need a yamaha tech - Page 3

mokaction · 08-13-2009, 01:54 PM

David??? did you ever fix it.. and How did you fix it?? I have the same problem. Not sure if in my case it is the low pressure fuel pump relay.

Larry

KC206 · 08-13-2009, 03:31 PM

I had a similar problem, but mine was intermittent. VST would sometimes run out of fuel at low speed; ran great at crusing speed. The problem turned out to be the pressure relief valve on the return line to the low pressure pump. Some times it stuck open causing fuel to recycle through the low pressure pump and not go into the VST. The pressure relief valve can be found tie-wrapped to the low pressure pump(looks like a small check valve).The manual lists it as a check valve, but "online parts suppliers" list it as a pressure relief valve. If your problem is continous, remove it and try blowing air thru it against the arrow. If air goes thru, it's stuck open. You can replace or try cleaning and retest with air. Cleaning, soak and shake it in WD40 and or mineral spirits for 10-20 minutes to remove any build up. I cut my old one apart and found a slight build up of a white/gray substance that looked like fine beach sand. The solvents mentioned did remove the build up with soaking and agitation. This fine build up may eventually cause fouling of the injectors; if my top rpm starts falling, I'll pull the injectors, not a difficult job,and send them out for cleaning.

mokaction · 08-13-2009, 05:35 PM

Pin Fish, I did think of that, but when I put a Voltage meter on the wiring harness to the low pressure fuel pump I got no reading when my partner turn on the start switch. Tried it countless of time still not reading

Also when I bench tested the fuel pump I was able to hear the low pressure pump activated.. So, my thoughts is there is a problem with the relay.. Just wanted to see what happen to david?? did he ever fix the problem and how he solved it.

Larry

Sequoiha · 08-14-2009, 06:53 AM

Yes it is fixed,, he brought it to us,,, what we found was the ground wire in the connector to the vst fuel pump had a broken lock pin on it inside the connector,, when the connector was plugged in it would push the pin back, so no connection was made,,

mokaction · 08-15-2009, 12:26 PM

Thanks so much for the conclusion..

08-13-2009, 01:54 PM	#21
mokaction Junior Member Cigar Minnow Join Date: Aug 2009 Posts: 3	RE: need a yamaha tech David??? did you ever fix it.. and How did you fix it?? I have the same problem. Not sure if in my case it is the low pressure fuel pump relay. Larry

08-13-2009, 03:31 PM	#22
KC206 Junior Member Cigar Minnow Join Date: Jul 2009 Posts: 1	RE: need a yamaha tech I had a similar problem, but mine was intermittent. VST would sometimes run out of fuel at low speed; ran great at crusing speed. The problem turned out to be the pressure relief valve on the return line to the low pressure pump. Some times it stuck open causing fuel to recycle through the low pressure pump and not go into the VST. The pressure relief valve can be found tie-wrapped to the low pressure pump(looks like a small check valve).The manual lists it as a check valve, but "online parts suppliers" list it as a pressure relief valve. If your problem is continous, remove it and try blowing air thru it against the arrow. If air goes thru, it's stuck open. You can replace or try cleaning and retest with air. Cleaning, soak and shake it in WD40 and or mineral spirits for 10-20 minutes to remove any build up. I cut my old one apart and found a slight build up of a white/gray substance that looked like fine beach sand. The solvents mentioned did remove the build up with soaking and agitation. This fine build up may eventually cause fouling of the injectors; if my top rpm starts falling, I'll pull the injectors, not a difficult job,and send them out for cleaning.

08-13-2009, 05:35 PM	#23
mokaction Junior Member Cigar Minnow Join Date: Aug 2009 Posts: 3	RE: need a yamaha tech Pin Fish, I did think of that, but when I put a Voltage meter on the wiring harness to the low pressure fuel pump I got no reading when my partner turn on the start switch. Tried it countless of time still not reading Also when I bench tested the fuel pump I was able to hear the low pressure pump activated.. So, my thoughts is there is a problem with the relay.. Just wanted to see what happen to david?? did he ever fix the problem and how he solved it. Larry

08-14-2009, 06:53 AM	#24
Sequoiha Senior Member White Marlin Join Date: Sep 2007 Location: Pensacola Florida Posts: 2,624	RE: need a yamaha tech Yes it is fixed,, he brought it to us,,, what we found was the ground wire in the connector to the vst fuel pump had a broken lock pin on it inside the connector,, when the connector was plugged in it would push the pin back, so no connection was made,, __________________ Kenny Mann Ms Penny Fishing Team Member NRA 172499461 Minn Kota Authorized Service Center Dealer for The Super Stick www.thesuperstick.com Emerald Coast Marine LLC Allmost Anything Computers 4610 Saufley Field Rd Pensacola Fl, 32526 1-850-456-8196 1-850-455-8318 Sequoiha@cox.net Kenny_Mann-ECM@cox.net

08-15-2009, 12:26 PM	#25
mokaction Junior Member Cigar Minnow Join Date: Aug 2009 Posts: 3	RE: need a yamaha tech Thanks so much for the conclusion..

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