'02 90 hp triple sneezing

[Texasmark]

Ok you guys in the know.

I have a real tongue twister. What causes sneezing in recent technology loop charged triple with triple carbs engines that is temperature related? Occurs on muffs at idle and slightly higher rpms. The last time I had the boat out in Feb, '12 it was a stellar performance even after I had replaced a lot of the plastic interconnects on the carb/timing linkage in addition to replacing my fuel line and filter due to floating crud from it....over 10 years old, OEM gray.

Fuel? I live in N. Texas away from the coast and keep my boat in my shop with concrete floor and void of water/condensation pretty much. I always have SF in my fuel at the rate of 1 oz per gallon as specified or more. The last time I ran my boat was in Feb, '12. I buy fuel from a busy station, close to where I boat and buy the grade that has the most worn out selector button (87) which should attest to it's freshness. Station is Exxon. I use Pennzoil premium plus syn. blend oil at 50:1.

Went out yesterday, stellar day, wind <5 mph, temp in the 70's with about 5 gal of fuel/SF from Feb, and added 5 gallons of fresh with 1-2 oz per gallon of SF added plus oil pre mix. I keep my boat in tip top shape.

On the water, the startup was fine and all till out to the buoys for the hole shot which set the tune for the day. Performance sucked. Tried everything that I could on the water with no tools, instruments and all. The guy would not come up to WOT rpms regardless of what I did and made some really funny metallic noises. We were out for over an hour.

In short, after getting home and doing some TS with instruments and all today, I have this sneeze that occurs randomly after 4-5 minutes of operation on the muffs whereby the engine just about dies, big puff of smoke out of the exhaust and repeats.

I put the timing light on the HV leads to the plugs and had a hot spark on all cylinders....light would pickup well before I even got the sensor around the plug wire. All cylds seemed fine. Today at home on the muffs, I swapped CDI's and then with one disconnected (input signal wires) to see if I could stop the sneeze and no results. Basically went through each cylinder by swapping pairs (kept 2 running and would swap the 3rd one) and CDI's.

I ohmed out the yellow stator wires and the green/white and white/green wires from the stator and all were within spec. I didn't do the DVA test as the timing light results were so impressive.

At idle, tweaking the low speed set screws on the carbs did nothing.

Compression check was right at 118 and all cyls were so close I couldn't tell the difference. Used 3 gauges to check for accuracy.

Changed plugs from ones use on the water and same thing; surface gap OEM recommended.

When I goose it, on the muffs, rpms respond immediately to over 5k, rummm, rummm.

I am really stumped guys. Any ideas, and I apologize for the length of this but I wanted you to have some up front info to help us to go from here.

Sometimes you (one) just have (has) to suck it up. You can't help others all the time and this is my time for some help.

Thanks

Mark

 

[Maxz695]

Re: '02 90 hp triple sneezing

I,m having a bad carb day too. They where fine when dismantled poped in some new rings put it all together and went to start it. No fire #3 switchbox quit on #3 polls (third Switchbox on the way ( first got killed by wires hitting the flywheel second unknown) used an old switchbox for #3 and got fire started it up and then the dang carbs that where tip top when dismanteled F ed up. Tried all day with no resolve other than idol and a bit more. Think it,s the weather or left over Demons from holloween? After my affair and the likely hood of all new carb patrs or even a set of used carbs I don,t dare give advise on your situation It,s been one of them days

 

[Texasmark]

Re: '02 90 hp triple sneezing

I,m having a bad carb day too. They where fine when dismantled poped in some new rings put it all together and went to start it. No fire #3 switchbox quit on #3 polls (third Switchbox on the way ( first got killed by wires hitting the flywheel second unknown) used an old switchbox for #3 and got fire started it up and then the dang carbs that where tip top when dismanteled F ed up. Tried all day with no resolve other than idol and a bit more. Think it,s the weather or left over Demons from holloween? After my affair and the likely hood of all new carb patrs or even a set of used carbs I don,t dare give advise on your situation It,s been one of them days

My experience with sneezing was with 2 cylinder OMC primarily rental boat fishing motors back in the '50's and 60's. Seemed it was a problem with lean mixture. Back then you had the mechanical ignition without all the current whistles and bells and it either worked or you paddled home....no trolling motors back then.

