wot

[Virago85]

1977 merc 175 model 1750 Boat was fine until last year arm on triger broke replaced triger set timing while i was working on it I replaced needle and seats in the carbs noticed they where leaking now my wot is only 4000 rpms floats set to specs and timing set to specs all cylinders have 150 to 155 comp any Idea's

 

[jim dozier]

Re: wot

My first thought is that you need to take a close look at how you synchronized the timing and carb throttle linkage. If nothing else changed maybe the engine isn't getting full throttle on the carbs or, more likely, isn't getting full advance on the timing. Check your link and sync.

 

[JB]

Re: wot

My first thought is that you have a dead cylinder. If that cylinder is not getting fuel it will be damaged by further running.<br /><br />Disable each spark plug in turn while at idle. A cylinder making power will cause a drop in rpm, a dead cylinder will make no difference.<br /><br />Test for a hot spark on any dead cylinders. If you have spark, try squirting a bit of premix into the carb throat for that cylinder.<br /><br />If everything checks out at idle, try squirting the premix into each carb throat while at wot, under load. If it picks up, you have identified a bad carb.<br /><br />Good luck.

 

[Virago85]

Re: wot

Well Im pretty shure its not a fuel problem Ive done this run the boat at wot pulled back to neutral and shut down vary fast pulled plugs one by one and checked they all had fuel on them I've also checked link and sink at wot all butterflys on carbs are completely open timing set to 10 degress atc on primary and 15 degress atc on secondary as the spec's call for but now that you metion it i did notice when I was seting the timeing i lost fire on the # 1 cylinder I thought the baterry was weak I let it set for about 10 minutes and it fired about 2 times then stoped the battery still turned moter over pretty good I put it on the charger then the next day tryed no fire on # 1 cranked boat up it ran for about 1 minute and then it started firing I thought all was well but I guess it could be getting hot and shutting down