johnson 150 gt

[river rat1]

hello all I hope someone can help me here my problem it has a hard time starting and when im running down the river at high speeds is cuts out like its not getting fuel I have good spark when I get ir running it idal good but when I give it gas it cuts out but if I pump the ball at high speeds it does help im thinking it not getting good gas the vro pump has been remove any help ty soo much

 

[emdsapmgr]

Re: johnson 150 gt

If priming the hose bulb helps with high speed running, likely the engine is running lean. That could be due to a weak fuel pump. You said the factory single VRO pump was removed. Does that mean that it was replaced by the old (pre 1984) pump setup, which had dual premix fuel pumps?

 

[river rat1]

Re: johnson 150 gt

yes I rebuild my 2 fuel pumps all new fuel lines to I even clean the carbs it cranks over nice but just take for ever to start or don't start I am out of option

 

[CheckmateEnticer]

Re: johnson 150 gt

Don't know about the high speed problems but as far as hard to start, have you checked the fuel primer solenoid to see if it is working? Have you tried turning the red lever on the solenoid and then squeezing the primer a few times to manually prime the intake with fuel. Mine was hard to start before repairing and starts instantly when primed manually. Mine is a 1990 Evinrude 150xp but I think they may be the same. Just a thought.

 

[emdsapmgr]

Re: johnson 150 gt

The factory does not offer rebuilt kits for those pumps. Probably is a reason the factory doesn't.. Perhaps the kits you used don't let the pumps provide the fuel it needs. Here are other things you can check: 1. the anti-siphon valve on top of the tank may be sticking, causing poor fuel delivery. 2. The ball valves in the hose can act up, exp if the hose uses is not new. For instance, make sure the hose bulb arrow is pointed in an upward direction. If it's downward pointing- the valves can act up. 3. Only use 3/8 hose line. 4. If you used any bulk fuel hose under the cowing, make sure it is not kinked. Bulk hose will kink (restriction) if it bends a tight corner. Not like factory formed hoses. 5. Make sure the plastic fuel pickup inside the tank is not loose on the hose barb at the top of the tank. 6. Probably not a problem, but just in case-take a fuel sample to check for water. 7. I doubt you are using any 5 year old grey merc fuel line. If by chance you are, switch it to some Bombardier 2013 fuel line.

 

[river rat1]

Re: johnson 150 gt

I have good fuel going to the carbs no kinks in any hose im thinking something in the fuel primer solenoid I don't totley under stand it how can I check it to make sure it working thanks and is there any way to check to see if the carbs are working my motor is 1989 johonson gt 150 the stx model

 

[emdsapmgr]

Re: johnson 150 gt

The fuel primer can be tested. Run the engine till warmed up. While running, push in on the key switch, activating the choke solenoid. When activated, the engine rpm's should drop significantly, due to an over-rich fuel condition. When the key switch is released the engine should return to normal rpm's. That's normal and indicates the fuel primer system is working.

 

[river rat1]

Re: johnson 150 gt

I fix the starting start right up now I replace fuel primer solenoid but at hig speeds it dogs out and shuts off im thinking the carbs it seems to me like it not getting gas at hugh speeds thanks

 

[emdsapmgr]

Re: johnson 150 gt

You mentioned that when at WOT, the engine would pickup rpm's if you activated the choke/primer system. That sounds like a fuel issue. However, fuel delivery problems don't always cause the engine to shut off. If you have a fuel delivery problem at WOT, the engine will usually slow down-returning to nearly idle. When the fuel pump re-fills the carbs, it will take off again. Perhaps you can clarify just what it's doing at WOT. It's unusual for it to shut down. Could be a spark issue.

 

[river rat1]

Re: johnson 150 gt

ok it idal good put it in gear its fine get up to full speed it bogs down and most of the time it shut off

 

[emdsapmgr]

Re: johnson 150 gt

Possible you have a fuel delivery problem. Do a test. Take a friend out boating next time. When running at full throttle, have the friend constantly prime the fuel hose bulb. This will force extra fuel into the carb bowls. If the engine runs normally at WOT as long as you constantly prime the fuel hose bulb, you have a fuel delivery problem. And that could be weak fuel pumps.