Suzuki DT 140 maintaining power

mlm1977

Cadet
Joined
Sep 26, 2009
Messages
6
Ive got a 1999 Suzuki dt 140. When I first put it in the water it runs great, but after a period of time it is like it loses power. Wont go above 2500 to 3000 rpms. No sensor lights come on, and the motor never quits running, it just wont pick up speed. 8 mph no matter how much you push the throttle. Any advice would be greatly appreciated.
 

Marion Moore

Petty Officer 1st Class
Joined
Feb 6, 2005
Messages
200
Re: Suzuki DT 140 maintaining power

It sounds like the rev limiter is kicking in but with no alarm it is hard to be sure. This is troublshooting from the hip which is not advisable but somethig to check would be the oil filter found in the oil flow sensor. I took mine off, back flushed it with a spray of WD-40 and was shocked at the amount of crud the filter had caught. No way to know if this is the problem but something worth doing if you have never done it.
 

phwrd

Petty Officer 1st Class
Joined
Jul 30, 2007
Messages
294
Re: Suzuki DT 140 maintaining power

Is this motor new to you ? What has been done to it ? Carbs cleaned, rebuilt, Oil Injected or Bypass ?

The more infomation you give, the more knowledgable the answer.
 

mlm1977

Cadet
Joined
Sep 26, 2009
Messages
6
Re: Suzuki DT 140 maintaining power

Thank you both. Yes the boat is new to me. I purchased it at the end of last summer. The motor is EFI, it is oil injected. Only has estimated 130 hours. To my knowledge nothing out of the ordinary has been done. I spoke to the mechanic who did the work for the previous owner he told me he never did anything other than a regular tune up. Ive gone through the fuel symtem checked for leaks. Just had a new rectifier put on the motor. Ive replaced all spark plugs, replaced the batteries in the boat. Last week I ran the boat wide open for about fifteen minutes then slowed down when I came in a no wake zone, after passing through I tried to throttle back up and no power.
 

deejaycee_2000

Captain
Joined
Mar 28, 2006
Messages
3,447
Re: Suzuki DT 140 maintaining power

Sounds like a oil issues, either the oil filter sensor, or the oil level switch, I always keep my oil reservoir at 3/4 ....
 

mlm1977

Cadet
Joined
Sep 26, 2009
Messages
6
Re: Suzuki DT 140 maintaining power

Thank you all for your help, I will give it a shot. If anyone else might have some advice im all ears. Thank you
 

thecow18

Cadet
Joined
Nov 16, 2009
Messages
16
Re: Suzuki DT 140 maintaining power

I had a similar issue where my engine would not run over 2500 rpm. I replaced both the fuel/water seperator filter and the fuel filter and that fixed the problem....
 
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