Motor dosent start less given more gas

67johnson

Seaman Apprentice
Joined
Aug 19, 2005
Messages
31
Hello im new to this site and i have an old 67 johnson 60hp that I rebuilt but not as far as pistions. I had 2 great runs with the engine no trouble starting. The third time it took along time to get it runing. we finialy got it runing but it wouldnt go over like 5 miles an hour when it dose like 30 or 35. so what we did was check the timing it was ok. then we re spaced the points they seemed ok. we cleaned the spark plugs they were prety fauled probly cause the low compression. i will probly get non fauling sparks like use to be in it. spark was geting through all spark plugs that wasnt it. So we went done to the dock that night when no one was there. My dad said that was the first time the boat never left the dock. she just wouldnt run. When the key was turning u can here the engine start up and then just stall. we tryed fuel down the carb no differnts. If we helld the throtel open about half way it would run the minute u let it down she stalled. we were there trying all adjust ments to try to fix it we had to stop to let the starter cool down cause it wouldnt crank the engine we had to put jumper cables from the truck to the boat battery cause it died. we didnt want to burn the starter out so we just left no better no worse. i just took the carb off to see if the float was messed up it seemed fine i have yet to put it back on and see if there is a difference. Need help
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: Motor dosent start less given more gas

Your explanation of the problem indicates that the carburetor is fouled, gummed, clogged. The cure would be to dismantle, clean, and rebuild it completely, then adjust it as follows.<br /><br />(Carburetor Adjustments - Older V/4 Downdraft Carb)<br />(J. Reeves)<br /> <br />NOTE: The early model downdraft carburetors incorporated "Adjustable High Speed Jets". The later model downdraft carburetors used "Fixed High Speed Jets". Follow the below instructions accordingly. If you do not have adjustable high speed jets, ignore those paragraphs pertaining to same.<br /><br />Lift the center High Speed Control lever and turn it so that the point faces forward, resting on the high ridge. This will disengage the lever control gear from the individual high speed jets (slots). Have the slow speed needle valve knobs installed upside down so that they can be turned without encountering any obstruction.<br /><br />Gently seat each of the High Speed needle valves, then back each one out one (1) turn. Gently seat each of the Slow Speed needle valves, then back each one out one and one half (1-1/2) turns. NOTE... have the jam nut on the s/speed needles snug so that viberation won't have any effect on them, but loose enough so that you can turn them without a great amout of effort.<br /><br />(High Speed)<br />With a reliable person at the wheel, and one kneeling in front of the engine, start the engine (yes, it will run lousy with the above initial needle valve settings), put it into forward gear, and apply full throttle. Start with the High Speed adjustment on the left using a screwdrive that properly fits the slot.<br /><br />(High Speed Adjustments)<br />At full throttle, with the proper size screwdriver, slowly start turning one of the H/S needles in segments of 1/8 turn, waiting momentarily for the engine to respond, then repeat turning. You will reach a point where the engine will start to die out. At that point, back that needle valve out approximately 1/4 turn. Now, go to the other High Speed needle valve and repeat that procedure. At some point in that 1/4 turn out, you will find the smoothest high speed setting (you can now lower the throttle rpm). That will have both high speed needle valves set correctly, and at that point you can lift that center lever adjustment of that high ridge, keeping it lifted until the point is facing the engine, then lower it into its proper position. (When you turn that lever now, you're adjusting both High Speed needle valves at the same time.)<br /><br />(Slow Speed Adjustments)<br />Now, lowering the rpms of course, take the engine out of gear and set the throttle just to where the engine will stay running. Again, in segments of 1/8 turn, slowly start turning in one of the slow speed needle valves, waiting a few seconds between each turning for the engine to respond. As you turn the s/speed needles in, the rpms will increase..... and as it does, lower the rpms to where the engine will just stay running (otherwise the rpms will climb quite high). You will reach a point whereas the engine will either start to die out or it will spit back (sounds like a mjild backfire). At that point, back the needle valve out 1/4 turn. Repeat the process with the remaining slow speed needle. Again, at some point in that 1/4 turn out, you will find the smoothest setting. When finished, tighten the jam nut somewhat, then remove and reinstall the s/speed knobs correctly (right side up).
 

CFronzek

Petty Officer 2nd Class
Joined
Aug 11, 2002
Messages
118
Re: Motor dosent start less given more gas

You said low compression. How low?<br />One of the symptoms of low cylinder pressures is hard starting or no starting. <br />Charlie
 

67johnson

Seaman Apprentice
Joined
Aug 19, 2005
Messages
31
Re: Motor dosent start less given more gas

Ok this is the history of the boat it is a 1967 60hp v4 johnson super sea horse model # vxl-13a 2 stroke 50:1 oil ratio that my pop gave to me. Than my father and I rebuilt it.We changed the gaskets on the cylinder heads, bypasses, exhaust cover, manifold,and reed value gasket. we rebuilt the carburetor and changed the diaphragm in the fuel pump. we rewired the whole engine and put all new gas line but we didnt change the line from the tank to the engine which seemed pretty new. Also changed the spark plugs but not the points they were pretty new the timing belt was also prety new. also put new gas tanks in so they are clean. We didint go as far as pistions because it isnt worth it tho it dose smoke and the compression seems prety low.<br />when the engine is cold the compression is <br />1 95<br />3 95<br />2 90<br />4 85<br />wanted to kno how bad is that and what it should be at. <br /> We did rebuild the carb and had 2 good runs i cant see it getting fauled that fast but i am cleaning it out agan and the high speed jets are already fixed
 

Solittle

Fleet Admiral
Joined
Apr 28, 2002
Messages
7,518
Re: Motor dosent start less given more gas

Your description of the problem points to crud in the carbs.
 

67johnson

Seaman Apprentice
Joined
Aug 19, 2005
Messages
31
Re: Motor dosent start less given more gas

Well thanks for the help i cleaned the carb and im going to the dock now to see
 

67johnson

Seaman Apprentice
Joined
Aug 19, 2005
Messages
31
Re: Motor dosent start less given more gas

Well i got it runing but it would not idle at less i brought the low speed needles almost all the way closed than it dosent get enough gas to start so the carb clean out didnt do any thing and now i need to replace the starter i got 3 or 4 cranks and it heats up and wont crank it but it is like a 38 year old starter
 
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