I don't have my manual here in the house but the term switch box sparks my curiosity. I'd have to look at my wiring diagram to see what I have. I know I don't have a rev limiter on this engine.

For the engine to idle perfectly for a couple of minutes or whatever time it is, just to sneeze, cough, belch, or pfart....whatever you choose to call it, for one occurrence then clear the smoke out and repeat the process....smells of lean mixture of the old days. However the lean mixture back then was continuous; sneezing was every rpm until you put a load on the engine and then it would settle down....put the thing in gear in the water on the boat and it would quit. As I said I tweaked the carbs and rotated cylinders and it remained.

I am dumbfounded. In time some of the big guns will hopefully jump on this and bail us out.

Thanks,
Mark

 

[Maxz695]

Re: '02 90 hp triple sneezing

The only thing that comes to mind is temp drop and rubber cracking be it neeldles and seats fuel line poly filled companants etc. I hope int isn,t serious for you I,m at the end of my rope with little hair left and a 12 gauge. I,m no quiter but my wallet is screaming at me not to mention the ol lady. I can,t believe Ive done all this work to have componant failure at this point in time.

 

[aussieflash]

Re: '02 90 hp triple sneezing

Could it be a bad reed causing sneezing?Maybe a snapped metal petal could be causing that funny metallic noise.I hope im wrong.

 

[ENSIGN]

Re: '02 90 hp triple sneezing

Since you had a problem with the gray fuel line the little bits and pieces will get stuck under the check valves inside the fuel pump and cause a lean sneeze.

 

[Texasmark]

Re: '02 90 hp triple sneezing

Could it be a bad reed causing sneezing?Maybe a snapped metal petal could be causing that funny metallic noise.I hope im wrong.

Possibility. I did look thru the venturi's at them but the pedal shaped reed doesn't allow you to see much of the actual reed. Once I got the engine back home and on the muffs it was perfectly quiet. I had the plugs out rotating it by hand and it was as smooth as silk. If I decide to jerk the carbs I'll give them a good going over.

Funny, while on the water and acting up it didn't have a constant pattern. It'd do one thing for awhile and then something else.

One thing I did notice that I may not have mentioned was that #3 plug was cool as compared to the other two at the metallic base and #2 was the hottest of all. With that I assumed that #3 CDI was failing. But when I got home and on the muffs, I put the laser thermometer on them and they were all within about 10 degrees of each other and the flashes off the timing light all looked alike. That I found really confusing.

Since this problem is so peculiar and elusive, I am going to nail it down (if I can) before I start just throwing money at this.

Thanks.

Mark

 

[Maxz695]

Re: '02 90 hp triple sneezing

It may be possible that the old fuel may have settled and separated causing the oil gas ratio to be more oil than gas (Big puffs of smoke) and fouling the plugs. 3 New plugs would tell the tale there. Small amounts of water intrusion will make the engine sneeze consistantly mostly noticable at lower RPM,s after being run for a short period of time and the warm up. My 40 HP when I was just starting out 2 years ago would do that It would start fine get out run great but when coming back in it would sneeze. I tryed adjusting the carbs but no change. The cause was a corroded divider plate which I replaced and it was fine after that. Damage I later found out did occur to the crankshaft and bearings and I later replaced the crankshaft and it worked fine. Poorly seated reeds will cause the intake to be off from it,s required carburation and might also affect the mixture screws when trying to adjust the carbs spitting or backfiring through the carbs. The thing is you heard metal clinking around in the engine which is never a good thing. <Edit> The damage done to the crankshaft was a combination of the water intrusion that came on slight at frist to more frequently as I continued to use the engine and major over reving due to cavitation when turning my 17 and a half foot boat with the small engine. Ive scince bought the 70 HP powerhead and it ran fine the first time I took it out but when trying to do some maintanace on the engine I bought noticed the #3 piston was in a bad corroded state.Thats when the Sht hit the fan here

 

[CharlieB]

Re: '02 90 hp triple sneezing

Carb cleaning should cure it, pay particular attention to ensuring all floats are set the same. I know that you know how to properly adjust idle mixture.

Carb sync is absolutely critical to maintaining even temps on all cyls, a hot cyl is often cause by that carb being ever so slightly open and trying to accelerate, 'leading' the motor while the cold cyl carb is farther closed and 'lagging' and thus running cooler.

