Throttle adjustment

[gilbugs]

I finally got my boat (22ft 1986 Sea Ray Seville Mid Cabin) on the water for the first time since getting it from my brother. I had the water pump changed, the outdrive serviced and had to have the end caps replaced on the heat exchanger.

When I first put the boat under power I was nervous, because I was concerned about the power the boat would have. I ran it up to full throttle and the nose of the boat would not plane out. I was thinking that the 170 hp Mecruiser was seriously under powered for the size of the boat, but I made an adjustment on the trim tabs (aircraft term because I dont know the boating term) and the nose came down and the boat took off! Man was I relieved. She ended up toping out at about 32 mph. Now I was happy.

I need to learn more about the trim tabs because I had to make several adjustments to keep the boat level and it seemed like when I made an adjustment it always went too far like the tabs kept moving after I released the button.

Now for the real reason for this post. The throttle was a little stiff when we first launched but I could put it in gear and and power down with relative ease. The problem came when it was time to trailer the boat. This is a big boat for me, a boating novice, and I was nervous about trying to trailer the boat. Thankfully the boat ramp was unoccupied and I had all the time I needed to get the boat on the trailer.

The problem came when I would put the throttle in the neutral position. The boat would not go into neutral at the top position. If the boat was in forward and I put the throttle in neutral, the boat remained in forward. If in reverse the boat would stay in reverse. I eventually had to wiggle around on the throttle to find a position where the boat would go into neutral. However it seemed like the more I moved the throttel back and forth, the stiffer it got.

Is this a simple throttle adjustment or is there more to my probelm than it appears? If it is a throttle adjustment, how do I make the adjustment?

 

[muc]

Re: Throttle adjustment

Trim tabs is the correct name.
You just need to get used to them. Once they are close to the right position, tap the switch for one second at a time. They take a little bit of time to cause the boat to change.
Sounds like you need to check the shift interrupt system. It might be a little problem or a big problem.
If it is the problem, continued use of the boat will make it a big problem.

 

[Fishermark]

Re: Throttle adjustment

Sounds like you need to check the shift interrupt system.

Unless I missed it, you don't mention what outdrive you have. Assuming it is an Alpha, then I would agree with the shift interrupt switch. Would not be surprised if someone disconnected it because it was dying going into or out of gear.

Check to see if the switch is hooked up. If it is, with the engine running, engage the switch manually and see if the engine dies. It should.

Then it will probably be time to replace the shift cable once the shift interrupt switch is properly connected.

 

[HT32BSX115]

Re: Throttle adjustment

Unless I missed it, you don't mention what outdrive you have. Assuming it is an Alpha,

Yes.....since it's a "170 Mercruiser" (the infamous 470) it's most probably an Alpha.

If you do not have an OEM service manual, NOW would be a good time to obtain one.

It's very possible that you have throttle and/or shift cable binding (due to corrosion, wear, etc) or the cables are just maladjusted.

Regards,


Rick

 

[gilbugs]

Re: Throttle adjustment

Thanks for the replies,

The engine is a Mercruiser 470 (170 hp) with and Alpha outdrive. So there are two possibilities based on these responses.

1. The shift interrupt switch is either disconnected or malfuntioning
2. The shift cable is corroded or needs adjustment

I dont have an OEM service manual yet, but will get one right away. In the mean time, where is the shift interrupt switch located? If it is just an adjustment of the throttle cable, how do I adjusts the cable?

 

[greg82255]

Re: Throttle adjustment

Check out this link from the Adults Only section. It explains how the shift interrupt system works.

http://forums.iboats.com/showthread.php?p=1930449#post1930449

 

[gilbugs]

Re: Throttle adjustment

Thanks Greg. That was definietly helpful in understanding the system.

 

[cr2k]

Re: Throttle adjustment

This is a symptom of a bad lower shift cable. Disconnect form the converter and shift by hand. If you feel resistance it is most likely bad. The lower shift cable should slide very easy.

Another possibility is your control box. May need some lube (white grease) or may be worn.

 

[Fishermark]

Re: Throttle adjustment

This is a symptom of a bad lower shift cable.

Not really - as least not as the original poster describes it. If the lower shift cable is stiff and corroded, the symptom would be dying when trying to get out of gear - or even into gear. Not the inability to get out of gear.

Another possibility is your control box. May need some lube (white grease) or may be worn.

That is a possibility.

Be sure to let us know what you find!

 

[gilbugs]

Re: Throttle adjustment

I will let you know what the problem is when I get a chance to diasgnose it. too cold even in Texas to mess with it this weekend.

 

[gilbugs]

Re: Throttle adjustment

Wow, was it really January when I last posted this issue? Sorry for the lengthy delay in responding. The root caouse of my problem was a bad cable. I had the cable replaced and and I can easily **** in an out of neutral.