DT30C locked timing no advance

[JWC32181]

I have a '93 DT30C that has half power, timing is locked at 10BTDC and doesn't change. Have shop manual but can't find procedure or specs to test throttle sensor, suspect that may be problem. Anyone have that procedure and specs? Any other suggestions for what would cause this?

[Solarman]

If you have the suzuki shop manual, it would tell you this motor has 3 ignition timing coils, 1 gear counting coil, the throttle positon sensor, the oil flow switch/sensor, the heat/temp sensor, and neutral safety switch. All of the previous mentioned items can affect how your motor runs. Your suzuki service manual should explain each, and tell you how to check each.
If you have some other manual, it probably won't tell you?

Good luck, post back when able.

[JWC32181]

Yes it explains them & how to test all except the throttle sensor, can't find test or specs anywhere- unless they put it somewhere other than ignition, fuel or tune up- or i just missed it!
I do have suzuki manual.
All else seems to test good, pointing to th sensor or IC?? Module is not available so hoping it's the sensor!

[Solarman]

What do you mean by "half power"? Is motor in "safe mode"? Most sensors/switches cause this mode.
Do you have spark on all cylinders? Again, "safe mode"?
Does engine have suzuki monitor guage? Lights flashing?
Might check compression? Low compression can cause poor power/running.
If you have spark on all plugs, has motor been sitting up for an extended period of time? Probable fuel problem (fuel pump or carb dirty)?
Does motor idle smoothly? At what rpm/ throttle positon does motor act like it is not running as it should?
As these temp sensors/oil-level/ water & oil flow switches do affect/interrupt spark to cylinders to limit rpms (safe mode).
Timing is controlled by gear counting coil, TVS and control module (IC) (timing is IC adjustable). The TVS changes timing only in 3 or 4 positions, and the manual (my manual) does instruct on testing. Located in "electrical and ignition" section, under Throttle Valve Switch. Can check with pocket ohm meter per suzuki manual.

If you explain exactly how this problem occurred, what happened when this problem started, it could lead to quicker diagnostics of correction?

Good luck, post back when able, and answer questions listed above.

[JWC32181]

Only running about half speed, 3300 RPM, won't plane boat out. Used to take off good and plane out.
Don't think it's safe mode unless that causes timing to not advance, timing light shows 10 deg BTDC all the time from idle to full throttle.
Spark on all at WOT, idles good, compression good.
Tiller motor, no gauges, does have red warning light on front but not coming on.
Came on suddenly- was running fine then next weekend this.
No missing or roughness, just gutless.
I think this is a OE Suzuki manual but may not be best one, it's in PDF I found on the internet. Has Suzuki logo and says Suzuki outboard workshop service manual, all motors 2-225 HP, Years 1988-2003 on first page. But I looked again and nothing in " ignition and electrical systems" section 5 in this manual, for Throttle Valve Switch.
Can you describe testing and what it should test at?
Thanks for your help

[Solarman]

Sorry for the delay getting back to you. Tried to upload pic of page didn't work. If you send me an email address, i can send it to you.

[JWC32181]

Thanks, but I got it fixed. Was the throttle sensor, it had no continuity through any leads. I did find a manual that showed how to test & set it, had no voltage signal output.
Timing advances again & runs like it used to!

[Solarman]

Glad to hear. Happy boating!

[cxgibson]

Thanks, but I got it fixed. Was the throttle sensor, it had no continuity through any leads. I did find a manual that showed how to test & set it, had no voltage signal output.
Timing advances again & runs like it used to!

Any chance you recall what the procedure for testing the throttle sensor? I am having the same problem and I am also having trouble finding a manual that shows how to check the TPS.