Many many moons ago I threw away the book and started adjusting the throttle racks on the old Detroit Diesels, sync'ing cyl injectors by exhaust temps, made a whole different motor, they ran smooth and had far less intake wetness as no more 'lagging' cyls.

 

[Maxz695]

Re: '02 90 hp triple sneezing

Turns out my inboard fuel tank and the fittings 3/8ths and primer bulb also 3/8ths where the victim of ETENOL/ I used my mix tank (6 Gal) with 5/16ths hose and the engine ran and ran and ran and kept on running tearing the tank out to inspect the pick up and replacing the 3/8th hose with 5/16ths hose and never using ethenol gas again Texaco is a few blocks further and well worth the effort to get NON ETHENOL GAS!!. (Unless i,m stuck on the water even then the 5/16ths is i much tighter fit. I can move on now.

 

[Texasmark]

Re: '02 90 hp triple sneezing

Carb cleaning should cure it, pay particular attention to ensuring all floats are set the same. I know that you know how to properly adjust idle mixture.

Carb sync is absolutely critical to maintaining even temps on all cyls, a hot cyl is often cause by that carb being ever so slightly open and trying to accelerate, 'leading' the motor while the cold cyl carb is farther closed and 'lagging' and thus running cooler.

Many many moons ago I threw away the book and started adjusting the throttle racks on the old Detroit Diesels, sync'ing cyl injectors by exhaust temps, made a whole different motor, they ran smooth and had far less intake wetness as no more 'lagging' cyls.

Carb sync: Sounds like a potential culprit. I didn't think about that as a possible cause but it makes sense and making sense is how I look at life and everything about it. I have the Seloc and OEM manuals and I am starting from scratch on the carb/linkage adjustment. I wish I had a test prop and a test tank so that I could work on this thing at home. Having to "hope I got it right" and driving 30 miles to find out that I did or didn't isn't very pleasant.

If the current adjustment procedure doesn't fix it I am going to get some kits, pull the carbs and clean them up as you suggest and while there check the reeds as Max suggested.

One thing I did notice was that the ss carb interconnect arm doesn't move the butterflies evenly. If I set up the carbs such that the BFs are fully closed at idle, at WOT the top one is not as open as the other two. If I try to correct that the top one for WOT positioning it has a slight gap at idle and the engine won't remain at a constant rpm. I don't care any more about seeing what the rig can do. I know that and now I am more interested in cruising around. So at WOT if one isn't quite carrying it's load I guess I won't worry about it.

I Really I have no choice. There is nothing worn in the carb interconnect linkage including the carb parts and therefore nothing to replace. Engine doesn't have all that many hours on it. On the rest of the linkage, not too long ago I replaced all the little plastic swivel receptacles where the interconnect SS rods connect and the plastic cam that operates the carb linkage. It's as tight as it looks like it is going to get but still at WOT where max linkage pressure is exerted there is a little slop between the throttle cable attachment point and the roller on the carb linkage which includes all the moving parts between these two points.

Thanks for kicking in.

Mark

 

[Texasmark]

Re: '02 90 hp triple sneezing

It may be possible that the old fuel may have settled and separated causing the oil gas ratio to be more oil than gas (Big puffs of smoke) and fouling the plugs. 3 New plugs would tell the tale there. Small amounts of water intrusion will make the engine sneeze consistantly mostly noticable at lower RPM,s after being run for a short period of time and the warm up. My 40 HP when I was just starting out 2 years ago would do that It would start fine get out run great but when coming back in it would sneeze. I tryed adjusting the carbs but no change. The cause was a corroded divider plate which I replaced and it was fine after that. Damage I later found out did occur to the crankshaft and bearings and I later replaced the crankshaft and it worked fine. Poorly seated reeds will cause the intake to be off from it,s required carburation and might also affect the mixture screws when trying to adjust the carbs spitting or backfiring through the carbs. The thing is you heard metal clinking around in the engine which is never a good thing. <Edit> The damage done to the crankshaft was a combination of the water intrusion that came on slight at frist to more frequently as I continued to use the engine and major over reving due to cavitation when turning my 17 and a half foot boat with the small engine. Ive scince bought the 70 HP powerhead and it ran fine the first time I took it out but when trying to do some maintanace on the engine I bought noticed the #3 piston was in a bad corroded state.Thats when the Sht hit the fan here

