DT200 Guru's,
There's got to be a DT tech/owner that's had this issue.
Engine is a 1989 DT 200K with about 700hrs and has been in the family since new. Always been on our Barefoot Sanger. The only problem this engine has had are a few bad sensors till now.
Just a few seasons ago the engine started this intermittent loss of about 30% HP when we get on plane. This problem hasn't gotten worse nor better. It always does it after I get on plane and back off the throttle but not all the time, then can only get 4000 rpm max. Never had any alarms audible or visual. All the warnings lights are operating properly. She starts up every time, purrs like a kitten and overall runs great with this one exception. This has been going on for the last two seasons. Had it in and out of the only Suzuki shop here in San Diego about 4 times trying to diagnose--great techs, just a very frustrating problem. I consider myself a great tech with countless hours of boating and professional troubleshooting experience but I've run out of ideas and I know there are guys with way more DT knowledge than I do on this site.
Here's what we found out:number 5 and 6 cylinders are not properly firing. We know this because after several hours of running with new plugs the bottom two look shiny and new with fuel and a little oil on them and some carbon, the other four look crisp and flawless--a little gray with very little carbon. Also, when the engine drops HP the timing drops from full WOT at 20 degrees full advance down to around 5 degrees--don't ask how we figured that out, probably broke half dozen laws doing it. Anyway, based on that, we knew it wasn't a fuel problem but had to be a simple glitch in the ignition system that's controlling the timing.
Here's what's been done so far: new oil flow sensor, water flow sensors, throttle position sensor switch, CDI unit, ignition control unit, fuel filters and all new plugs. The most challenging part is trying to induce and isolate the problem since it happens only at higher rpms and typically under load--tinkering with 200 horses at 30+ mph is scary but I can say it's been done. Any ideas would be most appreciated.
Thanks,
Mcgryger
There's got to be a DT tech/owner that's had this issue.
Engine is a 1989 DT 200K with about 700hrs and has been in the family since new. Always been on our Barefoot Sanger. The only problem this engine has had are a few bad sensors till now.
Just a few seasons ago the engine started this intermittent loss of about 30% HP when we get on plane. This problem hasn't gotten worse nor better. It always does it after I get on plane and back off the throttle but not all the time, then can only get 4000 rpm max. Never had any alarms audible or visual. All the warnings lights are operating properly. She starts up every time, purrs like a kitten and overall runs great with this one exception. This has been going on for the last two seasons. Had it in and out of the only Suzuki shop here in San Diego about 4 times trying to diagnose--great techs, just a very frustrating problem. I consider myself a great tech with countless hours of boating and professional troubleshooting experience but I've run out of ideas and I know there are guys with way more DT knowledge than I do on this site.
Here's what we found out:number 5 and 6 cylinders are not properly firing. We know this because after several hours of running with new plugs the bottom two look shiny and new with fuel and a little oil on them and some carbon, the other four look crisp and flawless--a little gray with very little carbon. Also, when the engine drops HP the timing drops from full WOT at 20 degrees full advance down to around 5 degrees--don't ask how we figured that out, probably broke half dozen laws doing it. Anyway, based on that, we knew it wasn't a fuel problem but had to be a simple glitch in the ignition system that's controlling the timing.
Here's what's been done so far: new oil flow sensor, water flow sensors, throttle position sensor switch, CDI unit, ignition control unit, fuel filters and all new plugs. The most challenging part is trying to induce and isolate the problem since it happens only at higher rpms and typically under load--tinkering with 200 horses at 30+ mph is scary but I can say it's been done. Any ideas would be most appreciated.
Thanks,
Mcgryger
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