suzuki dt 140 1981 problems

daritzzz · May 30, 2003

Hello, Sorry for the Suzy-fans, but i have had already many problems with it,bad starting,running with 19 pitch prop max 5200 rav's on 17 ft Abbate. This winter I cleaned carb's and jet's , checked reed valves( was oké).I thought I would find the problem but it was all oké(clean).first test was oké even better, few ours later only 3/4 throttle, full he was stalling

now, he won't push the boat, no power. it start good. sometimes a "sneeze". I renewed sparks,kill-switch, fuel line no extra filters anymore (pump oké),all sparks work and I have a compression of 9-9.2 bars(oké I guess) Does anyone now the spec's for spark timing and timing in advance and by how many rav's??? The screws in front of the carb's, are they for the mixture air-benz only at iddle speed?? And what's the difference between the dt115 and dt140?? I've ordered a repair manual 2 weeks ago but it did not yet arrived.And it is now good weather here in Belgium

Thanks already and maybe you've spared a suzi from the scrap

Greetzzz from Belgium Tirett

JB · May 31, 2003

Re: suzuki dt 140 1981 problems

Hello, Tirett. You may have more than one problem. Go to www.outboardrepairs.com and look up power loss and wont start. You will find lots of troubleshooting advice there. Let us know what you did and what happened. Good luck.

daritzzz · May 31, 2003

Re: suzuki dt 140 1981 problems

Thanks, I guess timing is not correct(my fault), I checked timing at iddle speed(900ravs): it is at top of first cylinder. Timing in advance at what rav's and how many degrees?? I also found out that the fuel connector to the engine leaks when i continue pushing the bulb, can this cause the problem also??? At high ravs the carbs throw back some mixture but is not backfiring,is this normal? I'm going to check synchronisation of the carbs The screws lean/rich on the carbs, is it only for mixture at iddle speed? I hope that the repair manual will be soon here than i can adjust everything what never happened in these 5 years I own it. Thanks for any help Tirett

jim dozier · Jun 2, 2003

Re: suzuki dt 140 1981 problems

Get a manual. The screws on the carburetor are for the idle mixture only. High speed has fixed jets. Although you may have more than one problem the sneezing sounds like it is running lean. Yes the leak in the fuel hose is a bad thing and could contribute to if not cause your problem. If your carb is slighty dirty in the jets and you have an air leak and your idle mixture is set wrong you would have the symtoms that you describe. When the carbs were "cleaned" how exactly did you "clean" them. You need to remove them completely disassemble them, soak them overnite in carb cleaner, blow the jets out with compressed air, and install rebuild kits and reset the floats and idle mixture screws. Idle mixture should be 1 1/2 turns out from lightly seated to start. Set idle to 700 rpms, tune each carb separately to best idle and then open mixture 1/8 turn more, reset idle speed to 700 rpms, then do next carb.

daritzzz · Jun 2, 2003

Re: suzuki dt 140 1981 problems

Thanks for the reply jimd, I'm still waiting for the manual(must come from usa with airmail), hope it will be here soon because in a few weeks we go on holiday. I've removed carbs, disassembled them and cleaned al jets, checked floating valves and adjust fuel level. I also checked the reeds. Guess I have to do it again because I've ran engine without inlet silencer and maybe sucked up some foam from the cap and block one or more jets.(common problem of this engine I've read here) Because at first ours he was running fine,after not. seems like 3 sparks are used, one is almost new. But I guess it is working because when I remove its spark-cap and put back, ravs go up for a second. I'm going to remove the foam, it is there probably only for insulation of engine sound, or isn't?? I will set idle mixture as you described. What do I do with the others cylinders when I adjust 1 carb at the time(sparks out or no firing to them) Is it possible to turn the reeds to have better closure, or must I leave them as they are? Have you any sugestions or specs for firing, because I've messed with it (stupid me

). Greetzzz Daritzzz

jim dozier · Jun 3, 2003

Re: suzuki dt 140 1981 problems

The foam is for sound and if its deteriorating, just remove it. Before you do anything else, replace the leaking fuel connector with a new one, these will cause problems and may confuse subsequent tuning. If a reed isn't seating flat replace it, don't turn it. Set idle speed to 700 rpm. Adjust 1 carb at a time as I described before. This may require resetting the idle speed back down to 700 rpm. Then do the next carb, until they have all been done. If necessary repeat all carbs one at a time for one more adjustment. I have a Suzuki DT85 and the idle speed is set with the timing not the carb. I don't know if yours is similar or different. Each engine is probably different for the timing and synchronization of timing and carb linkage (link and sync adjustment). This is where you need a manual. Bon chance.

