Suzuki DT90 starting issues

MaddMike07

Recruit
Joined
May 4, 2018
Messages
3
Recently purchased a boat that was equipped with a 95 Suzuki DT90. Motor was completely serviced before the sale. New fluids, new plugs new wires etc. The problem that im having is it will fire right off on the muffs and run for days. Get to the water and back her down, she doesnt wanna start. Ive trimmed the motor up and it fired then dropped back down while running and it does fine. Even after this initial hard start issue, I can have the motor off for hours and bump the key and she fires right off everytime. Its just the initial starting that it absolutely does not wanna do unless the motor is trimmed up. Now, I need to figure out whats really going on, and I cant keep starting this thing trimmed up as we all know it will damage the impeller etc. Compression checks come out at 120,120,130,130. Motor is clean as hell and very well maintained. From reading I could see how this could be a battery issue but im just not understanding how itll start fine everytime after the initial starting.

May I add, the previous owner said ignition key switch went out and he replaced it with a suzuki one, however it doesnt have the push in electric choke on it. I still dont see that playing a factor in it as itll start outta the water but not in. Like a backpressure issue at first or something. Heck what do I know, im here for the answers.
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
9,212
when the motor is set down in the water back pressure is put on the exhaust.
If the motor you have has an electric choke, you need a way to operate it, but you could pull the manual choke instead
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
9,212
take the cowling off and look to see if you have an electric choke and if there is linkage going to a lever you can pull manually
 

lakensea

Chief Petty Officer
Joined
Jan 30, 2002
Messages
542
Recently purchased a boat that was equipped with a 95 Suzuki DT90. Motor was completely serviced before the sale. New fluids, new plugs new wires etc. The problem that im having is it will fire right off on the muffs and run for days. Get to the water and back her down, she doesnt wanna start. Ive trimmed the motor up and it fired then dropped back down while running and it does fine. Even after this initial hard start issue, I can have the motor off for hours and bump the key and she fires right off everytime. Its just the initial starting that it absolutely does not wanna do unless the motor is trimmed up. Now, I need to figure out whats really going on, and I cant keep starting this thing trimmed up as we all know it will damage the impeller etc. Compression checks come out at 120,120,130,130. Motor is clean as hell and very well maintained. From reading I could see how this could be a battery issue but im just not understanding how itll start fine everytime after the initial starting.

May I add, the previous owner said ignition key switch went out and he replaced it with a suzuki one, however it doesnt have the push in electric choke on it. I still dont see that playing a factor in it as itll start outta the water but not in. Like a backpressure issue at first or something. Heck what do I know, im here for the answers.

All Suzuki key switches have the push to choke features.
 

robert graham

Admiral
Joined
Apr 16, 2009
Messages
6,908
Try pumping the primer bulb a few times right before you try to start it.....Works on my C90 Yamaha Primestart
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
When priming fuel bulb it should be done with bulb arrow poiting upwards till feels completely firm, if primed at other position fuel will be delivered at a less amount to carb and could be a factor having issues in morning first cold starts...

Happy Boating
 

MaddMike07

Recruit
Joined
May 4, 2018
Messages
3
Everything with the primer and bulb checks out good. Doing it the right way etc. This is a 1995 Suzuki DT90 and im going to replace the obvious first and go from there. With that being said I guess now I need to know which ignition switch to buy. In parts diagrams im seeing 2 different ignition switch part numbers. Ive seen others switches also that have the terminals on the back of them, im looking for the style that has the factory harness on the back with the snap together style connectors. Any help on obtaining that would be tremendously helpful. Maybe ive been just missing something obvious hopefully.
 

lakensea

Chief Petty Officer
Joined
Jan 30, 2002
Messages
542
Everything with the primer and bulb checks out good. Doing it the right way etc. This is a 1995 Suzuki DT90 and im going to replace the obvious first and go from there. With that being said I guess now I need to know which ignition switch to buy. In parts diagrams im seeing 2 different ignition switch part numbers. Ive seen others switches also that have the terminals on the back of them, im looking for the style that has the factory harness on the back with the snap together style connectors. Any help on obtaining that would be tremendously helpful. Maybe ive been just missing something obvious hopefully.

Just visit your local Suzuki dealer and they will provide the correct ignition switch. There is only one.
 
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