1986 DT 200 trouble

[Beantown]

Hi, hoping someone might be able to help me out, bought a 1989 Champion bass boat, that had been repowered with this 1986 DT200 motor three years ago, had been sitting for three years, I have been restoring the bass boat it came with and have in the process, completely removed the plastic fuel cell, and washed it out with K100, replaced all of the fuel lines and vent hoses and fill fittings, rebuilt both fuel pumps, and all three carburetors, by a professional, first run with new 93 octane, no additives, the boat fires right up, and idles fine, as you engage the motor, boat runs fine up to about 1500 rpms, and then the motor will stall, or sputter out, and I can play with the throttle, slowly, and sometimes, it will take off, like nothing and run fine, until i shut it off again. It will stall out 100 times more than it will take off and run fine, it sort of sputters through that 1300 - 2000 rpm range and then, will smooth out and run great and with plenty of power. This is a real nice freshwater motor, parts and mechanics that will look at this thing are hard to find, I have the manual and have most of the tools, have owned boats and maintained and worked on other brands of motors, boat is equipped with the smart gauge, and first run the alarm was also going off. noticed the smart gauge wasn't reading at all, so got home, found a power wire off the gray from the ignition, went out to the lake again, no alarms now, gauge powers up, correctly, and stays green, but the motor still sputters out, 90% of the time i put in in gear. should I start testing coils or CDI unit? Stator? not sure where to turn next, any help would be greatly appreciated

[booter]

Have you checked your spark plugs to see if they fouled by chance? I could be wrong, but it sounds like your plugs our fouling and once the engine gets warm enough, it will burn the crud off and run fine. Plus is your motor oil injected or are you required to premix the fuel? Just asking, I had a '99 DT200 that was oil injected.

Another thing to check is to make sure you that you don't have a kink in your fuel line somewhere like when the hose runs through the rigging tube on your boat. Lastly, I'd try squeezing the primer bulb each time before starting in case you have fuel evaporating in between runs after shutting down the motor off when it's still hot. Just a few thoughts.

[Beantown]

Thanks for your help booster, I will double check tomorrow for a kinked fuel line, although I have replaced all of them on both tanks, and I have checked my spark plugs and actually replaced them twice this spring just in case, and yes, I have an oil pump system I have checked the oil pump and filter, I have changed the fuel filter twice, and the fuel and water separator twice, I am very frustrated with this motor, I have been trying to fix it for two years. Thanks for your help.

[billnorman1]

Be careful. Even if the carburetors were professionally rebuilt everybody makes mesteeks. If a 2 stroke runs lean it will be damaged. Some of the problem sounds like a lean issue, maybe not. Change to a portable fuel tank, and double check the carburetors for trash, a low float setting or a clogged main jet.

[Beantown]

Thanks for the help billnorman1, I will keep investigating, until I figure this thing out!

[Beantown]

Hi all, just an update, I removed the spark plugs, and they were pretty wet, and fouled, and I found they were not gaped properly, they were to tight, the manual gives a range of .035 to .039, so I replaced them with new plugs and set them at .035, went for a test run, and it seemed to run a little better, it started right up, only stalled a couple of times, then it took right off, and ran great, it still stalled out a few times, but much less. so when I got home, I pulled the plugs, they were still looking wet and some carbon build up, so I cleaned them up, and increased the gap to .039, now I am on my way out for another test run. I will report back later, thanks for your help everyone.

[booter]

Good to hear that you are getting close. I'd maybe consider running some Sea Foam through you engine to help remove some of the carbon buildup.

[Beantown]

first of all, thank you very much for everyone's help here, what a great resource this is. Thanks booter, I will definitely run the sea foam tomorrow. Okay, so this morning, I actually gapped the plugs at .040, instead of .039, thinking bigger spark, because I knew it was running rich, the manual says max gap at .039 in. anyway, went to the lake, it started up a little cold blooded, and a little white smoke, and I could smell the fuel, I only choked a little, so after it idles for a few and seemed warmed up, I started out with steady throttle, then I get on it, and it runs awesome, was up to 50mph, in seconds, it was really moving, at one time playing with the wind, trim and hydraulic jack plate, the boat was up to 56 on the gps, my dash speedo isnt working, but the boat ran the best around 53mph, not full throttle, but close, but the reason I backed off because now I notice at full throttle, I'm doing 6000, rpms. This is the first time since I have had the boat, that the tachometer has worked, so I backed off for the rest of the test run, tried to keep it around 5000 rpms, and shut it off, and started it several time, and made several 1/2 mile to 1 mile runs. The motor still has a hesitation, at 1300 rpms, but this boat is running night and day better. and the boat feels dependable now, where I did not have very much confidence in this motor, before today, and obviously now, I think I need some prop help, the prop I am running on this motor, came with it, and was already, banged up a bit, needs to be reworked, and its a 3 x 14 1/2, x 20. the manual, shows a range of 18-up to a 28 pitch, ( all 14 1/2", 3 blade), should I start at 24p? My second question is, that I bought a brand new Suzuki prop, but the prop is a 14 1/4 inch prop. can I use it ? it seems to fit, same spline. Will it hurt anything? I cant return it, so.... Is there any sense in fixing the original prop, because it doesn't seem to be the right prop for my set up anyway,
what do you guys think? thanks again in advance,

