my 2004 model 115h.p johnson will run well up to 4000rpm then surges. pumping the fuel line pump will rectify this. the engine has a new vro pump just fitted. i also connected a different fuel tank and line.
Make (of engine): souter
Model (of engine): johnson oceanpro
fitted a new vro pump
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When you replace the VRO did you replace the pulser valve?
,yes i did
lets do some troubleshooting.
lets perform a compression check, then give me the readings.
then we are going to do a quick check of your electric choke, then test the carbs.
take your time this form wont care if it takes a couple of days to complete all this troubleshooting .
comps are140on right bank and 130 on left bank looking from the back of engine.primer is working ok. carbs have new needle and seats
Do you have a fuel pressure/vacum gauge?
yes i do ,
the first step is to check vacuum, connect the combination pressure and vacuum gauge with a clear hose,before the VRO as close as you can get it. run the engine at wide open throttle watch for bubbles and observe the gauge. there should be no bubbles and if the gauge indicates more than 4 in hg of vacuum, a restriction is present.
connect the fuel pressure and vacuum combination gauge after the vro
1 psi at 600 rpms
1.5 at 2500-3000 rpms
2.5 at 4500 rpm
tell me the results
i must let you know i am a outboard mechanic myself . i have done all these tests and they are below specs but their definately is no blockage.the engine simply runs out of fuel and light pumping on the primer keeps the engine running ok but the idle also goes out abit on the bottom carbs. i think the crankcase pressure is low it even feels low but i'm wondering what could cause this.
Ive had problems outboards before and doing the same thing you are here. I loved it when the experts just through ideas at me. It finely jogged the solution out of my head.So here goesDo you have a leak down tester? That tool has help me out more than any compression gauge. vapor separator has the vro and the choke all tied to the fuel bracket. Did you tear that down to make sure float is not saturated, and the needle is good. Pumped the primer as hard as you can. Do you see any leaks around any of these components.Well good luck
no i don't have a leak down tester but i have checked the vapor seperater and fitted a new needle and seat there as well. the float is not saturated and i have pumped the primer hard with no signs of leaks
Relist: Other. the problem has not been answered just a question have i done one thing or another but no answer to what he asked me
you told me a leakdown meter had helped you before and good luck.how is that answer a help. when i answered this i did not get a reply. no opinion to the problem with this engine.
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