1989 suzuki 85dt throttle linkage

[waffles1]

What is the best way to make sure the throttle linkage is set correctly? What does it effect if it is not? All help is really appreciated. Thanks

[James R]

There is a set up procedure in the maintenance section of the Seloc manual for your motor. It is a little bit long winded but that is what you need.

[waffles1]

Thanks. What are the symptoms if it is not correct?

[James R]

The set up of the throttle linkage is of paramount importance. The motor will run very poorly if the set up is not correct. This is the base line for carb and ignition syncronization.

[waffles1]

Thanks James. I thought I had a manual but can't find it anywhere. I went ahead and ordered a new Seloc manual yesterday and will follow your advice when it arrives. I know the linkage has been moved and that may explain the lack of "get up and go" that I am experiencing. It doesn't run bad just not up to par. Thanks, again.

[nbaker]

I also have 1989 DT85 that has a loss of power. I just purchased the factory Suzuki manual. The throttle set up for our 1989 is not as bad as the older ones. But there is a throttle valve sensor mounted on the center carb that tells the CDI unit were the throttles are at. I am in the process of replacing mine ($130.00). If that sensor is not putting out the correct voltage (.45 to .55 volts at idle and 2.7 volts at full throttle)the CDI unit may think you are at part throttle when you are actually at full throttle. In testing my TVS it failed during the test. I thought I had done something wrong but I am now convinced the sensor must have been bad. Any way I plan on installing the new sensor this weekend. The new sensors are designed a little different.

[waffles1]

I thought this was an 89 model but the title says 88. I am not sure if there's a difference between the two. I will check for a sensor on the center carb. I assume it is very noticeable? It seems to me that it has lost 15-20 percent power. Is that about the same as you experienced? What's the easiest way to check it? Thanks for your input.

[nbaker]

The 88 also has it. I am not saying this is your problem but it something to check. The procedure is not hard, but you do have to make jumper leads to install into the connector. Once that is done then you apply your power to the black and red wire, ground to the solid black and the positive lead of your volt meter to the light green and red wire and the meter groud lead back the battery ground. The idle switch must be at the lowest setting and when you apply power you read the volt meter looking for the proper voltage at idle and full power. Didn't I read earlier you have a miss? Have you performed a compression test? My engine takes several minutes to get up on plane and i have a hard time getting it back on the trailer becuase of the lack of power. I am an aircraft mechanic and these outboards are a new experience so I am not the most knowledgeable outboard tech.

[waffles1]

The first thing I did was a compression check. #1 - 120 #2 - 120 and #3 - 110. The dealer came up with the same thing and said that the compression was a little low for #3 but didn't think it was much of an issue. I just put some doel fins on the back thinking that would help but it didn't make any difference. It is a new boat and I need to see where the fins are in reference to the bottom of the boat. I was told they need to be even when the motor is all the way down. Does this sound correct? I also heard that taking a can of Sea Foam to 3/4 gallon of gas and running it straight to the engine until it is all gone does wonders for cleaning the inside of the engine. Has anyone tried this? Thanks for your response.

[nbaker]

Not sure about the fins. I have some that are mounted on lower foot. I also don't know anything about sea foam. What is it?

[waffles1]

It's an engine treatment cleaner. Do a web search thay have their own website.

[gsyfishy]

Seafoam is a de-carbing agent, which means it will burn off carbon deposits in the cylinders, be careful though because I have heard of a couple of people with older engines, that lost quite a bit of compression due to the lack of carbon. I suggest adding seafoam to your gas, just as you would stabill or any other gas additive.

[nbaker]

Waffles I just installed my new Throttle sensor this weekend. I am now seeing full power intermittently. The engine is being limited by warning system some how and only turning 3000 to 3500 and jumps to 4800-5000. I have no warning lights or buzzers. So I guess I will have to check each system that causes the engine to go into limiting. After seeing you check your title I looked at mine and it is also an 88. It is possible our engines are doing about the same thing.

