Throttle and Gear Shift - Proper Use

brentm77 · **Posted:** Mon Jun 29, 2015 12:52 pm

Please help me understand the proper use of the single stick throttle and gear shift on my 1987 Horizon 170.

With my setup, you pull the stick outwards (away from the side of the boat) to put the boat in neutral. The boat needs a little gas to start, so I pull it in neutral, give it some gas, and start the boat.

My first time out on the lake last week, I thought something was wrong with my boat. It was user error (I boated a lot growing up, but have forgotten a lot). The mechanic said everything was working correctly and showed me how to put the boat in neutral when starting and give it gas (I didn't know the stick popped out to do this) and the indents you go to to shift to forward or reverse (I just thought you put the stick forward in any position to shift gears, same for reverse).

1) Do I always go back to the straight up position before pushing the stick back into the side of the boat and engaging forward or reverse? Or, can I keep the RPM's running slightly above idle when doing this? It seems like the boat died easily when the stick was straight up and not pulled out in neutral.

2) Once I am in forward gear, if I return the stick to the straight up position, will this stop forward movement, or do I need to pop the stick back out into neutral to do that? Can I pop out to neutral when the stick isn't straight up (when I am in forward a bit, to keep the engine from dying)?

3) What is the proper method to go from forward to reverse; or reverse to forward. Do I need to go to the straight up position, wait, then go to the other gear?

4) What other obvious instruction do I need about shifting and neutral? I know to inspect for gas fumes and use blower for 5 mins before starting.

Thanks for helping me out with these basic questions.

LouC · **Posted:** Mon Jun 29, 2015 2:07 pm

This is a dog clutch shifted drive so you need to know a few things.
1) Pulling the control lever out, does not put the drive in neutral so much as it totally disengages the lever from the shift system, but you can only pull it out, when its in neutral. This is used for pumping the throttle and advancing the throttle forward to set the fast idle so it doesn't stall with a cold engine.
2) never shift a dog clutch drive unless the engine is at idle speed, you will wear the gears and break or bend the linkage sooner or later.
3) if it stalls in neutral you have a carb or ignition problem that needs to be fixed first before the boat is safe to operate. No revving it to keep it from stalling and jamming it in gear.
4) dog clutch drives need to be shifted briskly or they grind, not like a synchromesh transmission that you shift gently
5) when shifting from fwd to rev, always stop in neutral briefly. Never jam it from fwd to rev.
6) the engine idle speed must be low enough to allow it go into gear with out a big jolt or slam (ie, 600 rpm in gear).
7) the ESA or ignition interrupt must function to allow the idle to drop to about 400 rpm so the dog clutch will release and the drive will shift to neutral.

Unless your engine is in good enough tune to do what I just described, it will make you life on the water very stressful. Get that fixed and make sure the shift system is adjusted correctly. A boat that does not shift right is dangerous (ie reverse gear is your brakes and if it gets stuck in FWD you can hit a dock or worse).

GottWhat · **Posted:** Mon Jun 29, 2015 2:42 pm

Here is a link to the Four Winns Owners Manual (right click, save as): http://www.fourwinns.com/upload/Documen ... rtboat.pdf

brentm77 · **Posted:** Mon Jun 29, 2015 3:40 pm

LouC - thank you for the reply. You have been very helpful on this post and others. I appreciate your patience with these basic questions.

GottWhat, I appreciate the link to the manual. But I did look at it before and it doesn't contain any detailed information on how to use the throttle and gear shift. It refers the reader to the engine manual, which is not something I have found yet and suspect doesn't have this information either.

The only thing that has me scratching my head is that the shop on Saturday said they put everything through a test and it is working as intended. I would think they would have found the same idling problem that I did because the problem was obvious even after the engine was warm. It is possible it idles better on muffs than in the water? That seems like a stretch.

I think I will buy muffs and test the idling at home before trying it on the lake again.

LouC · **Posted:** Mon Jun 29, 2015 3:50 pm

Not such a stretch, there is back pressure from the water that may cause the idle to be lower in the water. OMC says:
500-600 rpm in fwd gear in the water.
IE you can tie the boat to the dock and set the idle in gear.
I usually check mine in the water with the drive centered in reverse with it on the mooring; I use my tach dwell meter and hit rev for a min to check it...

brentm77 · **Posted:** Mon Jun 29, 2015 3:55 pm

Again, thanks. Can the idle speed be adjusted by a novice like me? It doesn't seem like it would take much adjustment if the difference between running correctly and dying is putting it in the lake. It is as simple as adjusting the idle screw slightly to make it idle a little faster?

LouC · **Posted:** Mon Jun 29, 2015 5:24 pm

Yes you can, you need to use a tach dwell meter if you want it to be accurate, but you can use the dashboard tach in a pinch if its really off. I hook up the positive lead from my tach dwell meter to the negative terminal on the ignition coil and the black lead to any engine ground. You need to find which screw on the carb linkage is the screw that adjusts the idle speed.
Does this engine have the 2bbl carb or the 4 bbl carb? Mine has the 4bbl Rochester Quadrajet. If you look at the carb while someone works the throttle lever (engine off) with the handle pulled out you'll see where the screw bottoms against the linkage when the lever is in the idle position.

brentm77 · **Posted:** Mon Jun 29, 2015 10:36 pm

Great information again. I was able to find the screw by following your instructions. It was also helpful for me to watch how the cables worked. Knowing that the throttle doesn't even pull until it passes the notch where the gear cable engages will be helpful. I will invest in a tach dwell meter soon.