Water in the fuel is an interesting thought. I have a plastic BI tank also. As I said, it has been at least 6 months since I ran the boat and I had premix and about 1 oz per gallon of Sea Foam. The tank is vented. I keep in in my shop which is really a bland environment when you think about weather affecting moisture in the tank. Phase separation is surely a possibility. I did run the engine on muffs the day before I went out and it ran fine, initially with some intermittent sneezing but I opened the top low speed jet 1/8 turn and it quit. I ran it 15 minutes or so after that and it didn't sneeze once.

On the way to the lake I stopped off and got 5 gal of gas on top of the 5 gal of old gas and did my premix and added more SF, actually about 2 oz per gallon this time. What I may do is do the carb/linkage adjustment and if that doesn't fix it, drain the tank and put in fresh analyzing the old gas that I take out. If that doesn't work do what I told Charlie I'd do which includes having a look at the reeds.

When you have the engine hitting on all 3 nice and smooth at idle and all of a sudden the engine just dies for an instant and upon recovering you have this big blob of smoke out the exhaust really makes you wonder how the engine could do that to itself. If regularly occurring, every revolution it would make sense, but once every couple of minutes?????

Fuel well could be the culprit as fuel goes to all the cylinders and if a water droplet came down the pike so to speak, it could make the engine balk. Buttt the fuel comes from the bowl of each carb and for that to happen to all cylinders simultaneously is doubtful.

Thanks for kicking in,
Mark

 

[CharlieB]

Re: '02 90 hp triple sneezing

If one carb has been replaced the distance from the throttle shaft to the linkage attachment may be different from the other carbs. This may account for the difference in the rate of throttle opening/closing.

If this is the case then adjustment should still be done with all carbs fully closed as low speed throttle control is critical to safe docking.

Eventually replacement with the correct carb is advised as it would make a difference in WOT RPM and power.

Check the #'s on each carb, compare to Merc Parts and post here. Some of these guys know a lot about carb casting #'s.

 

[Texasmark]

Re: '02 90 hp triple sneezing

If one carb has been replaced the distance from the throttle shaft to the linkage attachment may be different from the other carbs. This may account for the difference in the rate of throttle opening/closing.

If this is the case then adjustment should still be done with all carbs fully closed as low speed throttle control is critical to safe docking.

Eventually replacement with the correct carb is advised as it would make a difference in WOT RPM and power.

Check the #'s on each carb, compare to Merc Parts and post here. Some of these guys know a lot about carb casting #'s.

I doubt that is the case. I bought the boat at 2 years old and there are no marks indicating any wrenches on that part of the engine. All the carbs have the same numbers. I thought about ordering kits, but having problems. I posted a new thread today to that accord. What's funny is that there is a WVE on the side of the carb but right in the top in bold letters is 2B2.

Thanks,
Mark

 

[Maxz695]

Re: '02 90 hp triple sneezing

If you have had this engine for some time and the problem is a new recent issue I would rule out miss match carbs

 

[Texasmark]

Re: '02 90 hp triple sneezing

Today I tore into it and found the main smoking gun. Hopefully this will help someone.

My last time out as I said #3 was apparently the one loafing as the plug metallic base was cool to the touch when the others were much hotter. Since I couldn't get over 4k rpm when I could easily run 5.6k with the same load something was obviously wrong. I then said that once I got back home and on the muffs all three were running about 138F.

I pulled the carbs off today and there was no varnish even though these carbs haven't been touched since new in 2002 (no wrench marks on any associated bolts). I have had this boat since 2 years old and have kept Sea Foam in the fuel. Nowadays I only get out about every 6 months but even with that all the parts were immaculate.......however this is a triple and has 3 carbs and upon removing the bowl on the lower carb (#3) I blasted it with Berryman's Chem Tool and compressed air like the others and just by chance this plug of crud came out of the high speed jet. It wasn't varnish, it was oil and dirt.

My assumption is that over the years, the filter filters down to 10 microns or whatever, but particles smaller than that pass through and over the 12 year life of this engine accumulated in the lower carb.