[Ronnie]

If you have a factory manual it shows the circuits for idle,mid range and wot.Yours should have a limiter and the older ones kicked in about 6100-6200.I have a 1988 115 suzuki. I have a omc 24'' raker on allison-xtb and can still hit the limiter @ about 6200 so you need to go alot bigger.Omc props will fit. mines 13 spline.If you can bump the choke real quick when it bogs to see if its lean.

[billnorman1]

.040" is the proper plug gap. I'm not sure what range of prop that motor should have on a bass boat. Is that a 6 or 12 plug motor?

[Beantown]

yes billnorman1, this is a V6, the plug gap in my manual gives a range of .035 to .039, anyway, I sent out the 20p prop, and tried to use the 18p prop while my prop was getting fixed, it would not even move the boat, got the 20p prop back, it is still running mostly the same, the engine is turning 6100 rpms, at wot, 53 mph this is fully loaded, probably around 200 lbs of gear, 20 gallons of fuel, just me 250lbs, I have read that each pitch changes the rpms, approx. 200 rpms, my manual reads that the motor max rpm range, should be 5600 rpms, how much change of pitch should I shoot for ? should I go with a 22p ? thanks everyone, my engine is still starting, cold, and hesitates, and sometimes stalls out a couple of times before it will run above 1300 rpms, when I feather the throttle, it will usually smooth out and run, I am still working on this, I'm going to keep investigating, thanks to all for the help

[Beantown]

Hello everyone,
I have finally figured out my problem on this motor, it was the throttle valve switch. I read about it in my service manual, and did an electrical test on page 57 and the unit failed. I was able to find a replacement on ebay, and now my engine is running perfect. just wanted to thank everyone and also share my experience in case anyone has a similar issue.

[Tim Kelly]

Fantastic news! Very satisfying when you finally track the problem down.

[booter]

Awesome! Great to hear that your motor is running again without issues!

[billnorman1]

I don't even know what a throttle valve switch is, but I'm glad you found a bad one.

[Alumicraft145]

Nice thread. A 89 champ with an 86 suzuki is quite the set up!! I would use eth free gas!! Plus seafoam!

[Beantown]

IMG_0243[1].JPGIMG_0301[1].JPGIMG_0044[1].JPG
here is the part that I replaced, it's job is to keep the throttle from lagging behind when you punch it, at lower RPM's and a picture of my boat for good measure. Thanks everyone!!!

[Beantown]

Hello everyone, I am just updating my post, because I thought my problem was fixed, I was not happy with the speed I was getting, and I thought I was noticing some misfiring at lower rpms, so I thought it could only be the CDI, or coils, stator, etc. So I found one online and was going to test my coils, and the cdi, however when I pulled off the cover, I discovered that I had mouse damage to my wires. I believe this happened years ago, before I bought the boat, and this has been my problem all along. The boat sat for at least three years before I got it, now this is my third year working on it, and this boat has only been in the water less than ten times in the last three years, so I am so happy to finally find the rest of my problem. Two of my positive side coil wires were bare and touching, and I probably was not running on all cylinders, or they were firing at the wrong time. Also several ground wires were chewed, and the two sensor wires to the cooling water sensors. I have fixed the wires for now, and plan to do a permanent fix over the winter, but anyway took it out and hit 59 mph immediately and 5900 rpms at WOT. now I am finally getting somewhere. This was a big discovery for me, and I want to thank everyone for their help. Now I can get this motor propped! This is what I found.

[JoePA]

Sometimes the road to victory is a long and difficult one BUT in the end the victory is yours and you earned every bit of it. Troubleshooting can be a pain but you learn so much about the engine that your confidence in the motor only gets better. Congrats on finding the issues as well as it running better than ever. Good looking boat... Hard to beat an old Champ!

[billnorman1]

It's hard to troubleshoot mice. They run so fast it's hard to get a meter lead on them, much less two.
Glad your boat is running well again, those old 2 stroke Suzy's were absolute screaming machines.