Very high idle/hard to find neutral

jamesbalog · #1 05-26-2019, 12:57 PM

My boat was just in the shop for a month and a half to get my carbs rebuilt, on the bill it stated he rebuilt the 3 carbs, adjusted throttle cables and replaced fuel lines. I picked it up Friday night and went to fish Saturday morning.

As soon as I started the boat I noticed the rpms were right around 1500 in neutral, Right around 1000-1100 in gear at idle. Once in gear it was very very hard to find neutral. Needless to say the boat went back on the trailer.

I’m assuming this is a throttle cable or control cable issue. I really don’t want to take the boat back to this guy to fix his screw up since he told me originally I’d have the boat back in a week or less and it took around 6 weeks.

Anyone have a guess at what’s wrong and maybe a walkthrough on how to fix it?

Motor is a 1981 mercury 200hp

Thanks in advance

Duke01 · #2 05-27-2019, 10:59 AM

Hi James,

I am certainly no mechanic but...I have a 1980 Merc 200. I purchased a used Seloc mechanics manual when I purchased the boat/engine last year. If I did this right, there should be two links to pics I took of of the idle speed pages. There is a idle speed screw on the port side of the motor. It is in the bottom of the first attachment. Hopefully this helps.

Duke

https://imgur.com/a/8N81dNr
https://imgur.com/a/OmTyZnA

jamesbalog · #3 05-27-2019, 06:30 PM

Quote:

Originally Posted by Duke01

Hi James,

I am certainly no mechanic but...I have a 1980 Merc 200. I purchased a used Seloc mechanics manual when I purchased the boat/engine last year. If I did this right, there should be two links to pics I took of of the idle speed pages. There is a idle speed screw on the port side of the motor. It is in the bottom of the first attachment. Hopefully this helps.

Duke

https://imgur.com/a/8N81dNr
https://imgur.com/a/OmTyZnA

Thanks! I haven’t gotten a chance to mess with it yet. Hopefully tonight or tomorrow

jamesbalog · #4 05-31-2019, 08:53 AM

I backed off the throttle cables a few turns and she’s idling greats.

Thanks for the help

Duke01 · #5 06-01-2019, 02:01 PM

Excellent, glad it worked out. My 200hp 1980 Merc idles better now that the carbs are clean and with new surface gap plugs. Need to check top speed tomorrow. Last year it was low 40's which some feel is slow for this engine.

jamesbalog · #6 06-11-2019, 07:41 AM

Quote:

Originally Posted by Duke01

Excellent, glad it worked out. My 200hp 1980 Merc idles better now that the carbs are clean and with new surface gap plugs. Need to check top speed tomorrow. Last year it was low 40's which some feel is slow for this engine.

All I get is low 40s out of mine and that’s on a good day. You may do better as I have bottom paint, an aluminum prop, usually have a heavy load and I’m sure my hull is wet too.

Remember these motors are really only putting out around 175hp at the prop.

Duke01 · #7 06-16-2019, 07:26 AM

39 mph yesterday, measured via GPS. 40+ gallons of gas. One person on board. standard 3 blade alum prop. 1980 Merc 200HP.

Destroyer · #8 06-18-2019, 02:39 PM

Quote:

Originally Posted by Duke01

39 mph yesterday, measured via GPS. 40+ gallons of gas. One person on board. standard 3 blade alum prop. 1980 Merc 200HP.

Speed is relevant to a number of things. Pitch of the prop, number of blades, cupping, prop material, and a host of other things on just the prop alone. Weather, wind and sea conditions also play a huge part in your speed.
Having said that, 39 does seem a little slow. I run a 1993 200hp Merc and regularly see mid 40's.