2003 150 Johnson idle issues and take off issues

[fishcrazy103]

I had these issues last year and didnt get to addressing them so now Im sure they will still haunt me this year though I have not had an oppertunity to put the boat in yet. Anywho the engine runs very well once you get it to take off on throttle up and not cut off on you. It does seem to be very cold natured when you first start it up and idles rough and you have to choke it for a good while till it warms up a bit. It then smoothes out a bit. But if I do go to a spot and stop for a while it may or may not idle smooth when I restart even it is still warm. But the main issue as I stated is the taking off problem. It wants to die when you put it into gear and as soon as you start to throttle up. I can always finally get it to take off and plane out and it runs great with no miss and very smooth then. Its just getting it to take off that is difficult. It requires that you play with the throttle a bit to make it go. If you pull back on the throttle when it tries to cut off then sometimes it will continue to idle and not cut off and I then seem to be able to goose it hard and it will then go ahead and take off. Its quite aggravating and it keeps me from putting in at the river since it could be a real problem in the current acting this way. Anyway I have seen the thread on throttle roller timing arm adjustment and wondered if this could be my problem. Is the last picture what it should look like whit the throttle in neutral with no throttle applied? Here is that link... http://www.bbcboards.net/zerothread?id=357667

I have also been told that my carbs may be out of adjustment. Any help and advice on adjusting them would be helpful. Thanks in advance for any help and advice.


Modified by fishcrazy103 at 11:14 AM 3/19/2012

[ChampioNman]

Welcome to the BBC, yes that would be correct. Your timing roller should be touching the arm. That being said, to properly align everything, disconnect the throttle cable from the linkage. Loosen the roller and push it back from the arm slightly. Move the throttle linkage forward so you can see the arm just beginning to touch the timing roller. This will set your throttle linkage in proper position. Re-install the cable on the post. Now adjust the arm so the roller touches the timing arm. This will set you close to perfect. The throttle bodies and the timing need to move in unison on the 60* motor like yours. You should also check your thermostats and make sure they are opening at ~140* with the motor running on muffs. Both heads temp need to be in that range. To better aid your cold start you should push in the shift lock out button and advance the throttle slightly, turn the key to on and depress the choke for 5 seconds then attempt to start. The motor should start with minimal use of the choke. Make sure your spark plugs are Champion QL78YC and gapped at .030".

[fishcrazy103]

I appreciate the help. I do have a Seloc manual but to say it is adequate would be a great complement to the book. I find the pictures so small and of such poor quality that with a novice knowledge as is my case it is certainly a recipe for disaster. I am thinking of getting the Johnson Service Manual. I would hope that it would be much better. Any way I do appreciate your help. Just so that I am sure that I understand your instruction correctly I am hearing that I should never see my roller not in contact with the arm at any point of travel of the throttle linkage and even before moving the arm it is still in very close proximity to or touching the arm. Is that correct? I have also read in other posts that there is a rubber or other outer part of the roller itself that can and does deteriorate and fall away over time causing the timing to be out of adjustment. Is that correct and should I be looking at the roller to see if the outer cover is gone off the roller?

I am assuming that when you say "Move the throttle linkage forward so you can see the arm just beginning to touch the timing roller." that the ARM you are referring to is the one that attaches to the top of the roller arm between the roller and the set screw? I would then make any adjustments to the throttle cable to make that reconnect without moving the linkage out of that position. Then adjust the roller to be in contact withe the arm.

I am sorry to be so ignorant about this but I dont want it to be FUBAR from misunderstanding good instructions. Thanks again for your help.

[ChampioNman]

This picture will give you a better idea of the throttle roller. In this picture it is the part that is yellowing and needs to be replaced. You can see how it touches the throttle linkage.




You need to disconnect the throttle cable and move the linkage that it was connected to so that the upper throttle linkage touches the yellow throttle roller. You then adjust the throttle cable so it fits the corrected position of the linkage. You install the cable and then you adjust the timing roller assembly so everything moves as one.

[fishcrazy103]

I really appreciate the instruction and the picture helps a lot to understand what you are saying. I appreciate you taking the time to post this. I will let you know how this works when I get the boat on the water again.