1989 Mercury 150 XR4 loosing power!?!?!?

[89glasstream176]

Hi guys,

First time poster here, but have seen how helpful you guys are and wanted to seek help. I have a 1989 Glasstream with a 1989 Mercury black max 150 xr4 on it and i took it out to the lake yesterday and it started right up and took off fine at first then it seemed like it was shaking viciously and wasnt getting all the power. It would plane out and go maybe 25-30 mph. After three hours into our fishing trip, we were leaving our fishing hole and at full throttle it would not plane and maybe go 3-5 mph. The only way to crank it from that point was to trim the motor up and you could see fuel rushing out of the hood and it would fire off and then i would trim it back down and slowly putt putt off. On a side note, the primer bulb will not stiffen now. Could this be a fuel problem. The boat has set for 4 months and i put fresh gas in it. Did a compression test and it was good. I am truly dumbfounded and have no idea where to even begin. Thanks in advance and i will try to answer as many question for you guys as possible. Thanks!

 

[wired247]

Re: 1989 Mercury 150 XR4 loosing power!?!?!?

Sounds like you have a stuck float on one of the carbs. Carb rebuild time.

 

[89glasstream176]

Re: 1989 Mercury 150 XR4 loosing power!?!?!?

Could that cause all of these symptoms?

 

[racerone]

Re: 1989 Mercury 150 XR4 loosing power!?!?!?

leaking fuel indicates carburetors may need attention.----Is the oil injection system in service and delivering the correct amount of oil ?-----What are the results of a compression test?----Do you have spark on all 6 that will jump a gap of 3/8" inch or more ?

 

[89glasstream176]

Re: 1989 Mercury 150 XR4 loosing power!?!?!?

I noticed two fuel lines have cracks in them and the compression test range from 95-100 psi. How do I check the oil thing?

 

[wired247]

Re: 1989 Mercury 150 XR4 loosing power!?!?!?

Pumping the ball and building no pressure indicates the fuel is not building pressure in the line because

a. The ball is shot

and/or

b. The needle is off its seat or the seat and or needle are bad and you are pumping raw fuel into the engine. Could be one or more carbs. This would also cause your carbs to dump gas all over the place when you tilt the motor. They are overly full.

Pull the cowl off and the silencer, push the throttle all the way forward and look in the carb throats with a flashlight. Pump the
ball and I'll bet you a donut one of those carbs is squirting gas into the manifold....or...

Your fuel enriching valve is stuck open....or... your fuel pump is leaking into the engine...or...your oil pump is leaking gas into the engine ( unlikely )

 

[89glasstream176]

Re: 1989 Mercury 150 XR4 loosing power!?!?!?

If you're willing to bet a donut than you gotta be right lol but ok I will give that a shot. If this is the case then would it just a carb cleaning or rebuild and be back to running right?

 

[wired247]

Re: 1989 Mercury 150 XR4 loosing power!?!?!?

If you're willing to bet a donut than you gotta be right lol but ok I will give that a shot. If this is the case then would it just a carb cleaning or rebuild and be back to running right?

Yep... I'd check the enricher first though. Thats easy. diconnect the line going to the carbs and pump the ball and see if fuel comes out the solenoid. The line going TO the carbs, not the one going to the enricher.

 

[89glasstream176]

Re: 1989 Mercury 150 XR4 loosing power!?!?!?

Ok I will check into it and see what I can discover. I am very new to this and will prob never find any of these you are talking about but it's all a learning experience, right?