1984 90hp muffs or no muffs what is the problem?

[bonessk01]

I have a 1984 inline 6 clyinder<br />new carb kits<br />new fuel pump kit<br />new starter solenoid<br />new fuel lines between carbs<br />new tank line and bulb <br />new tank<br />Motor will run fine in neutral whether on muffs or at the lake but just as soon as you put it into gear the motor bogs down and dies if it does stay running it bogs along at lessthan 3 mph even with inceasing throttle. If throttle is advanced to full it just stops engine.<br />Idle rpm set at 900rpm this fluctuates because of end play in throttle cable.700-1100rpm?<br />Any help would be greatly appreciated as there are no marine mechanics with in 2 hours of where I am located!

 

[Chris1956]

Re: 1984 90hp muffs or no muffs what is the problem?

Bones, It sounds like your idle mixture is set too lean to accelerate. Sometimes you can hit the choke button for a second or two when you want to accelerate, and this can help get you going. The real fix it to richen up the carbs. Assuming it idles smoothly, open the top carb idle mixture needle 1/8 turn and try to accelerate. Repeat as necessary with middle and lower carb, until it idles OK and accelerates well.

 

[bonessk01]

Re: 1984 90hp muffs or no muffs what is the problem?

Thank you I will give this a try<br />Last night I bottomed out all idle set screws, and then turned them back out to 1 full revolution.I also increased idle up to 1000rpm.But I will not be able to get it in the water until Sat.

 

[roger3645]

Re: 1984 90hp muffs or no muffs what is the problem?

Bones, check to make sure carbs are fully closed at idle and all open and close at same time. I'm with Chris in that I think your running too lean. Try the Timing and Sync of inlines posted by Clams. This procedure works great. Also try spraying some fuel mixture into each carb at idle. This should bog your motor down. If the rpm increase then that carb is being starved of fuel. Also make sure you have no leaks in your fuels lines and connections or the motor will start to suck air and not run right.

 

[JB]

Re: 1984 90hp muffs or no muffs what is the problem?

Do not take what seems like a smooth idle as evidence that all cylinders are making power, Bones. Six cylinder 2 strokes will idle smoothly on 3 cylinders.<br /><br />On the muffs, squirt some premix into each carb at idle. See what happens. Then disable each spark plug and see what happens.<br /><br />Let us know what you see the idle rpm do.<br /><br />How did the engine perform before the mass replacement/overhaul of parts?

 

[bonessk10]

Re: 1984 90hp muffs or no muffs what is the problem?

Before starting this work the motor would run and idle some what OK, but then every other time or so , out on the lake, the motor would not come up on plane and would lug along at 3-5 mph no matter how far you pushed throttle ahead. If the motor was stopped it might or might not improve.<br /> So I figured it was fuel, related started with the easiest cheapest things and have gone from there.<br />This motor was on the boat when I bought it a year ago and I was told that it had sat for a year without use so I also thought that some kits would help in the prventative maintenance.<br />Its frustrating because in my experience, I know it can run and run well, I just don't have the experience in this field to get it there!?<br /><br />I will try the spraying of the carbs tonight and see what happens <br />Thanks<br />Bill

 

[Chris1956]

Re: 1984 90hp muffs or no muffs what is the problem?

Bones, Try carb idle screws 1-1/2 turns from lightly seated. Don't be surprized if you need to open the top carb and mid carb a bit more. The bottom carb tends to run a bit richer maybe due to Gravity??

 

[bonessk10]

Re: 1984 90hp muffs or no muffs what is the problem?

well I went back and read every post i could find on inlines and started at the beginning and syncronized and timed the motor in the yard I appreciate all the coments and help and especialy the time that was taken by Clams? i think it was, to put up the proceedure for doing this work.I have yet to get the boat back to the lake because of poor weather. but it seems to be running better in the yard.<br />Thanks Bill

 

[bonessk10]

Re: 1984 90hp muffs or no muffs what is the problem?

During the syncronizing of the carbs I found that the carbs were not all set to open at the same time and none of them would have fully openned.The inital pick up timing ws off and the second pick up timing was off.I don't know why this motor even ran the way things were!<br /><br />I expect that i will still have some adjustments to make to the carb idle screws but I think you fellows have helped me to get this motor up and running THANKS!<br />Bill

 

[AMD Rules]

Re: 1984 90hp muffs or no muffs what is the problem?

Hopefully you've saved it before any damage was done. 3 to 5 mph at full throttle is not healthy. Please report back on how you make out. I'm interested to know. Good luck.

 

[bonessk10]

Re: 1984 90hp muffs or no muffs what is the problem?

I was able to get the boat out on the lake. Just got back actually!<br />The motor ran up to 4100rpm but no more however this is all it would give me last year.<br />I had a decent hole shot<br />At one point it started to die and I was able to get to the bulb and give it a squeeze and it came right back up the bulb was soft.I'm assuming I still have an air leak some where in the gas line but all in all its definitely improved over the last time I ran it.

 

[bonessk10]

Re: 1984 90hp muffs or no muffs what is the problem?

I still have to try the fuel spray in the carbs trick to see if that will improve things as well.