So, the crud apparently is the reason I had the WOT problem. The interesting thing is that when I got home and put it on the muffs and the plug temps were all uniform, I failed to know/realize that on the muffs you run at idle. Well sports fans, idle rpm fuel comes from the idle circuit so it didn't matter that the #3 high speed jet was clogged as I wasn't using it.

Currently I am not worried about the sneezing as it doesn't happen on the water; just on muffs where the 2 stroker is unloaded and to me that is part of the beast.

So, in summary, this is my engine and I know the history. I spent most of the day working through it. I think I have the problem solved and will know the next time out....next week and will report.

The thing that I want you, the boating public to realize is that had this been your boat and you took it to your/the local mechanic to fix, he would have had his plate full. Since dealerships have overhead including mechanics wages and benefits, this guy may have spent all day on this peculiar problem, charging the going rate to pay the bills of roughly $100 per hour and he may and may not have figured out the problem. The mechanic usually has no insight into the engine's history and goes on your description, his experience, and what he finds.

So folks, the next time you get your shorts in a not because the mechanic charged you $800 labor for a funny problem like this, give him a break.....or just do it yourself!!!!!

My 2c,
Mark

 

[Texasmark]

Re: '02 90 hp triple sneezing

Well,

So, the repair effort yesterday consisted of taking 2 covers off the carbs, checking the condition of the needles, checking the float positions, spraying a couple of times with Berryman's Chem Tool carb. cleaner and good blasts of compressed air, reinstalling and setting the low speed needles the required turns, reassy of carbs and carbs to the engine, then setting the linkage per the book. While the carbs were off I gave the reeds a good looking over and they seemed to be in spec. That was it. While the fuel line was off the carbs I shot about a pint of fuel mix into a clear container yesterday and this morning it was still uniform and clear; no water and no phase separation.

I put it on the muffs and lit it off this morning. Starting was excellent, none of the pampering I used to have to do to get it started even though the bowls were empty. Set the timing. Everything seemed to be where it should be. Idle was nice and strong, all cylinders hitting, none of the blobs of smoke and sneezing; took the throttle really well. I am ready for the lake test. Since I found the smoking gun attributing to the WOT problem I feel that it will be a stellar event.

Hope this helps someone.

Oh and I didn't realize that this engine is 10 years old and this is the first time the carbs have been into. Yeah Sea Foam!!!!!!! For you disbelievers, fine; your money, your equipment; your possible loss from not using it. Me? Introducing me to the product is probably the best thing I boats has done for me since joining.

Mark

 

[Maxz695]

Re: '02 90 hp triple sneezing

I tottaly agree on the sea foam Hope all goes well Texasmark

 

[Texasmark]

Re: '02 90 hp triple sneezing

I tottaly agree on the sea foam Hope all goes well Texasmark

Thanks. Fixing to head out in a little while and see how things go. Will report back.

Mark

 

[Texasmark]

Re: '02 90 hp triple sneezing

The grand finale. Today was a stellar day. The politicing is over, the day was bright and sunny, the wind was calm, no waves other than the boat wakes 2 other boats and I made on the water and they were fishing, I was playing.

It was a fantastic trip and I touched nothing on the engine. I didn't even adjust the low speed settings from the basic initial settings (the manual says) of 1 1/4 turn for all three. Utterly amazing the difference in the performance of the engine today vs the last outing. Absolutely unbelievable that a little crud blocking the high speed jet on #3, a trace of the same stuff in #1 up on top where all the low speed fuel air is prepared, and getting the throttle linkage adjusted to spec would do to an engine that purred like a kitten today vs the last trip out when it was banging and clanging, wouldn't run over 4k regardless of what you did, belching smoke like a steam engine, and getting the feeling that it was ready for the scrap yard last time out.

I have been running a Ballistic 24XL on this engine and running 5600-5800 WOT with my sweetie and I plus fuel and batteries. I decided to change it out for this time out with a Ballistic 21 I had just to help the engine to flex it's plex (has to do with metropolitan areas referred to as Metroplexes). I am going to open a separate thread when I close this and the title will be rpms and 2 strokes. Look for it.

And the beauty of it is I didn't "throw" one part at it. No parts were replaced.

Mark