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J100STLCEM low RPM at WOT 1989 100hp 4 cyl.
New to forum cant wrap my head around this one:
1) starts fine, idles for the most part fine, goes up to 2,5/3k RPM's and does not go any faster. Appears that right side 1 and 3 cylinders are cooler than left side 2 and 4. Spark plugs (new) all look like they work at some point: oily/some burn residue.
2) replaced VRO2 pump, spark plugs, tried to hand pump while at WOT still 2,500 rpm not even gets on plain.
3) on the hose checked the coils with rudimentary spark tester it appears they all firing. Never try to check sparks at WOT: is there reliable testing procedure?
4) with output hose removed from the pump while hand pumping via bulge the gas spits out pretty good (therefore not a anti-syphon valve problem?). Removed and cleaned pulse limiter fitting (no results). Ran the gas line directly without pump to carbs from auxilary tank - no result therefore it is not air sucking or fuel restriction issue.
5) removed/dissasembled carbs and cleaned all orifices;
Bottom line: right side (1 and 3) is cold after running at WOT. Does not go above 2,500 rpm (in the water). On the hose RPM's rev up big time with gear and without gear.
Is this FUEL or IGNITION problem? Do i need to go and start testing Power Packs, Timer Base, Charge Coil test, Coils and such? CAN engine fire at idle all plugs and loose cylinder or two at WOT?
will appreciate any guidance before i start buying parts one after another. I am sure somebody had those symptoms before me since 1989. BTW: compression is good on all cylinders between 100 and 105 or so psi. No excessive smoke or or anything like that. Fed the engine sea foam, Stabile and things like that as well..
igor
1) starts fine, idles for the most part fine, goes up to 2,5/3k RPM's and does not go any faster. Appears that right side 1 and 3 cylinders are cooler than left side 2 and 4. Spark plugs (new) all look like they work at some point: oily/some burn residue.
2) replaced VRO2 pump, spark plugs, tried to hand pump while at WOT still 2,500 rpm not even gets on plain.
3) on the hose checked the coils with rudimentary spark tester it appears they all firing. Never try to check sparks at WOT: is there reliable testing procedure?
4) with output hose removed from the pump while hand pumping via bulge the gas spits out pretty good (therefore not a anti-syphon valve problem?). Removed and cleaned pulse limiter fitting (no results). Ran the gas line directly without pump to carbs from auxilary tank - no result therefore it is not air sucking or fuel restriction issue.
5) removed/dissasembled carbs and cleaned all orifices;
Bottom line: right side (1 and 3) is cold after running at WOT. Does not go above 2,500 rpm (in the water). On the hose RPM's rev up big time with gear and without gear.
Is this FUEL or IGNITION problem? Do i need to go and start testing Power Packs, Timer Base, Charge Coil test, Coils and such? CAN engine fire at idle all plugs and loose cylinder or two at WOT?
will appreciate any guidance before i start buying parts one after another. I am sure somebody had those symptoms before me since 1989. BTW: compression is good on all cylinders between 100 and 105 or so psi. No excessive smoke or or anything like that. Fed the engine sea foam, Stabile and things like that as well..
igor
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