87 DT 150 lost power, no stalls on engage

[jimscriv]

So I've been running this well maintained Suzuki 87 DT 150 this summer with no issues, then yesterday I've got it a 3/4 throttle purring like a kitten and it gradually loses power until it stalls. It starts right back up in neutral and revs nicely, but stalls whenever forward or reverse is engaged. The prop spins while in neutral so being a pessimist I'm thinking that there may be some driveshaft issues (bearings?). Anyways, before I haul the boat out and pull the lower unit, does anybody have any suggestions as to a more simple solution that I'm overlooking?

 

[hankll]

Re: 87 DT 150 lost power, no stalls on engage

I'm no expert, but my 87 dt150 had a loss of power that was similar when I first put it on the water. check spark on all cylinders. You might have no spark on one side of engine. Mine was the 1,5,7 cylinders and was caused by the the low oil warning module not working and that caused the CDI to stop firing all cylinders. Had to disconnect my LOWM in order to get all cylinders firing again. Now I have to check oil tank manually. But it sounds like same condition, in that it would run and "sound" fine until it was in the water and put into gear and then it wouldn't go over 14-1600 RPM's and I couldn't get up on plane or maintain any speed over the 14-1600 rpm's. Beyond that, make sure you have fuel, it could be starving for gas, too. DeeJaycee, would be better help. He helped me out when I was about to pull my hair and thought I might as well use my motor for an anchor. If it is the LOWM, unless you have a parts engine, it cannot be bought any longer to be replaced.

 

[grid]

Re: 87 DT 150 lost power, no stalls on engage

What you describe is NOT the gearcase. The prop is supposed to spin in neutral. I'd look to 1) lack of fuel 2) water in the fuel, or 3) piston seizure. Drain a couple of the fuel bowls from the starboard side to see what comes out. Do spark and compression tests. But DON'T arbitrarily yank the gearcase.

 

[JUSTINTIME]

Re: 87 DT 150 lost power, no stalls on engage

sounds like a fuel issue
check spark and comp also

 

[jimscriv]

Re: 87 DT 150 lost power, no stalls on engage

I'm glad to hear that there are options not involving pulling the lower unit. The gas is only 3 weeks old, and I put 50 gallons in at that time, with about 5 hours run time since, so low or bad fuel should'nt be an issue. I'll try disconnecting the LOWM, check spark, and look in a few of the carb bowls to see if anything nasty lives in there. I don't believe that it'll be a piston siezure as it starts and revs fine, but I guess that a blown ring might be a possibility, and I suppose that a carb rebuild might be in my future. The boat is floating on a mooring in Maine and I live in NH, can anyone tell me the spark plug # for an 87 dt 150?

Jim Scrivens

 

[JUSTINTIME]

Re: 87 DT 150 lost power, no stalls on engage

Ngk Br8hs

 

[hankll]

Re: 87 DT 150 lost power, no stalls on engage

Again, I'm not an expert, but mine with half the cyl with no spark, would seem to rev up ok, but when in gear just wouldn't get up and go. I wasn't sure until I checked spark on all cyl. that I realized why. LOWM was not working and telling the CDI unit that there was no oil so it went into protection mode and stopped 3 cyl form getting spark, removed that LOWM from circuit and all spark was back. But even if you have fresh gas you could have a blockage in one of the fuel bowls main jet, so could be fuel restriction. You just have to check

 

[jimscriv]

Re: 87 DT 150 lost power, no stalls on engage

Well I spent a couple of hours working on the Zuke and may have found the issue with it. I took apart the LOWM and found nothing wrong, so I cleaned the filter and reassembled it. I checked cylinder 1 and got no spark and did get spark on #2, I stipped there and pulled the ignition coil cover off and noted a rather unfactory looking electrical tape wrap on some wires by the upper coil as well as a loose wire. When I unwrapped the tape to see what the wires looked like underneath, the poorly soldered connections came apart. I took some pics of the wires, I have no idea what color wire goes to what component, the colors of the wire are apparent, does anyone have the knowledge to let me know if resoldering these connections is the correct wiring? I'd be happy to email the pics!

Damn Striper season is slipping away!

Jim

 

[JUSTINTIME]

Re: 87 DT 150 lost power, no stalls on engage

 

[JUSTINTIME]

Re: 87 DT 150 lost power, no stalls on engage

on the coil, the black is ground
the black with white dots is positive