Very high idle when start, then shut down

[soflaguy]

I'm starting a new thread to keep everyone from having to read my past problems too. After getting my '89 85hp motor to start, I had a problem with gas leaking from carb #2 during high throttle before I had a chance to adjust the idle mixture screws. They are set 1 turn out.
I took the carbs apart and cleaned them. Put everything back and started it up. The tach reved up past 4000 rpm's, would surge up and down and then cut out.
I didn't mess with the floats although I did remove them to check the needle and I noticed one did kinda stick. Thought it was ok when I put the float back on. I used a barb cleaner and it did leave my latex gloves sticky. Was I supposed to rinse everything off with water before re-assembly? What would cause so much gas to flow and give me such high rpm's and surge up and down? Its in neutral with the throttle pushed as far as I can when I start it. I can see the choke is working properly.
Thanks in advance.

 

[soflaguy]

Re: Very high idle when start, then shut down

carb cleaner, not barb cleaner. sorry.

 

[jerryjerry05]

Re: Very high idle when start, then shut down

#2 piston controls the fuel pump.Check the diaphram and reeds.
THe valves in the pump could be bad.Replace them and the diaphram.
Do a comp and spark test again.Then check for crap in the carb.You have a small particle filter in line? How about a fuel/water seperating filter.J

 

[soflaguy]

Re: Very high idle when start, then shut down

I was afraid you'd mention reeds so I'm gonna check them and pray while I do it. I'll check the pump and diaphragm today too. Yes, I put a little fuel inline filter in there after seeing specks of something in the carb bowls. I haven't yet put in a water/fuel separator but have looked into them. Can you steer me to an appropriate type? The ones I've looked at seem large and I don't know where to put it along the fuel line. 1989 85hp, 3 cylinder, H model. I want one definitely since I've seen others with water in the fuel problems and I had water everywhere when adjusting it in the canal.
Here's the thing. When I replaced the diaphragm the first time, I've bought a boat that sat in a garage for 5 years or more, the diaphram had a spring that stretched the diaphram, enlarging the bowl I guess. My model is an 'H' model, 856A9H. It's not supposed to have that spring. I do see the spring in a diagram for the '89 85hp 'B' model, L-drive and the '92, 120hp, L-drive. I do not have an L-drive. I suppose I should put the spring back in but do you think that would cause whats happening? Any idea what the spring is for since its only on the L-drives? I'd put the diagrams up in thumbnail but I'm not that computer savy yet. Thank goodness I can manage this site or I would have floated to Cuba by now.

 

[soflaguy]

Re: Very high idle when start, then shut down

Just adding that I also replaced the center check valve and purchased 2 others. So I do have them to replace the other 2 and will do that also. Its just that doing so many things at once, I don't know which makes a difference. Trying to go by the manual. I've got the Seloc and an old US Marine manual for 3 cylinders. It was the #2 cylinder that was leaking so thanks for steering me back to the pump..

 

[jerryjerry05]

Re: Very high idle when start, then shut down

That spring helps the performance of the pump.Put it back in.
The f/w filter should go someplace where it's easy to get to. Lots of people put them in the splashwell.Some under the seat or in the battery compartment.I don't think that's the best place for a gas filter.
You can route the gas line almost anywhere. The splashwell is a good spot.J

 

[soflaguy]

Re: Very high idle when start, then shut down

I was able to find the high idle problem. The butterfly wasn't adjusted in the #2 carb. The screw on the throttle shaft had stripped at one time and I had replaced it with a screw and nut. When I unscrewed both screws to set the throttle arm, I assumed they were loosened and the spring of the butterfly would set them all closed. The middle butterfly wasn't closed. I noticed it when I was starting it and looking down the throat of each carb. Amazing that such a little open would cause such a high throttle. The motor starts easily now. One crank. The rpms seemed too low at 600s. I turned the speed screw in to raise the rpms. I don't think its the way I'm supposed to do that. I'll read some but if anyone cares to chime in. I plan to put it in the water tommorrow and put it in gear. I was doing that for the first time when it started surging because of a carb leaking. I've yet to be able to adjust the idle/air screws. Just wanted to add this so if anybody has the same problem, the little things we take for granted. I had adjusted that throttle arm so many times that I just rushed through it and assumed it was ok. If the intake had been on I wouldn't have seen the butterfly was open slightly.
I understand I must adjust the mixture screws in the water with a load on the exhaust but I can't adjust it in a tank? Must it be in forward gear? If so, I'll try to put it in gear here at home first if only for a second. I know the water will immediately leave the tank. Its just a 42 gal tote. I wish I could find a barrel that would fit the lower leg.
I'm still looking at the water separators. I'm looking on a budget. The one I want is the Racor since you can drain the water so easily but its $78. Perhaps after I've bought another battery and gone a couple of months without another problem. Can anybody tell me what they have or recommend in my circumstance? I need one now.

