1996 Yamaha S175hp salt water series Mod# TXRU6G5 UL S/N 500427.My factory manual calls for oil pump adjustment to be all the way to the stop (touching it as I interpret) is that correct? it has about .035 to .040 gap on it now. The problem I believe stems from slow trolling bumping in in and out 1 to 2 kts (its King season here) I use ring free @ the 1% ratio on every tank. On my last trip out I lost lots of power, found 1 fouled plug. Replaced plugs with OEM spec plugs gapped IAW (In accordance with)specs, same as I took out. The big question is should I adjust the oil pump linkage as the book says to "0.OO" ? or should I leave a .02 to .05 setting. Will it still get oil fully closed? does it have a built in bleed amount? or is my publication in error?
if your going to adjust it remember its with the throttle plate fully closed. that means not on the idle screw. the fastest way is to dissconect the carb shutter link from the bottom carb to insure its fully closed. I usually shoot for about .005 to .010" between the arm and the stopper. also check your plug caps and recirc valves.
they are the nipple looking things in the block. they are not easy to access and the manual never mentions them. but they are one way check valves. test them with a syringe and some alcohol. if you can suck and blow through them they are bad and can cause plug fouling and idle issues. fouled plugs are strictly a symptom never a cause.
Ok, I found the recirc valvles I think, are they the ones on the side of each cylinder on the block which also have a dual nipple at the bottom of each carb? To test them with a syringe & alcohol, do you reccomend any particular point, ie at the base of each carb or individually? also where & what kind of hosing connects them all is it special? or automotive type? When I test them am I supposed to try& push alcohol thru them or pull air thru them? If I find a bad one how do I get it out are they pressure fitted or threaded are they easily found at yamaha shops or is an order item? Do they port directly into the lower section of the cylinder area or some where else?Thanks for your help Rodbolt you helped me in the past with my trim sensor, I now pay special attention to it after each use to flush it extra special & to lube it with wd40 every other.El Dorado
Rodbolt, I found on other earlier posts about the recirc valves from that I now know that they port into the intake port & that they are pressed in.How should I remove one without destroying it flush? I also read on how to test just try to flush some alcohol thru it!! would mixed fuel be better or will the alcohol just evaporate? also where & what kind of hosing connects them all is it special? or automotive type? I do have red capped spark plug covers, so if they're resistor type is the BR type NGK plug a resistor plug?Thanks
Well I checked all 6 recirc valves, they passed me injecting alcohol into them & before the syringe was empty I would attempt to suck it back, all I got was a vaccum so am assuming the check valve portion is working as advertised!! I adjusted the mikuni oil injection pump to about .008 I'm estimating, because .005 would go in but .010 would'nt. I'm glad the recirc valves were ok as I saw on one of your past posts that they run at the tune of $26.00 each, ouch. So in conclusion I believe my oil injecrion pump was a bit rich, I'll check the plugs after my next fishin trip, hopefully wednesday, when the King Fish tournament guys are supposed to take a day off. Please tell me if you think I need to check anything else for the fouling plug symtom, or is it likely the slow trolling, bumping in in out combined with the rich setting the oil pump had was the cause of fouling a couple of plugs? Thanks, again Rodbolt, you are an intregal part of this forum, with out your expertise, it woudld't be the same. Thanks.
Yamaha 175 S/W oil injection pump adj.
6G5 UL S/N 500427.
Linear Mode
