1985 DT55 runs in tank but not on lake

wrolson60

Cadet
Joined
Aug 10, 2004
Messages
7
1985 Suzuki DT55 sn 502753. Bought 2 weeks ago, was laying flat on garage floor for one year. Was told it ran fine when stored.<br /><br />Replaced spark plugs, rebuilt carbs & blew out everything I could with compressed air. rebuilt fuel pump, pulled off lower unit and inspected, all looked good, impeller looked new, lower unit oil clean, no water evident in it. Gears all looked good. Refilled lower unit with new oil anyway. Filled oil injection tank with new oil, verified oil filter was not restricted but did not replace it. Cleaned fuel filter and checked all fuel lines for cracking, all looked good.<br /><br />Problem: Motor will start, although very cold blooded, and idles good on muffs and in tank. Can rev up fine at home, even in gear. When I take it out to the lake it starts fine but in gear it has no throttle power. If I manually hold the choke plates almost closed then it would rev up a little but still no power at any throttle.<br /><br />I have taken the carbs apart 3 times, cleaned and blew out with air again but still seem to have the same problem. It sure seems like a fuel delivery problem but cannot figure out why when everything seems fine.<br /><br />Any Ideas?
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: 1985 DT55 runs in tank but not on lake

check the timing advance<br /> there is a good chance the TPS switch is not working or disconnected.<br /> good luck and keep posting
 

jim dozier

Lieutenant Commander
Joined
Jan 8, 2003
Messages
1,970
Re: 1985 DT55 runs in tank but not on lake

Rodbolt, did they have TPS switchs on 1985 Suzukis?<br /><br />I was wondering if in taking your carbs apart so many times you have got the sync-n-link with the ignition timing messed up. Sounds like he's running a tad lean. When you had the carbs apart did you replace the float valves and check the float height?
 

wrolson60

Cadet
Joined
Aug 10, 2004
Messages
7
Re: 1985 DT55 runs in tank but not on lake

When I took the carbs apart I replaced only the gaskets and needle & seat. Floats looked fine and don't show any signs of soaking up fuel and don't sink. I did adjust the float settings based on the Clymer manual. I also adjusted the linkage following the Clymer manual process. As for the switch question. There is a switch connected to the center carb, the manual only explains about checking the switch for continuity but says nothing about adjusting the setting. This switch has no electronic adjustment but the mounting bracket is slotted on the upper screw. I am wondering if this could be my problem however I have yet to find any information on where to adjust the positioning of the slotted adjustment. <br /><br />Anyone have suggestions on how to know where to move this switch angle too?
 
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