1989 175hp Mercury starting issue

[fishbait2]

I have a 1989 Mercury 175hp oil system removed so premix gas and oil. I sometimes when I attempt to start the motor it acts like it has Hydrolic or starter is weak. It has back fired once. I had it on the lake last trip last year and started fine. Drift fished and 6 drifts started and ran fine. The 7th time did the hydro lock thing when attempting to start. Then was fine after a few attempts to start. No backfires then. I did notice one thing the throttle lever acts a little strange as I can lift it at least 1/2 way before it seems to engage the cable. I think It is way up and starts ok but when I didn’t have it as high is maybe when I have Hydro lock and a backfire the last time last year. I just purchased the boat a little over a year ago and trying to learn it and any issues that need to be ironed out Anyone know why I am getting this Hydrolic thing sometimes?

 

[Chris1956]

Your fuel pump is run by crankcase pressure and vacuum. If the fuel pump diaghram leaks, raw fuel can get into the crankcase, possibly hydro locking it.

Of course, it could be a bad starter, bad starter cables a binding bearing, or other stuff.

 

[fishbait2]

Your fuel pump is run by crankcase pressure and vacuum. If the fuel pump diaghram leaks, raw fuel can get into the crankcase, possibly hydro locking it.

Of course, it could be a bad starter, bad starter cables a binding bearing, or other stuff.

Thanks for the reply, The last time I ran it the motor started fine and ran great in the lake. Started it 6 times drift fishing lake Erie. Motor was down and not tilted at any point on the lake. Went to start and had the hydro lock thing. Or seemed like not enough power to get the motor to turn over passed a 1/4 turn. Starter was changed out. The last starter did the same thing. The separate gas oiler is disconnected so pre mix now. The guy I purchased the boat from started it on a high t throttle. Said it was cold natured . He said it had a new starter leading me now to believe it’s something deeper.

 

[racerone]

Load test your battery.----Inspect battery cables.-----Take starter apart for inspection / ohm test on armature.----What name / part # is on the replacement starter ?-----Many Mercury starters look the same, but they are not all the same.

 

[cyclops222]

Classic fresh water corrosion of starter cables corroded UNDER the insulation.
Can be both plus and minus cables.
carry your car jumper cables with you on the boat.
Connect battery Positive cable to starter motor positive post.
Connect battery Negative to heavy , solid part of starter motor of engine block.
Does is spin fast and steady ? No ? With jumper cables still connected. Turn Ignition to the STARTER position. Spins fast and starts ? Should be the 2 big cables dying erratically.

 

[Mc Tool]

Other thing is that if it is a weak starter for whatever reason , opening the throttle also advances the spark . If you give it wot you applying full advance at cranking speed .....which wont help.
What condition are the ring gear and pinion ? If a smear of grease on the pinion teeth improves things it usually means they are worn . Are the starter shaft bushes lubed ?

 

[cyclops222]

I keep forgetting the Link And Synch of most O B. Since my motors start at idle setting with just some choke squirt by pushing in the key switch.