55HP Yamaha has popping sound

[sircampsalot2]

I have a 93 model 55Hp Yamaha outboard but I dont have the manual for it so heres a few questions. First, what oil mixture should I use?50:1? Second, It idols real rough and smokes very bad when first started up..am I useing too much oil? I just got this boat and motor and when I first took it out it ran ok but about after an hour of running it got real bogged down like I had an anchor tied to it then all of the sudden it started running fine again but Idols real rough. any suggestions? think maybe the timing is off?too much oil in mixture? Also one more question... does this year motor charge the battery on the boat or do I have to charge it every time I go out to the lake? I noticed the battery is a little low when I get back in from running it and I figure either it isnt supposed to charge the battery or It needs worked on to fix whatever is not letting it charge. Thx for any suggestions and sorry the post is so long.

 

[snapperman]

Re: 55HP Yamaha has popping sound

Hi there, Yamaha recommends 100/1. depending what brand of oil you use this can be to lean. At work "Yamaha Agency" we use 50/1 with no problem. Just a quick question your motor isn't a precision injection is it. What oil are you using. Is your battery connected properly<br /><br />Food for thought<br /><br />Cheers <br />Snapperman

 

[sircampsalot2]

Re: 55HP Yamaha has popping sound

Hi snapperman, I dont know if it is precision enjected or not,I mixed my fuel/oil 50:1 yesterday and took it out fishing and had a big problem. It was very hard to get started and when it finally did it ran very rough like it was missing or something. when its in Neutral I can rev the engine and it sounds ok I guess but when I put it into gear and give it the throttle it wont push the boat but about 2mph. My bro-n-law seems to think it may be the timing but he doesnt know anymore about boat engines than I do and I'm stumped. I pulled the plugs out to see if they were fouled but they werent. I havent changed anything from last year and It ran ok in full throttle and pushed about 30mph back then. Have any Ideas of what I could chk?

 

[snapperman]

Re: 55HP Yamaha has popping sound

can you give me the model and full serial number of the motor. The precision blend injection means the motor mixes its own oil in with the fuel. The oil resovoir is normally located under the hood (cowling) of the motor and can be filled with out removing this item. What sparkplugs are u using Make and Type. Is the motor two cyclinder single carbi or three cyclinder<br /><br />lets us know

 

[sircampsalot2]

Re: 55HP Yamaha has popping sound

The only numbers it has on it are C55TLRS and 721023. It has two carbs and I dont see a reservoir for oil the spark plugs are BNK BH810, I did notice on the side of the cowling it says (Use Premix only 50:1) so I guess I used the right mixture when I took it out. It has a little gas filter on the side of the engine I noticed... does this filter seperate the gas from the oil before it sends it to the carbs? It is a clear filter and the gas in it looks pretty clean w/ no oil in it.<br /><br />P.S Apon further Investigation I notice that when it is Idoling (Here in my front yard) Gas is coming out of a hole in the top of the carbs and running down into the engine...I know this isnt right and will cause a fire but how do I make it stop? I'd Imagine it's getting too much gas to the carbs and the hole is for overflow but I'm not sure, This is probably my problem with the missing and stuff it is probably flooding the engine but how do I fix it? Thx for all your help

 

[snapperman]

Re: 55HP Yamaha has popping sound

It sound like a stuck float in the Carbi causing flooding. from here take it in and get it serviced. It'll be cheaper in the long run.<br /><br />good luck

 

[wtrojan]

Re: 55HP Yamaha has popping sound

Hello, it might be the stuck float. And yes, getting the gas over the engine is dangerous. The filter you mention is not meant for gas and oil separation (no filer is), on contrary the idea is to get the fuel with oil mix to the engine, for it’s protection – lubricating and covering internal parts to inhibit corrosion. The oil remains diluted in gas.<br /><br />You say the last year it was running fine, and now not at all. Does that mean the boat stayed several months without use? Did you have any fuel left in the tank during this time? This could be the origin of your problem, the old fuel gumming the carbs. My strong suggestion is to start with carbs cleaning or rebuild. Change the plugs with correct spares.<br /><br />BTW, running the engine in your yard, you are using the muffs, right? You must provide water flow to your engine not to ruin it.<br /><br />Getting the manual also would be a good idea.

 

[sircampsalot2]

Re: 55HP Yamaha has popping sound

Yes, It sat a long time this winter but i chaged the gas before cranking it the first time. I agree with yall that it may be a stuck float..I will have to chk it out. I am useing muffs with water running through the engine while cranking it. Thx for the replys, Mark

 

[jim dozier]

Re: 55HP Yamaha has popping sound

All of what you describe points to the need for a complete carb cleaning/rebuild. Go to the bottom of this web page and get a manual before you do anything else. Remove the carbs, dismantle them, replace the float valves and gaskets, clean the carb and parts in carb cleaner, blow them out with compressed air, set the float and idle mixture to the specs in the manual, and reassemble them with new gaskets. Don't adjust the carbs in the driveway, the engine needs to be in the water to have the proper backpressure for idle adjustments.