1982 Suzuki DT140 Engine Troubles

grubkidd

Recruit
Joined
Jun 16, 2014
Messages
2
~~Hi all,
I am having engine issues with an engine I bought recently on a 16foot Haines Hunter. The engine is a 1982 Suzuki DT140, the engine idles fine but when WOT, the engine in the water will not rev past 3100rpm and struggles to get onto the plane (approx. 16 Knts). when at WOT the engine will run for about 40-55 seconds and then splutter and die, but will re-start easily. Under no load (on trailer with water muffs, the engine will hit 5500rpm and sounds smooth)
So far I have carried out the following:
Flushed the tank, checked the vent and fuel pickup,
replaced all fuel lines to the fuel pump including new in-line fuel water separator, primer bulb.
rebuilt the fuel pump with new diaphragm's, new fuel strainer,
Removed, cleaned and put rebuild kits through all 4 Carbies, set all floats to service manual recommendations
new Spark plugs,
Checked Compression, #1 115, #2 115, #3 120, #4 115
When I run the engine, it appears to be running very rich, and a lot of black oil residue is coming from the top of the leg and even at idle the engine is quite smokey. the engine is pumping lots of water.
I do have the manual for the engine and have gone through a lot of the trouble shooting, but I am at a loss as what to check next.
Cheers
 

grubkidd

Recruit
Joined
Jun 16, 2014
Messages
2
Sorry I forgot to mention that the 2 top spark plugs are dirty and oily and the bottom 2 are clean after a run.

Cheers
 

surreel

Recruit
Joined
Jul 25, 2014
Messages
1
i would check the water pump/exhuast seal. sounds like the rev limiter is keeping it under 3000. the engine could be running hot. the pisser is not a true indication of water flow either
 
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