Author Topic: Marine Q-jet issue  (Read 2591 times)

Offline jimbo

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Marine Q-jet issue
« on: July 01, 2013, 08:01:05 AM »
I own a 1985 Bayliner 2450 CB with a 225AQ Volvo-Penta (305ci) I rebuilt the Q-jet with a marine kit from Cliff's and inhaled a new electronic distributer.  First time out ran well at first, however, was low on gas and put in 30 gal. 91 octane at local marina after that could not get it above 1000k rpm's without it wanting to cut out.  At home I change out fuel/seperator filter, pulled gas flaot assembly and did my best to look in tank, could not pull pickup tube so blew air down through it.  Went out again yesterday, ran up river for 20 minutes and it ran great.  Shut her down and was enjoying the river, after a little time started up and then could only get up to 2000k rpm's above that wants to cut out.  In neutral, it runs fine at higher rpm's, appears just under load.  I did replace the fuel pump(mechanical) this winter.  I was wondering if it was carb issues what would I look for? 
Thanks

Offline Cliff Ruggles

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Re: Marine Q-jet issue
« Reply #1 on: July 02, 2013, 04:40:11 AM »
Running really bad right after fill-up could be bad fuel, or you pushed some material thru the fuel system and plugged up something in the carb.  Did you check the filter in the fuel filter housing?....Cliff

Offline jimbo

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Re: Marine Q-jet issue
« Reply #2 on: July 02, 2013, 02:07:30 PM »
I did pull the filter screen in the carb, clean as a whistle.  I too am leaning to 30 gals bad gas.  I need to get my hands on a hand held camera to look inside the fuel tank to look for debris in the bottom of tank that may have sucked up on the tube.  I will blow air back down pickup tube, change filter again and put in some stable gas dry, then give it another go. 

Thanks Cilff for the reply.  Ill let you know how it goes.  Jim

Offline Cliff Ruggles

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Re: Marine Q-jet issue
« Reply #3 on: July 03, 2013, 05:29:50 AM »
My son got a really bad tank of fuel in his Roadmaster a few weeks ago.  It would BARELY accelerate to 50mph at any throttle applied.  It was running so poorly we thought it ate the distributor cap or rotor.   Next tank all is fine......Cliff

Offline LouC

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Re: Marine Q-jet issue
« Reply #4 on: November 08, 2013, 07:57:07 PM »
Check the anti siphon valve on the fuel tank...it is a spring loaded valve that keeps fuel from leaking into the bilge if the line from the gas tank to the pump leaks. I had this problem on my '88 Four Winns years ago and the engine would start and rev in neutral fine but could not plane out or accelerate the boat.

Also you can remove the fuel filter and dump the gas out into a glass container and see if you get a layer of gunk or water on the bottom. If so I'd clean out the gas tank.