Newbi with a 150 johnson ?

[2ltl2lt]

swapped my powerhead on my 82 150 with a 90 model powerhead. Motor was rebuilt with about 20hrts on it when i got it from my mechanic (which I do trust) and he ran it before he bought it. everything ran good when he bought it but after the swap it now falls all over itself when getting on the throttle. once i manage to get it on plane it runs like mad but acts like it doesnt want to take gas. gas tank vent is open, fresh gas in it, fuel seperator with a new filter on it, no leaks in the fuel lines that i have found.... The only other problem i have found is that my new throttle cable is out of adjustment and is hard to get in to reverse. Not sure if that would mess with spark advance.

any help would be appreciated...... Fuel pump, timing, dirty carbs?????

 

[boobie]

Re: Newbi with a 150 johnson ?

If your unfamiliar with working on mtrs you may want to take it back to your mechanic or buy an OMC factory service manual.

 

[Dhadley]

Re: Newbi with a 150 johnson ?

Could be as simple as the carbs need attention, old fuel or a sync & link issue. Since the throttle cable doesn't do the shifting we'll assume you mean the shift cable is out of adjustment. Are you running with the thermostats out?

 

[SparkieBoat]

Re: Newbi with a 150 johnson ?

sounds like maybe fuel pump..those VRO fuel pumps sux. But do a link and sync first, check your timing, and make Sure that your cables are properly adjusted. also check your fire on each cylinder..then clean the carbs..be careful a fuel starve engine will not last long

 

[2ltl2lt]

Re: Newbi with a 150 johnson ?

I did mean the shift cable. Im a pretty mechanical person, just new to some of the quirks of boat motors and trying to learn. timing hasnt been touched since the motor was taken off of the old boat so Im gnna start by re adjusting the shift cable and cleaning the carbs.

I was told that if it is the fuel pump to put a 3-5 psi electric fuel pump inline where the prime bulb is.... Has anybody tried this and does it work??

 

[Dhadley]

Re: Newbi with a 150 johnson ?

An electric pump isn't the best idea, I wouldn't do it on a recreational carb'd motor. If you suspect a bad fuel pump you can squeeze the primer bulb as you accelerate. If that cures the problem then it is a bad pump. (By squeezing the bulb you become the pump) Do you have a single oil injection pump or the 2 old style pumps? It still sounds more like a carb or sync & link issue rather than a pump but ya never know.

Back to my origainal question - are you running thermostats or not? If not you might try running with them.

 

[2ltl2lt]

Re: Newbi with a 150 johnson ?

yeah im running thermostats and it is the single vro pump... I just started it up and did notice that the prime bulb does not seem to get hard. and after i killed the motor it was soft again. not sure if that means anything but im takin it to my mechanis this evening anyhow

 

[jonesg]

Re: Newbi with a 150 johnson ?

Bulb is supposed to get soft after the engine fires up, it becomes a flow thru device when the engine is running.
It really helps a LOT to have the factory service book, even for simple things like shift cable adjustment.
Using the model number on the powerhead, look up the service book, (not owner manual.)
www.outboardbooks.com

 

[emdsapmgr]

Re: Newbi with a 150 johnson ?

Whenever installing a new engine, you expect that the shift and throttle cables will require adjusting. You just found that out regarding the shift cable. It is possible that the throttle cable is also slightly out of adjustment. You may not be getting full throttle (full open) on the carbs. I'd pull the airbox cover off and make sure that the the throttle butterfly plates are absolutely flat (full open) when the control box handle is in the full forward position. Keep in mind that those butterfly plates can overrotate (slightly close up) if not adjusted properly.

 

[2ltl2lt]

Re: Newbi with a 150 johnson ?

ran the boat today and got it running a little better after cleaning the carbs. still doesnt want to take gas out of the hole and sounds like its struggling a bit when i get on plane, but then takes of like a rocket. Starting to lean more towards a fuel problem... Im used to truck fuel pumps either pumping or not pumping, not fuell pumps being weak..

throttle cables are adjusted correctly, has a brand new power pack on it, shift cable adjusted correctly, and runs like a bat out of the south on top end!!! hot fire on all coils and great copression on all 6... doesnt leave much other than that dang vro pump.

 

[emdsapmgr]

Re: Newbi with a 150 johnson ?

Even though the carbs were already done, you may have a fuel restriction in either the idle jets or the mids. They supply fuel when throttling up. You might want to pull those jets and have a look at them. If you are running original fuel lines, they could be a problem-they were not made to handle today's ethanol fuel. I've seen black bits of fuel hose lodge in jets, restricting them. If you haven't replaced those under the cowling, you might want to consider replacing them. Replacement Bombardier hoses of the original part number will be made/come with today's proper fuel hose material.

 

[SparkieBoat]

Re: Newbi with a 150 johnson ?

IF IT RUNS GOOD AT WOT then it is probably not your fuel pump...what is your RPMs at WOT, a prop can make a big difference in take off power, also emd mentioned checking the idle jets..i would suspect this also to be the problem. also check timing

 

[2ltl2lt]

Re: Newbi with a 150 johnson ?

5000 rpm with the 21 pitch raker and 5200 rpm wit the 19 pitch. acts the same way coming out of the hole with both props. gonna pull the carbs again soak them in carb cleaner.clean all the jets with tip cleaner and try again... all the fuel liness have been changed with alcohol resistant. gonna have mecahsnic check timing also when we take it t the water.