New guy w/ question... Zuke DT225 help...

rockyraider

Recruit
Joined
Feb 15, 2009
Messages
2
I'm looking for help with adjusting a Suzuki throttle. I'm not sure if the issue is at the control or at the engine. Some background:

The engine is a 1996 DT 225 EFI on an '83 Grady White 204. The boat accelerates fine but when you pull back at say twenty to just under forty mph, the throttle cuts back as if you pulled the throttle control back. You then give it some throttle to get the speed back up and it runs fine. This does not appear like its the engine, its almost like something is overly touchy. The engine runs great from zero to fifty mph plus.

The best way I can describe it is this: Take off, get boat on plane, continue accelerating to say fifteen to thirty five mph or so, pull back just a bit to maintain your speed (like you pulled a skier up and want to maintain a sking speed), and the throttle is overly sensitive so that the engine cuts way back. Give it more throttle and the boat jumps forward and picks right back up and continues accelerating. This causes for a very jerky ride when you are trying to maintain a lower speed since the control acts like its overly sensitive and either wants to cut the engine way back or run at over forty mph. You can not hardly run between say 20-40mph. The engine is not cutting out, you just can not hold the throttle at these speeds. You can actually accelerate to say forty or so mph, let go of the control, and if the water is rough it will actually cut back on its own after hitting a couple good waves. The guy that I bought it from told me that he had the throttle control adjusted this way as a safety feature in case he was knocked away from the controls but I'm starting to have my doubts.

I don't believe that its the engine as it runs, idles, gets on plane, and accelerates fine. The compression is fine. The controls are two years old and were purchased from Suzuki. I did not install them as they were already on the boat when I bought it. Its like the throttle adjustment is not right at the accelerator control. I want to get it fixed so that I can ski/tube this summer and forty plus mph is no good for fun at the lake. There are two adjustments that you can and the one that sounds like it would help is the throttle tension adjustment. Any advice on this issue or anything else that I should be looking at? Thanks a bunch.
 

cousinabe

Senior Chief Petty Officer
Joined
Nov 13, 2001
Messages
765
Re: New guy w/ question... Zuke DT225 help...

Sounds like it might be a faulty TPS.
Check the resistance of the throttle position sensor and make sure there are no dead spots or abrupt fluctuations while testing.
 

rockyraider

Recruit
Joined
Feb 15, 2009
Messages
2
Re: New guy w/ question... Zuke DT225 help...

Any suggestions on how to test this? I'm a first time boat owner so any and all help is greatly appreciated. Thanks a bunch.
 

JUSTINTIME

Captain
Joined
Sep 2, 2006
Messages
3,284
Re: New guy w/ question... Zuke DT225 help...

you want 225-275 ohms when in neutral
 
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