[waffles1]

I am still waiting for the manual to show up before I go any further. Right now I still think the throttle linkage isn't quite correct and that's my problem. I will post if I find anything out. I do not experience any jumping of rpms. My rpms just seem to stay around 4500-4800 wot. I believe they should be about another 1000 higher.

[bowhuntrrl]

I am still waiting for the manual to show up before I go any further. Right now I still think the throttle linkage isn't quite correct and that's my problem. I will post if I find anything out. I do not experience any jumping of rpms. My rpms just seem to stay around 4500-4800 wot. I believe they should be about another 1000 higher.

Sounds like too much prop pitch . Mt DT-85 had a hard time planing with the 19 pitch that was on it when I bought it. Same symptoms as yours and about 25 mph tops. Now with a 15 pitch I get 5500 rpm and 34 mph and a great hole shot !!

[waffles1]

I had a 15 pitch prop on it and had the same problems. I now have a 19 pitch on it and nothing has changed. That's why I am still leaning to an engine issue. With the boat and motor only weighing 1000 - 1200 pounds I'd think this prop and motor wouldn't have an issue but you never know. With two or three people in it it gets up and planes ok it just seems it used to run a lot better before the linkage was tampered with.Thanks for the input I appreciate your advice very much.

[waffles1]

I finally had a chance to look into this. My model doesn't have a throttle sensor on it that I can find. I did adjust the linkage a bit but that didn't really help. I ended up taking the carbs off and giving them a a good cleaning. I put them back on and adjusted everything to specs. I took the boat out and backed it in the river still on the trailer. The boat ran better but still not up to par. I tweaked the jet screws a bit more open and nothing changed. I closed them a bit and nothing changed. The manual has the jets at 1.6-2 turns open to be in spec. What I finally did was just completely screw the jets in. I started the boat and it ran but not very good. I decided to do 1/2 turn intervals per carb at a time to see what would happen. With the jets only opened 1/2 turn each the boat ran like a champ on the trailer and when I goosed the throttle it almost jumped off the trailer. The next day off to the lake I went. The boat ran great. Better then it has in years. It came out of the whole great and my top speed was 37 mph. Unfortunately, my rpm cage was on the blink so I couldn't use it as a reference.
Every once in a while it has a slight miss which I would appreciate any advice on. Thanks all for your advice and help.

Waffles1

[outbord_115]

Sounds like too much prop pitch . Mt DT-85 had a hard time planing with the 19 pitch that was on it when I bought it. Same symptoms as yours and about 25 mph tops. Now with a 15 pitch I get 5500 rpm and 34 mph and a great hole shot !!

I'm sorry to walk over this thread but I thought you might could help me I have a 16 ft skeeter with a 115 it also has a very hard time planing but unless my tach is wrong it says I'm turning 5200-5300 rpms at 51-52 mph gps. I'm not sure of the pitch. I will get the pitch tomorrow... what does this soun like to you. I wonder if the motor it to far in the water the lower unit seems really deep below the boat when trimmed all the way down. I am thinking of purshasing a jack plate could this help planing.

[waffles1]

The fins on the bottom of the motor just above the prop are supposed to even with the bottom of the boat. Check and see if this is your problem.

waffles1

[James R]

Waffles1 the 1988 to 2000 models all have a throttle position sensor. You will find it,if its there,on the Port side of #2 carb. If you dont have one then you may be compensating by the slow run needle jet adjustment. Needle jets adjusted to your setting may be providing a weak mixture at slow running which could cause overheating.The other psiibility is that you have a sensor that is not working or your carbs are running rich due to leaking float needles or incorrectly set float heights.
These carbs usually need one plus turns for the motor to idle correctly. Remember the slow running jets still provide fuel when on main jets at wider throttle settings.

[waffles1]

I looked again and found the throttle sensor. Do you think I should replace this even though my motor seems to be running better? Do you think the miss at low speeds could be to a wrong linkage or bad sensor? all help is appreciated.

Thanks,
waffles1

[waffles1]

I did not notice any less oil being used per tank of gas. Is this still a concern I should look into?

Thanks,
waffles1

[waffles1]

I'm finally getting a chance to check this out. anyone with any last suggestions?