Suzuki LT 185 runs, dies, wont start till cool

har_v · 12-13-2011, 08:19 PM

I have a suzuki lt185 that starts on the first or second pull, idles great.
Runs for 10-15 min then after begins to idle poorly. Eventually dies.
Won't start for about 15 min till it cools.

The carb has been off and rebuilt.
Pretty sure this is an electrical problem. Something breaking down with heat. Coil? Where would you look first?

If you keep trying to start it, the plug will foul and you might as well throw it away. New plug and it will start again. Keeping NGK in business.

Advice really appreciated.

higganator · 12-21-2011, 09:47 AM

Check your exhaust valves and make sure they are not to tight. This will cause a hard start or no start when engine is hot. Suzuki uses coated valves. If the coating wears off
the valve face it will cause the valve to tighten up. If you adjust them and the problem comes back the valves will need to be replaced to stop the problem. Also check compression an timming.

har_v · 12-29-2011, 05:47 PM

Thanks for your response. Rocker clearance on valves was within spec at tdc on compression stroke. Valves seem to be seating and with compression over 150psi....not great but ok I would think.

I have inspected more since my first post....but wheeler still has the same problem.

Will start and idle. As it warms up (within 15 mins of idling or driving) it gradually idles rougher. I can keep it running by gradually turning in the idle adjustment from two out (spec) (opening for more air), until it goes all the way in.
When engine stalls, plug is black with carbon, suggesting running rich.

Timing is not off (pulled cover and checked). Gas system is clean.
All coils were within spec (hot or cold).

Have been though the carb....set float and replaced needle and seat.
Currently cleaning it again, because I am out of ideas....

Really would like to figure this thing out.....

crazylt185 · 03-29-2012, 07:32 PM

try changing the plug wire itself or maybe your plug is not the proper one? maybe you got a clogged muffler or a headgasket leak that starts to leak when warm check the compression once its warm also the pullstart decompressor maybe loose or stuck open when warm just sending out suggestions mine wont idle when cold but will when warm so i got to adjust my jets for the weather maybe you have that same problem to hot or to cold also try the winter choke on right side of carb get back to me

Rockfrog · 03-30-2012, 03:21 AM

150psi is quite low for these motors ... 220psi is normal and IIRC the low limit is 165psi (as in rebuild time). They are a very high compression engine.

edwinmaviles · 03-30-2012, 06:28 AM

I had the same problem with my 1990 lt-f250 quad. I replaced the ignition coil and that fixed my problem.

ridgerunner · 03-30-2012, 06:40 PM

the book says compression is 143 - 199 so you are at the bottom end of it. And It is common for the coil to start acting up when it gets hot. Replacin git could be a quick fix. $30 e-bay

stu · 03-31-2012, 02:27 PM

i also have '86 lt 185 with same problem Har V has. ran super, then developed this problem overnite. runs like a champ, then dies when heats up. have done all that has been suggested. will keep checkin with HAR V to see what he does to fix. or will share if i find it first!!