1988 mariner 200hp slow take off

mickab · Mar 28, 2012

hi again, few more questions about this motor. in an earlier post i had cooling issues but checked everything and it will start to pee just above idle, and the stream gets stronger with higher rpms. now a new problem. when i hammer down on it to bring the boat up on plane it boggs for a few then finally takes off. runs like a champ at WOT. but on take off it boggs bad, it doesent dieor anything. if i go back to idle it will do that just fine. im thinking carbs and spark plugs, but on a 70 hp merc 92 model on my other boat it did basiclly the same thing and it was a combination of the switch box and stator. so again any advice would be a very big help. have ordered new gasket kits and plugs, going to throw that at it tonight.

CharlieB · Mar 28, 2012

Re: 1988 mariner 200hp slow take off

As carbs get dirty the small idle passages restrict fuel and reduce acceleration long before you notice any WOT problems.

You may have some success with adding Sea Foam to your fuel, but then again, it may dislodge gunk and really plug up the idle passages.

DVA test the low speed stator winding to rule out a weak ignition, also check spark to ensure it makes a hot blue 7/16 arc cranking.

Then start cleaning carbs

mickab · Mar 29, 2012

Re: 1988 mariner 200hp slow take off

well i pulled all the carbs off and cleaned them. they didnt look to bad but i know the smallest thing could cause a big problem. when inspecting the carbs i noticed that on the front of the carbs their are two jets in the center. well the top carb was missing one and the bottom carb is missing one. what do you think about that being part of the issue?

mickab · Mar 29, 2012

Re: 1988 mariner 200hp slow take off

another thing i thought about, how about if the stator is bad? could that cause the same issue? im going to test it this weekend and ill let yall know how it goes.

CharlieB · Mar 31, 2012

Re: 1988 mariner 200hp slow take off

Have your serial # handy and check the parts pages, it will show a complete breakdown of the carbs, part # and quantity of each part

http://www.mercruiserparts.com/mercruiser_parts.asp

A weak low side of the stator can cause a weak or no spark until the engine gets up to speed and the high side then generates the voltage needed for the ignition.

Note in post #2 I recommended a spark test and DVA test the low side of the stator to rule out an ignition problem before tearing into the carbs.

mickab · Apr 1, 2012

Re: 1988 mariner 200hp slow take off

ok well had the boat out yesturday and fished it hard. other than the slow take off everything went well, even slayed the fish, lol but i used a timing light and hooked it up to the #1 spark plug wire and had my fishing partner hammer down on the throttle and i noticed the flash was very inconsistant untill it hit higher rpms. so im assuming the low side of the stator is bad, am i close or way off base? another question is whats the chances of the trigger needing to be replaced? its not much more money and ill be right their anyway. and their r three different stators for that motor so not sure which one. i was told i need to get one to handle the load of the motor as well as the electronics on the boat. my engine serial #ob263192. thanks a bunch

CharlieB · Apr 2, 2012

Re: 1988 mariner 200hp slow take off

Just remember, there is NO RETURN on electrical parts. PERIOD.

A DVA meter or DVA adaptor for any volt/ohm meter is the BEST tool for diagnosing any potential ignition problem.

A V-6 stator has TWO low sides and Two high sides, one each for each ignition switchbox. A failed low side will have a weak, or no spark on TH"REE cyls, not just #1 that you had your timing light on, AND would have very poor acceleration, if it would accelerate at all! You very well could be replacing a perfectly fine stator and STILL have your original problem.

TEST< test, and retest yet again to PROVE any electrical fault before spending any money on NON-returnable electrical parts.

mickab · Apr 3, 2012

Re: 1988 mariner 200hp slow take off

ordered the DVA adapter so i can finish up the electrical side. in post #3 i mentioned about the bowl vent jets. the book calls for all six but a friend of mine said some could be removed for the allowance of more fuel mixer to enter the crankcase for lubrication purposes. but could that also allow it to become real rich on them two cylinders? im a vehicle mechanic myself so clearly alot of simple theories do not apply to these types of engines. i would think that to much fuel would also cause a stumbling problem as well but i could be wrong. if you could give me a little more guidance on this to just cover all the bases.

mickab · May 15, 2012

Re: 1988 mariner 200hp slow take off

ok guys i know its been awhile but finally got all the parts that needed to be changed changed. as far as the manuals i have go everything electrically and mechanically check out. still have the slow take off, now to the point of wondering if my prop is to big for that motor. i have a 14 1-2 x 23p, i have no hole shot but runs about 58 mph wot only at 5100 to 5200 rpms. if im correct on this theory what would y'all recommend as far as a new prop?