I don't know what carb I have. I posted a couple of photos. I am not sure how you can determine which it is.

Thanks again for your help.

LouC · **Posted:** Mon Jun 29, 2015 10:44 pm

That's a General Motors Rochester Quadrajet 4bbl carb. When set up right they are good carbs but they are more complex than some other marine carbs.
See the green lever, look on the side it says Quadrajet right there.
You can see the idle screw right there.
These were used on millions of GM cars from 1965-1981; we had one on a 350 cu in 1975 Oldsmobile Delta 88....
If it still is prone to stalling that means you may need to adjust the fuel mixture which is a bit more involved. Just try getting it so the idle is about 600 in gear in the water . If it idles smooth then it might be fine but if it won't run smooth at that speed it may need a carb cleaning, float adjustment etc.

Mercruiser engine?
That flame arrestor is not on right; the nut on that stud is supposed to be holding the flame arrestor tight to the top of the carb. I would not be happy with whatever mechanic worked on that last...sloppy work!!!

brentm77 · **Posted:** Tue Jun 30, 2015 9:28 am

Thank you for the detailed information.

In the below photo, is the pink arrow pointing to the nut that should be tight? What is the metal thing that the nut is holding on to the flame arrestor (the one with the black plastic covering going down it)?

The yellow arrow is pointing to the idle screw. Please let me know if I am wrong.

I will try getting the idle right this weekend if I can get the tach dwell meter by then. If not, I might be winging it by adjusting it slightly higher until it idles without dying. I don't think it is going to take much.

As for the sloppiness of the mechanic. When we (my dad and I) bought the boat, we were told the engine had been rebuilt. We didn't pay much for the boat, so we figured we didn't have much to lose. You are right on on the sloppiness - we already paid to have the automobile distributor replaced with a marine distributor and replaced the water pump because the engine was overheating. That wasn't a great sign for something that had supposedly just been rebuilt.

I am sure there are more surprises in store. The mechanic we have used for the new stuff seems competent, but it is odd that he wouldn't mention obvious things or take a couple of minutes to tighten the bolt. Or question me more about why the boat was not idling in the water when it was idling in his shop. The last time I picked up the boat he said "everything is working great for what you had us check out." I guess he is literal and only looks at what we ask him to look at. It may be time to try another mechanic recommended by a friend and ask him to look over the basics for any problems.

In any case, it is obvious that I need to learn a lot more about engines if I want to save a little money by doing the basic stuff. Plus, I enjoy the work and would be safer on the water knowing how things work. I am usually the type of person that can learn new things well. I finished my basement, including plumbing and electrical, by just reading books and websites. Engines are much more technical, so I will limit my work to the easier projects that come up and pay the professionals to do the hard stuff.

Thanks again.

LouC · **Posted:** Tue Jun 30, 2015 10:07 am

The best thing you can do is get a factory shop manual for your engine + drive package and read, read, read. See the problem is this: if you're younger than about 55 or so, this is stone age technology to all the younger folks who grew up with modern, electronically controlled engines. I'm in the AARP range now (LOL) but I grew up with simple engines, that had points and condenser ignitions and carbs. So to learn how to maintain anything you had to learn this stuff.
The technology in boats of this vintage, is very similar to GM automotive tech circa 1965-1975 or so. Just before electronic ignitions and cat converters came on the scene. Why, because the EPA did not stick their muddling fingers into it, yet. Now you have the magic of I/Os with cat converter exhaust, EFI and electronic ignition. I have no problem with electronic ignition, but if you buy older boats you probably will have an easier time with a carb vs EFI (because, for EFI the parts cost more and when the boat gets old, they get discontinued and you are S.O.L.). Cat converter exhaust I would not want under any circumstances. $3000 a side to replace. No thanks EPA.

Back to your questions:
yes the nut on the top of the flame arrestor should be all the way down. That flame arrestor (instead of an air cleaner) is there for safety, if the engine ever back fires through the carb, it will prevent a fire in the engine compartment. Any mechanic who would give you the boat back like that is incompetent!!!
The hoses are supposed to go to a rubber grommet in each valve cover and run up to the outside mesh of the flame arrestor. This is to allow blow-by gases from the crankcase to be sucked into the carb. No PVC valve like cars have but some newer engines may have them. The screw you labeled is the idle speed screw.

Read, Read, Read, Learn all about marine Quadrajets because that's what you got.
Find a better mechanic.
blurry pic of mine but you see it here:
https://www.dropbox.com/s/rnbgbvteib1b0 ... t.jpg?dl=0

brentm77 · **Posted:** Tue Jun 30, 2015 1:51 pm

Great information and advice. Thank you.

brentm77 · **Posted:** Wed Jul 01, 2015 9:56 am

LouC,

What should I search for for the shop manual for the engine + drive package. I believe that is Chevy 350 _ Mercruiser. But I am sure it needs to be more specific than that.

Thank you,
Brent

LouC · **Posted:** Wed Jul 01, 2015 11:23 am

Model # or year I'd guess

www.iFourWinns.com

Throttle and Gear Shift - Proper Use

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