 

[soflaguy]

Re: Very high idle when start, then shut down

YOWSA!!!!
I took the boat to the water today. Had tool box in hand. Did Frank Acampora's lync and sync this morning beforehand. I had never looked at the butterflies with my throttle WOT and the motor turned off. They were not horizontal. I took the bar off the ball at the tower, opened it up alittle until it would leave those butterflies where they were supposed to be. Snapped it back down and to my surprise, the line at the cam stayed pretty close to where it was supposed to be. I did back off the speed screw on the tower just a bit to put that line closer to the center of the roller but it wasn't exactly like the manual seemed to insist it should be. One thing I read that I hadn't done before was put it in forward gear to 2000 rpms for a bit. I read that this alowed the gas/oil recirculation to begin functioning and the temp to regulate. I also put my thermostat in differently but I placed it to what seemed to me to provide the maximum flow of water up to the thermostat in case I still has something in there that had been causing the alarm to sound earlier. Just kept removing it and running without it, but not underway or in gear.
So I took Jerryjerry's advice and finally cut the umbilical cord and mom's apron strings and let go of the rope that had held me to the dock since 7/4/2010 when I got this boat. I'm telling ya, it wasn't loud, it wasn't skipping, the rpms were exactly where they were supposed to be. I "no waked" outta the little harbor and saw a big expanse of sea before me. The sign read "No wake zone. Boats under 19' with one motor , skiing or similar activity permitted" that meant me. 17',1989 85hp ski boat with 50+ ft yachts along the piers I could see on the other side of the waterway. I did the hole shot! From idle I throttled all the way down and heard the nicest increase in HP and rpms, no misses, surges or hesitation. It went to 38mph, 4800rpms. I had a little more but I'm a big chicken and read too many things on here to not be a little cautious. I spent the next hour just tooling around, opening it up, taking turns at wot and feeling the boat. I never adjusted the idle mixture screws. They are each 1 turn out. I never have checked the timing but it practically purrs (actually surprised its not louder). I'm not gloating here. But I don't want to run too lean or something. This forum really helped me with everything. The manual is a must but there's nothing like somebody whose had the same problems and the group-think that solves them. Thanks

 

[jason32038]

Re: Very high idle when start, then shut down

I'd be careful with those mixture screw only out 1 turn...I disassembled my 86' 85hp engine a few weeks ago and checked my mixture screws and they were 1 1/2 turns out and the engine was stock (no overbore). If you put your thermostat in backward it will not function properly...yes it will still open slightly from the water pressure but there's no purpose to put any thermostat in at all if you're going to put it in backwards because you are eliminating the purpose of a thermostat lol. If the wax side is in the cooling passage of the head (backward) you could possibly overheat while the engine is warming up due to restriction of water unless you get lucky enough that the wax melts before that happens. Risky business.

 

[soflaguy]

Re: Very high idle when start, then shut down

Jason, I'm not sure which side of the thermostat the was pellet is on. Actually, the thermostat is in the way the manual says it should be in. The pointed end is toward the block with the spring area on the outside. My original configuration had it the opposite way and because of the housing, it had a big spring that you put in the housing area to push against the thermostat to hold it flush against the block. I hope you understand this description. Seems US Marine went crazy with springs when they got the Force. Spring in my fuel diaphram and spring in my thermostat. When I was using the thermostat as it was original, I kept having the alarm go off. I attributed it to the mulch I found in there. I have a great deal of water pumping out of the holes and the exhaust. But I also have kept feeling the head with my hand. So far so good. Funny though, I got an old microfiche from US Marine. It is the build sheet of the motor and it shows the thermostat in there backwards with the spring. I did read a post on this forum about some running without a thermostat at all. Do you think I should turn my mixture screws out 1 1/4?

 

[jason32038]

Re: Very high idle when start, then shut down

Yes I would go atleast 1 1/4.