First Post/Medium and Highspeed bogging issue

[carrera1984]

Hello all! This is my first post here on iboats. I'm excited to become part of the community. I have used online forums for other hobbies and this one seems to be mature and helpful! Here goes for my first issue but first a little background...

I have a 21 footer mid 80's bass boat with a 200HP Mariner outboard 2 stroke 6 cylinder with "B type" carbs. I rescued it in the 2005. It was used the first 2 years of its life and sat since I came along. Using my automotive knowledge I was able to get it running very well. in 2006 my friend hit a concrete block and shredded prop/lower unit shaft. Huge mess! It got fixed early last year and we got to use almost all summer until a mechanical problem arose. I was at Wolf River in Wisconsin WOT racing home to beat a thunderstorm home. I let off the gas to go through a no wake zone and got back on the throttle as I was exiting. The boat would not go above what I would call a "slight wake speed" around ~ 8mph. I check spark and fuel. New spark plugs, new fuel pump, added power tune to carbs along with other fuel line & carb cleaners. NADA! same problem. Boat starts great, idles great, no wake speed is great and then when you go above 10mph-ish the boat just boggs and im forced to go slower.

I'm kind of thinking its a clogged jet however if one jet is bad out of the 3 double carbs would I be getting this issue? Also should the proper operation of the fuel pump be spitting reasonable amounts of fuel along with the compressions of the engine or is it sopose to be a steady stream? Should I rebuild the carbs, what do ya think? Thanks in advance and sorry for the first wordy post.

-Ryan

 

[Texasmark]

Re: First Post/Medium and Highspeed bogging issue

Welcome aboard. I'm going to bump this back to the top where it has a better chance of being seen and answered properly. I don't have the answer.

Mark

 

[j_martin]

Re: First Post/Medium and Highspeed bogging issue

Might be something simple like a broken link between the throttle arm and the trigger.

Assuming basic engine compression is good as it starts well and idles well.

Start at the bottom.
1. Inspect the obvious throttle linkage parts, including advancing it and making sure the trigger rotates properly.
2. Check the stator output at the switchboxes with a DVA
3. Link n sync, just to be sure you didn't overlook something.
4. hook up a timing light to see if it drops spark when you accelerate.
5. Punt..... No come back, somebody will think of something else.

From the sounds of it, I'll bet #1 will be it. Could be junk in the way, broken spring in the throttle arm, or something like that.

hope it helps
John

 

[mke039]

Re: First Post/Medium and Highspeed bogging issue

What is a DVA...I see that all the time. I have a multimeter which I use to check volts-resistance, is that what you mean?.
I would like to know how to check stator output. Sorry about jumping in on the post here, but this is question I have had for a while.
Thanks

 

[carrera1984]

Re: First Post/Medium and Highspeed bogging issue

Thanks for the quick reply, i appreciate it. I found some time after work to drive to where my boat is and check on a few possible solutions to my problem. I tried to wrestle off the tarp but with all the snow and ice, there was no way im getting in there to do anything for a few weeks until it starts to melt! I'll keep this thread updated when I can work on the motor.

 

[Texasmark]

Re: First Post/Medium and Highspeed bogging issue

What is a DVA...I see that all the time. I have a multimeter which I use to check volts-resistance, is that what you mean?.
I would like to know how to check stator output. Sorry about jumping in on the post here, but this is question I have had for a while.
Thanks

I too saw DVA but it was in my Merc service manual and it was where you check your stators and pulse trigger packs. So a couple of weeks ago I got curious, found out what they were and why and them made one.

A Direct Voltage Adapter is a "sample and hold" circuit that takes the very thin trigger pulses and stores them into a DC voltage that can be read by a normal DCV reading DMM, DVM, multimeter or whatever you want to call it.

The DVA consists merely of a rectifying diode, a storage capacitor and a bleeder resistor.

Mark

 

[carrera1984]

Re: First Post/Medium and Highspeed bogging issue

Finally got my boat out of storage today. Tomorrow is testing by land, and then if weather goes well ill be testing on the lake under a load, which is when the issue happens. If anybody has anything else to add, it would be appreciated because if I cant find it tomorrow, Saturday I have no internet out on the lake(45 minutes away) to update you guys/trouble shoot!

-Ryan

p.s. another fellow iboater has the same issue. He may be posting.

 

[olsenk514]

Re: First Post/Medium and Highspeed bogging issue

Hey Ryan...Good Luck tomorrow!

I did find something on mine worth noting. I'm not sure if your setup is the same, but my merc is the 2+2 setup. From what I understand the top 2 cylinders are the primary means of power when idling and low speed trolling. When you push the throttle forward to a certain point, the bottom 2 cylinders kick in.

There's an accelerator pump pulling fuel from the carbs, and sending it directly to the #3 and 4 cylinders. On mine, there was a small inline filter right after the accelerator pump. It was packed full of crud...and I mean packed. I could barely get air through it.

Needless to say, I replaced it and I'm going to test it out today. I'll report back. Let me know how you make out tomorrow.

Kevin

 

[carrera1984]

Re: First Post/Medium and Highspeed bogging issue

Alright, so I going down the list, Linkage seems Okay.

On to Stator output. I used the Clymer shop manual and a multimeter(thats what it says in the book). I set the Ohm meter at RX1 scale(2000ohm) and then get exactly 1 ohm. The book says it should be less then 1 ohm. So thats borderline but probably okay. then it says connect red lead to stator lead and black to ground. I set the ohm meter to RX1,000 scale(2000k ohm) and I get 394. This value is sopose to be zero. So this is it my stator is bad!?!?!

I decided to test my rectifier because I was right there. All testing is sopose to be done at RX1,000 scale(2000k). Out of all the different testing combiniation it says to test in the book, it failed like 4 out of 8. It came in with between 270-365 on all of those tests. Is my rectifier bad too?!?!

Should I preform the rest of these tests or just go ahead and replace these?

Side notes- Carbs seem Clean, fuel system seems good.

 

[carrera1984]

Re: First Post/Medium and Highspeed bogging issue

I searched on iboats here and its like 150 for the stator and 30 for the rectifier. Do you guys think I should go for it and spend the coinage. What brand should I go with? Is it possible that Both of the parts went bad together? Thanks in advance for your help!

-Ryan