Suzuki DT 30 troubles

M.Magis

Cadet
Joined
May 22, 2003
Messages
28
I recently bought a used 1988 Suzuki DT30. On the first trip on the water, the motor ran great, though it idled a little too high. For some reason, I decided to try to adjust the carbs before getting my manual. After that it ran horribly. After getting the manual, I set the carbs to where they should be, but the engine still runs bad. I pulled the plugs and found that the bottom plug was dry and sooty. I took another trip to the lake and tried making some adjustment. As I run, the rpms are nowhere near where they should be. At a medium to low speed, occasionally the engine will sputter some as it slowly picks up rpms. It will get to the point where you think it's going to run well, then falls back down. When I pulled the plugs after that trip, they were all the same and looked fine. I have spent hours reading through the archives here, and have a few ideas, but I was wondering if I was on the right track. First thing I did was pump the primer bulb. It made no difference, though the bulb will not get hard. No matter how much I pump, it stays the same. Right now I am in the process of cleaning the carbs. My thought was that the bottom carb was getting blocked, therefore the spark plug would be dry and the engine is only running on two cylinders. Does any of this make sense or are there some other things I should be looking at?
 

M.Magis

Cadet
Joined
May 22, 2003
Messages
28
Re: Suzuki DT 30 troubles

Well, I just finished putting the engine back together and trying it after cleaning the carbs and installing new plugs. Either I didn't do something right (very possible), or it didn't help. Bottom plug still appears dry. It looks like it's getting oil on it, but it's not damp like the others. I wasn't able to go past idle, but it just wasn't running as smooth as it did before. I'm fairly new at working on outboards, so I'm not completely sure what to look for.
 

fridays

Petty Officer 2nd Class
Joined
Jan 26, 2003
Messages
126
Re: Suzuki DT 30 troubles

Check compression and get back to us.
 

M.Magis

Cadet
Joined
May 22, 2003
Messages
28
Re: Suzuki DT 30 troubles

Just checked the compression. Good news is, 125 psi in all three cylinders. It's hard to tell exactly how it's running just idleing in the driveway, so I think I'll take it out to the lake. The problem was most evident at low throttle.
 

machu701

Recruit
Joined
Jun 14, 2008
Messages
3
Re: Suzuki DT 30 troubles

when you figure this out,please let me know,i'm going through the same hassle right now,with the bottom cylinder,however mine was running perfect then it just started slowing down getting less and less power ,even suzuki is baffled
 

greenhead1984

Seaman Apprentice
Joined
Feb 4, 2008
Messages
38
Re: Suzuki DT 30 troubles

Were you confident that you cleaned the carbs good? Especially the pilot jet and adjustment screw on the upper right side of the carbs close to the linkage? Sometimes these get overlooked. Just a thought
Good Luck
 

machu701

Recruit
Joined
Jun 14, 2008
Messages
3
Re: Suzuki DT 30 troubles

carbs are perfect ,just ordered some new reeds,i hope this helps,fishing season is hear.
 

jdeerel

Recruit
Joined
Aug 18, 2008
Messages
3
Re: Suzuki DT 30 troubles

Sounds like a problem I'm having, turns out that I am pulling exhaust up into the engine compartment and the first place it goes is into the bottom carb. Plus the engine runs better with the cover off than with it on .....because it gets fresh and and is not re-burning exhaust fumes instead of air. I still need to locate the leak.
 

James R

Commander
Joined
Feb 1, 2007
Messages
2,679
Re: Suzuki DT 30 troubles

Have a DT30 in the shop. Similar symtoms. Plug not wet etc. In this case it was the upper crankshaft seal worn. Sucking air into the crankcase on #1 instead of sucking fuel in. Compression great but no #1 cylinder.
 
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