Did you opt for a new carb or are they going to rebuild the old?

I'm still curious about a earlier question to Eric:

8122pbrainard wrote: Lucas, It will be interesting to see if they find more issues! Eric, I still don't understand why it stalled in forward and not reverse! Did the gear reduction in reverse give the engine a mechanical torque advantage and in forward the low idle was just enough to kick it "over the edge" and kill the engine?

Maybe he'll pick up on it and comment.