Logo
FULL SITE MENU

Tohatsu 140 2 stroke

Carbs cleaned last week timing hasn't been touched as far as I know bought motor about a month ago compression is 120 on all 4 also checking yesterday the coils appear to have a really weak spark
 
I used spray carb cleaner and air hose all passages seemed clear and clean no trash at all in carbs when disassembled started checking timing rod length and throttle linkage just running thru everything I know without adjusting anything until all has been checked and double checked I don't want to overlook the obvious problem and so far I haven't found anything but then again I could be overlooking something and that's what brought me here and all the help and advice is greatly appreciated the tohatsu dealer here in GA won't even look at it because they only deal in smaller o/b
 
You need to a proper overnight soak in carb dip, followed by a thorough blow out of all passages.
 
Sorry I haven't been around for a few days been working 16 hour days I will soak overnight and see what that does adjusted timing rods to the length I found on another website not much adjustment was needed all appears good there now I will check back in a couple of days and let you know what carb soak changes is it possible for it to be electrical and not fuel related again I say thank you
 
The weak spark needs to be addressed. Have you done a spark gap jump test? This motor should have a 1/2 in sharp crackle of blue white "lightning like" spark. Conduct your spark test with all plugs out and a fully charged battery with nice fast cranking speed. If you have a multimeter, the voltage of a fully charged battery will be 12.65 volts.
 
Last edited:
Not yet batty is new and fully charged checked with meter waiting for spark tester to arrivewill post results only 1 cyls appears to have good spark other 3 appear weak that's just checking with a new plug ordered spark tester thanks for the input all help is greatly appreciated
 
I checked the spark it has a good 1/2 inch jump with good spark carbs soaked overnight and blown with air hose it seems to be running better but just doesn't seem to be running the way I think it should maybe it is just me still looking all input and advice is greatly appreciated
 
Did you physically clean out jets with a welding tip cleaner? Soaking and blowing sometimes falls short.
 
timguy said:
Did you physically clean out jets with a welding tip cleaner? Soaking and blowing sometimes falls short.
Click to expand...

No. Never push anything in the passages. Micro scratches will cause weird mixtures that can only be fixed with a new carb.
 
Yes, care needs to be followed. The reason I use welding tip cleaners is they are softer material with gentile corragations. They will remove the oxidation and deposits when used in conjunction with a good carb or throttle body cleaner. Motors today are engineered to run as lean as possible, any restriction in jets can cause damage. Why? If you have multiple carbs and one is running lean, what happens? Since 2 strokes have their cylinders isolated, and one cylinder is getting less fuel/oil mixture than the others, (which are "dragging" it up and down without sufficient lubrication), what happens? Bingo, you guessed it......scored cylinder. So if full power isn't being obtained on a motor with multiple carbs, the plugs need to be analyzed....and problem immediately addressed which could be causing it.
 
Here is the strongest cleaner I have found that can quickly soften deposits from rotten fuel and/or contaminants.
 

Attachments

  • Screenshot_20200914-003554.jpg
    Screenshot_20200914-003554.jpg
    113.6 KB · Views: 16
Back
Top