1988 dt150 problems

[baja79]

still having problems..rebuilt powerhead.engine runs really bad. misses through prop at idle. while checking plugs port side plugs are wet and black,on starbord side top plug wet and black but bottom 2 plugs are dry but black.pistons were installed properly.carbs gone through.new cold start assem.new plugs of proper heat range. tank cleaned.50:1 mix in tank plus oil injection hooked up for first tank on new motor.getting spark to all 6 plugs.... help ,before i pull the rest of my hair out !!!!!!!! thanks rick

 

[jim dozier]

Re: 1988 dt150 problems

The reasons why it would run bad.<br />1. compression. Have you checked it after the rebuild?<br />2. Spark. You said it was getting spark on all 6.<br />3. Timing. Since the engine had been all apart is the timing set right? Is this a mechanical timed or electronic timed engine?<br />3. Fuel. Most obvious is carbs. Have they been rebuilt, properly? Fuel pump. Air leaks. Reed valves.

 

[baja79]

Re: 1988 dt150 problems

carbs were rebuilt right... i even took them apart for the second time just to be sure<br /> has 160 to 165 in all cyl.<br /> timming is fixed but that is what i think it is but have know way of checking because my manual does not show where the fixed pointer is.it should be on the starter nose cone but mine doesnt have one. never came with one<br /> fuel pressure is at 4lbs. i even took exhaust covers off thinking they were letting water in but everything was sealed great..<br />thats why i'm pulling my hair out..any help would be greatly appreaciated..... rick

 

[jim dozier]

Re: 1988 dt150 problems

My first thought is that your ignition timing and carb synchronization is at fault. The synchronization should be set up as shown in the manaul as every engine (and year) may be different. On my 1987 DT85 the timing is mechanically advanced and needs to be in sync with the carb butterflies. I will check my manual tonite and see what yours is supposed to be.