Suzuki dt55 trembles, lacks power, help

fish2day

Petty Officer 3rd Class
Joined
Nov 28, 2010
Messages
81
1989 DT55HP stored for 2 years. Carbs were varnished up so I removed and cleaned with carb cleaner. Ran good in water for 15 minutes, then water sensor went out. I replaced the water sensor and oil sensor.
Now, starts easily and idles good, but when accelerating it trembles and lacks power. It will plane out and reach about 20-22 mph. All three cylinders are firing with compression. Does this sound like a carb problem lacking fuel? What will cause the engine to tremble at half throttle? Fire or gas ?? Thanks for your help.:confused:
 

mphelle8vld

Petty Officer 1st Class
Joined
Aug 17, 2005
Messages
321
Re: Suzuki dt55 trembles, lacks power, help

Assuming this is the 1991 motor in your other post, give us the serial number so we know what year it is. Take the motor to a shop for a leakdown test or to a friend with a compression gauge and post the numbers.
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
8,851
Re: Suzuki dt55 trembles, lacks power, help

loss of spark, too much fuel, or too little fuel can cause the problem.
You need to do some testing to find out or at least eliminate some.
Timing light will help you see is it is dropping spark if moved to the different plug wires and if the timing is correct.
leaking fuel pump can cause extra fuel into crankcase
Spraying a fuel/oil mix into the carbs while problem is occurring will let you know if is lack of fuel, just be careful as running too lean can hurt the pistons.
 

fish2day

Petty Officer 3rd Class
Joined
Nov 28, 2010
Messages
81
Re: Suzuki dt55 trembles, lacks power, help

Assuming this is the 1991 motor in your other post, give us the serial number so we know what year it is. Take the motor to a shop for a leakdown test or to a friend with a compression gauge and post the numbers.

Yes, I was assuming it was a 1991, but after running the numbers it is a 1989. Also Assumning you know outboard engines, you should know there are little difference between a 1991 & a 1989. The compression is good as I stated. I have worked on engines for years, just not outboards. The problem is either in the firing or fuel. I was looking for advice, not critical statements.
 

infideltarget

Master Chief Petty Officer
Joined
Aug 30, 2010
Messages
802
Re: Suzuki dt55 trembles, lacks power, help

What will cause the engine to tremble at half throttle?

Maybe it is trembling 'cause it's skeered. Could be too 'fraid to go full throttle. It's just little...

:D sorry...couldnt resist. no offense intended :D
 

mphelle8vld

Petty Officer 1st Class
Joined
Aug 17, 2005
Messages
321
Re: Suzuki dt55 trembles, lacks power, help

Yes, I was assuming it was a 1991, but after running the numbers it is a 1989. Also Assumning you know outboard engines, you should know there are little difference between a 1991 & a 1989. The compression is good as I stated. I have worked on engines for years, just not outboards. The problem is either in the firing or fuel. I was looking for advice, not critical statements.

Before responding, I reflected on the thousands of posts made by Rodbolt on this forum over the years.... Good luck with your motor.
 

sk

Seaman Apprentice
Joined
Feb 25, 2010
Messages
39
Re: Suzuki dt55 trembles, lacks power, help

try recleaning the carbs again. if it was that bad the first time maybe there was more. I have always loved how "friendly" everyone is on this site
 
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