hard start

[Newt255]

Maybe this is a no brainer to most but it is a puzzle to me. 1986 Mercury 90hp power trim runs strong, early in the spring\summer it started great, it took a little coaxing after having sat at the dock for a week at a time, but started none the less. As the summer went on it started getting harder to start, blamed it on lack of use and all of the rest of the reasons to try to get to use it more. I was finally able to get to use it for 2 weeks in a row while on vacation. I had trouble starting it most of the time, it acted as if it was flooded, fuel dripping out of the front of all 3 carbs, but usually was able to clear it and get it running. Tried all fresh fuel, new oil in the auto blend which, after reading the posts is now in the trash. The lake level is down a lot and the dock is in the same place as in the spring and I am unable to lower the motor all of the way down, in fact a friend calculated the angle of the motor, based on length of motor, water depth and all of the good stuff and it calculates out to be approximatley a 41 degree angle that the motor is at, instead of the "90 degree" that it is when in deep water. Is this possibly what the problem has been and why it's been getting worse as the summer has gone by. I didn't think of this until the boat was on the trailer and back at home. I've been able to start it fairly easy with the muffs on and will check timing and all of the good stuff once my repair manual get's here. For now I'm going to let it set for a few days and see if it still starts ok. Thanks for any thoughts on this problem. <br />Newt255

 

[The Marine Doctor]

Re: hard start

The engines are harder to start if the angle is wrong.<br /><br />You say that fuel is comming out of the carbs?<br /><br />What is your starting procedure.<br /><br />Do you choke right away?<br /><br />TMD

 

[Newt255]

Re: hard start

Howdy and thanks for the quick response.<br />I've seen fuel dripping from the front end of the carbs, right at the leading edge of the intake venturie's<br />The usual is to pump the bulb till firm with the engine down as far as it will go, in neutral with part throttle, start cranking, pushing key momentarily to choke after motor is turning, maybe pushing choke again if it doesn't at least try to fire. I've tried to start without choking and have had the same results "flooding or whatever" just not as quickly. If I can smell fuel I pull the covers off and let it set for a couple of minutes before trying again, no choke and higher to full throttle. The last few times I've noticed that the starter starts to spin slower than normal and picks up to normal speed almost like the timing is a little advanced, at least that is my hope rather than fried starter, like I said I'm waiting for the manual to come before messing with that, I'm familiar with setting timing on a lot of automobile and agriculture engines but not on marine apps.<br />Thanks Again<br />Newt255

 

[The Marine Doctor]

Re: hard start

Reread your post..you have an inline 6 90 hp. I thought you had a newer engine.<br /> <br /><br />Those engines are almost impossible to start unless they are sucked right against the boat or new.<br /><br />If you do a search you will find out a process for a Decarb. This might be what you need...it sounds like the engine is having a hard time compressing the air/fuel mixture. Ie...low on compression. Instead of being around the 150psi mark...it might be around the 125 mark.<br /><br />Try the decarb..then get back to us.<br /><br />TMD

 

[bradley1393]

Re: hard start

If you can lower the motor farther and try again...if hard start persists could possibly be bleed lines blocked or pinched or even crank seals...Lets hope it is just bad angle

 

[Newt255]

Re: hard start

Marine Doctor<br />Thanks AGAIN<br />I'm thinking things are beginning to click together here. Either I'll have to dig the lake deeper or add more dock to get to deeper water, and the auto blend that I have taken off did seem to go thru a lot of oil this summer which I would think (duh) would definately add to the carbon problem. I'll run a compression test on it in the next couple of days (tomorrow is 32nd. wedding anniversary and probably not the best time to be wrenching on the boat ) and see what they bring up. I didn't even give the posibility of carbon build-up a thought.<br /><br />bradley1393<br />I'll have to show my ignorance on 2 cycles again.<br />"bleed lines"?? <br />I'm hoping it's angle but am willing to check out anything, it doesn't cost a lot to do some look'n and probe'n if you've got a idea what your look'n and probe'n for. <br />THANKS TO BOTH OF YOU FOR THE INFO AND THOUGHTS<br />I'll let you know how I come out, but it'll be a day or 2<br />Thanks again<br />Newt255

 

[Newt255]

Re: hard start

Howdy<br />Sorry its taken me so long to get back to you, life can get crazy. Anyway I was finally able to run a compression test on the old girl, 148-160 with the higher pressure cylinder being the bottom one on the engine and it was more like a "wet compression test" as there was more oil in that cyl. than the others. The engine had set for several days without running if that has anything to do with it. I did the search for the decarb process and found it, but have not been able to pick up the stuff to do it with, I hate to say it but the time factor isn't looking real good right now and the weather forcast is calling for possible snow in the near future. I live in Michigan so its still possible to get some on the water time yet and I'm not ready to completely pack it up for the season besides there is a lot less traffic on the lake this weather. I'm still waiting for my manual to come from Mercury, I'm thinking something went wrong with the on-line order.<br />THANKS AGAIN for all your help and I'm sure I'll be back in touch with you in the future. <br />NEWT255