CharlieB · May 15, 2012

Re: 1988 mariner 200hp slow take off

Once you are SURE that the motor is tuned to a 'T' the link and synch, ignition timing is all spot on, and the mounting height is correct for your hull, THEN weight your boat to be sure that it is near the correct weight and not carrying a lot of water-logged foam flotation.

If all that checks AND the boat motor combo has a history of running near that WOT RPM only then could it be a worthwhile bet that you have a bit too much prop and consider reducing pitch a couple of inches to get that WOT RPM closer to 5600 or even a 5800.

There are a couple of guys in the Prop forum that have access to a pretty good prop calculator, they will want to know the boat specs, length, width, weight, wetted length at speed, and a half dozen more factors and can come back with a very detailed analysis of what your boat will need.

Repost here once you get it ironed out so we can all benefit from your experience.

mickab · May 16, 2012

Re: 1988 mariner 200hp slow take off

ok i forgot to mention this and the timing makes sense. as i try to come up on plane i do notice a steady miss until it gets up and go. so i will check that really good. the boat is good as far as weight, and the boat originally had a 225 and when it ran good never had an issue. so i will check them few things. thanks again for all the help. im almost to the finish line

CharlieB · May 16, 2012

Re: 1988 mariner 200hp slow take off

mickab said:
............... as i try to come up on plane i do notice a steady miss until it gets up and go. so i will check that really good. ............................

This deserves attention, you still need to determine is it caused by a mechanical issue like a broken reed, lean idle fuel on one cyl, or an intermittant spark on one cyl at a particular throttle movement/ignition RPM or what.

Think about pulling the carbs off again so you can get to the reed blocks to see if a reed is bent or broken causing a weak idle which clears once well into the main jet.

mickab · May 17, 2012

Re: 1988 mariner 200hp slow take off

ok ill look again but when i pulled the carbs off the first time they looked fine. course i could have just over looked something. how would i be able to check each cylinder for intermittent spark? i do have a spark tester but would i be able to do it on the muffs or would it have to be in the water under a load? i have pretty much replaced all the ignition components except for the coils. is their also a dva test for the coils or an ohm check? i do have the book but its kinda vague as far as that goes. its a copy of a copied copy. lol

CharlieB · May 17, 2012

Re: 1988 mariner 200hp slow take off

If the motor is making the WOT RPM that it should then the coils and ignition are not the problem.

A leaking reed will have an effect on idle, low, and a decreasing effect thru the mid-range and have no effect noticeable on top end.

mickab · May 22, 2012

Re: 1988 mariner 200hp slow take off

ok well pulled the carbs off and didn't really notice anything wrong with the reeds that i can tell but went ahead and took it to the shop and the mechanic their said in fact the reeds were bad. he explained that the slightest little bend or wear can make a big difference. he said he found a couple bad spots in them. so i guess im replacing them. with that what do you know about the Boyesen Reeds? have talked to a few people and read alot of their reviews and they seem like a descent company with a good product but like to get many opinions before i commit.

1nebel0 · May 22, 2012

Re: 1988 mariner 200hp slow take off

First nobody talked about your air jets...not all of the cylinders will have one as you need to look at the manual...I have a 200h.p V6 older model and two cylinders don't use them.. also on my motor the each side of the carb feeds the opposite cylinder so you have to be real careful on what jet goes where.. Lastly, I alway when I buy a motor look at the idel jets if it has them and of course the high speed jets to make sure it has what it is supposed to have..Can't tell you how many times the motor would have the wrong jetting from someone messing with it...Mercury uses different size jetting in different cylinder due to the construction of the motor... Number 2 and number 5 cylinders are very prone to blowing due to lean situations...

mickab · May 22, 2012

Re: 1988 mariner 200hp slow take off

hello 1nebel0, ya i did research that and when i first got the motor it did have two air jets or "bowl vent jets as the book calls them" missing. i asked the question and was told to look in the book. and the book called for all six so i bought two and installed them. another friend of mine that's been a mercury guy for many years said they leave them out for lubrication purposes and fuel flow so i was stuck between a good or bad decision. ive wondered about that. ill have to remember which ones i put in and take them out to see what happens. as far as the rest of the jets, they are good according to the book. so hopefully those can be ruled out.

1988 mariner 200hp slow take off

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