Yamaha 115 HP starting problems - HELP!!

[ezzrider]

I own a 1994 115 HP TLRS Yamaha outboard motor mounted on the back of my pontoon boat. Reason I mention the pontoon boat is this makes the front of my motor hard to access. My boat sat for about a year. I recently took off the 2 carbs, thoroughly cleaned and rebuilt them with a Yamaha Carb rebuild kit. I have a Clymer engine manual and followed all the steps for removal, disassembly, cleaning, rebuilding and reinstalling the carbs. Problem is the motor will not start unless I shoot starting fluid into the spark plug holes. Once started the engine runs great. I took it out on the lake and ran it for about 2 hours with no problems. It starts right back up when warm but after sitting awhile it will not start up without doing the starting fluid routine. I have put in fresh 93 octane gas and new plugs. The primer bulb pumps up properly and gas is getting into the carbs. The battery is in good shape and the starter is fine. I have tried starting up using the electric choke and manually pulling out the choke. All my hose fittings appear tight with no air leaks. There must be something simple I am just missing.

One issue I also have is with the Pilot Screw settings. This may or may not point to my problem. According to the manual the pilot screws should be adjusted out 5/8 turn. With this setting the motor will start but runs very rough and shuts off. When I adjusted the pilot screws out to a little over 3 turns the engine runs great but will again will not start after sitting overnight. I have checked and rechecked everything. I am at a loss.

[99yam40]

If it will not run properly at the spec settings then they need to be cleaned better, maybe sonic cleaner if you have soaked them already

[yamatech43]

yep, 99 is right, you can't just adjust the idle screw to several times the spec and say the carbs are ok....i suspect the very very fine idle
passages are clogged in throat....

[ezzrider]

yep, 99 is right, you can't just adjust the idle screw to several times the spec and say the carbs are ok....i suspect the very very fine idle
passages are clogged in throat....

I let the carbs sit in carb cleaner, used cue tips and an air compressor blow out to clean the carbs. Can't imagine after all of that they are not clean? I guess I could take them back off. Is there nothing else that can cause these problems?

[crb478]

I am not sure if you have a choke system on an enrichener system on that motor. If it is a choke system are you sure the throttle blades are closing fully? Is the selonid hooked up?

[ezzrider]

I am not sure if you have a choke system on an enrichener system on that motor. If it is a choke system are you sure the throttle blades are closing fully? Is the selonid hooked up?

It has an electric choke. The electric choke is working propery and I have also pulled out the manual choke with the same issue. The blades are fully closing. When I take off the front cover to the carbs for access I unhook the electric choke seleniod as it is attached to the front cover and use the manual choke lever. It is not the choke but something else. I may just pull the carbs back off later today and see if there is anything else I can do but I believe those carbs are clean. Trying all the things I can do before just taking it to a boat mechanic. With this being a 24' x 8' pontoon boat it is a bit of a pain to transport.

[jtye1973]

It has an electric choke. The electric choke is working propery and I have also pulled out the manual choke with the same issue. The blades are fully closing. When I take off the front cover to the carbs for access I unhook the electric choke seleniod as it is attached to the front cover and use the manual choke lever. It is not the choke but something else. I may just pull the carbs back off later today and see if there is anything else I can do but I believe those carbs are clean. Trying all the things I can do before just taking it to a boat mechanic. With this being a 24' x 8' pontoon boat it is a bit of a pain to transport.

sounds like jets to me