daritzzz · Jun 4, 2003

Re: suzuki dt 140 1981 problems

Hello Captains, Today I looked with a camera in the cylinders through the plug-holes. What I saw was not nice, cylinder 3 has water on it(piston 3 look like a nailbed, so I guess it was already leak a long time ago), other ones had a rusty-color. All 4 have also scores, which I saw with the camera, but I can't realy see how bad. Although I did winterise it in the last 5 year, I don't know what the story was before. So I must remove the head to change the gasket anyway ,than look good and feel the cylinder walls. Maybe it needs to rebuild or at least a honing job. That's the reason for her"the Suzy

" poor performance all the time,allthough she ran oké but with that boat and horsepower it must fly

I hope I'll get the parts in time because here in Belgium "Suzuki-marine" is hard to find(seems all over the world). All these things I will do before i'm going to adjust anything. This is a great forum, I've learnd "read" a lot here. And maybe I was still loking for problems in carbs and timing. Thanks to all Greetzzz Daritzzz PS STILL WAITING FOR REPAIR MANUAL...

daritzzz · Jun 7, 2003

Re: suzuki dt 140 1981 problems

Hello, I took the head off, no bolts broken

only the cylinder with the leak(3) has a scored place (3/4"-1/2")you can feel by hand. The rest looked better as I thought, but I'm still going to rebuild the powerhead(i've found a great suzy-mecanik and he can deliver all the parts i need)

Are there any items i'll have to check or look for sure??? bearings crankshaft,piston,-rings,... Going to clean carbs also I'm waiting to rebuild untill i have the repair manual I also do wonder what the meaning is off a little hole 3mm just ubove exhaustoutlet(in each cylinder) does anyone knows it?? Greetzzz

daritzzz · Jun 17, 2003

Re: suzuki dt 140 1981 problems

Hello, Still not have the manual(4 weeks), but i've started already. Wanted to renew *3 and *2 piston(oversize) and bore them, but pistons are not in Belgium( if they have them in Japan, it takes 3 weeks to get them here

like the manual

). I'm going to hone all 4 and place pistons back,put all together. I've found a possible cause for my problem, I've had rebuild the carbs with liquid gasket.

First test was oké, than a piece of the gasket loose and get stuck in mainjet

. Going to clean carbs,jets and put new gaskets all over the engine. They are not hard to find because suzuki made it until 1995, only difference is that the connecting rods are fixed on the crankshaft(86-95).Mine is an 81 and can unbolt them. Hope I can get it all fixed before July I'll keep you in touch Tirett

Yepblaze · Jun 17, 2003

Re: suzuki dt 140 1981 problems

If that foam under the hood is deteriorating, get it outr of there along with any leftover sand looking particals of it. The WILL find their way through the carb bowl vents into the carbs and reek havack. They settle out, then at any time get sucked up in main jet(s) only to fall back to bottome of bowl if you try working on something. Then 5 minutes (or whenever random time) they clog the jet again and you learn it still not fixed again.

daritzzz · Jun 17, 2003

Re: suzuki dt 140 1981 problems

Oké Yepblaze, I'm going to remove the foam

daritzzz · Jun 23, 2003

Re: suzuki dt 140 1981 problems

Just bought Mercury 150 efi with new powerhead. '98, great engine!!! I rebuild Suzy after holiday. Greetzz Tirett

daritzzz · Jun 23, 2003

Re: suzuki dt 140 1981 problems

Just bought Mercury 150 efi with new powerhead

. '98, great engine!!!

I rebuild Suzy after holiday

. Greetzz Tirett

daritzzz · Jun 29, 2003

Re: suzuki dt 140 1981 problems

Yesterday I've tried the efi on the lake. Running great,iddles very quit and run much much better than old Suzy. Water was little rough so I could not try to go top, but fully trimmed in, the boat goes 60mph, should be 10mph more in ideal situations, trimmed and lifted up (i hope)

. Now I hope I wont crack the boat. Wednesday we leave for holidays in Croatia Greetzzz Tirett

suzuki dt 140 1981 problems

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