Pro Tuners, I need Help Please

[BigBully]

I have a 77" Johnson 200 25 inch Motor, I bought it Used about 8 years ago, It ran like a Scalded Dog when Purchased. Now comes my Mistake, I took it to a shop and had them Do a Link and SInk on it, When I went to pick it up they told me They couldent believe it ran good because it was WAY out of tune. Well, Its never ran real good since. I even took it to another Johnson Shop and they checked it and said the other shop done good. Now, On hot days when stopping for a few seconds and then throttling up it will bog out and die unless You feather the throttle. It will also Bog for about 20 feet and then It really comes to life. See it didnt do this stuff when I bought it. Then, When you throttled up It was GONE and would run right around 50mph and after they messed with it about 45 is all she will do. Can you think of anything the PO or POs Mechanic might have done Performance wise that a Reguler Mechanic would not know about? Another thing is It will Not push itself up onto the trailer, It will just Bog at Full throttle and I would think a 200HP motor should Push the truck up the ramp Anyway, I forgot to mention It got a new Powerhead 40 hours ago and didnt really make much difference in Power.<br />Thanks For reading,<br />BB...............

 

[WillyBWright]

Re: Pro Tuners, I need Help Please

Okay, I'll bite. Why did it get a new powerhead?<br /><br />Do your mechanics do their testing in the water or on a garden hose? You can't get proper carb adjustments on a hose. I think your idle mixture jets just need to be opened up 1/4 turn. That wouldn't explain the lack of top end, but it sure will cause problems with acceleration.<br /><br />Are you sure you lost speed, or could your speedometer pickup be a bit clogged? Are you getting the same full throttle RPMs as before? The tachometer would be the most reliable indicator, not the speedometer.<br /><br />It is possible that your ignition timing was advancing farhter than intended when you bought the unit. That'll give you more speed, but vastly shorten the life of your motor. That would explain a loss in top end. I know going slower isn't desirable, but neither is a hole in a piston.

 

[rodbolt]

Re: Pro Tuners, I need Help Please

also test all your fuel pumps. a weak pump wont keep the fuel bowls full at low speeds. and claen the carbs. it sounds like its running out of fuel at low speeds.<br /> good luck and keep posting

 

[BigBully]

Re: Pro Tuners, I need Help Please

Ok I said New Powerhead But mine actuly Got Rebuilt. I had one Low compression hole so We rebuilt the whole thing. At the same time He done the carbs. He also said the Fuel pumps were good. Yes they tune on a hose. He wanted to take it to the lake and do it But we never got time. I usuly Start it on the hose before Heading to the lake, (Hour Drive to the Lake) and it Idles Great But when Its in the water It Idles real low and acts like it want to die. He also told me to Move the Throttle Cam roller Just a Smidge so It gets more Timing before it starts to fuel??? (I think thats what he meant. Also can I do an Electric fuel pump on this motor?<br />Thank you for the help,<br />BB.....