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Older Johnson/Evinrude Reliablity
|Author||Topic: Older Johnson/Evinrude Reliablity|
posted 04-09-2004 03:51 AM ET (US)
We have a Evinrude dealer up north in Utah that is showing signs of new life with the E-Techs. I stopped by this last week to look and talk and they had an new mechanic that had moved here. He appears to be very good on outboards which was the reason they brought him in and was very familar with the OMC carbed engines of the 80 and mid 90s that I have.
He made an interesting comment that I would like some opinions on regarding the carbed V-6s OMCs (or any other carb outboard) of the era mentioned. He was from Florida and had worked on thousands of Johnson/s Evinrudes for over 2 decades and had personally seen many with thousands of hours on hour meters. His opinion was this. Those OMC carbed engines were great workhorses and mainly bulletproof except for this one issue. Many of the carbed OMCs of that era never had a chance to wear out the powerhead/pistons/rings from running time alone. Most of the time, a single piston siezed and ruined an engine long before compression figures on all cylinders came down to a non-usable state. The main problem was always a lack of maintaince, especially after long term storage. The owner would start up the engine and wouldlock up a cylinder because a carb was clogged up (jet I am assuming) and run the corrsponding cylinder lean and poof, it was over.
Does that sound right? I constantly see carb outboards for sale with a "bad cylinder" need of repair? Do many of these good ole carb outboards meet their time prematurly because of this reason alone?
If so, other than adding fuel stablizer and fogging cylinders, what else is good to do to prevent this after winter storage. Drain the carbs completely?
It seems an outboard carb owner is flying blind every spring starting up. How would one tell on start up if a cylinder is lean or a jet clogged before the damage is done?
posted 04-09-2004 08:36 AM ET (US)
I agree completely with the wrench you talked with.
The weak spot in all multicylinder, multicarbed 2 strokes is the user who is either not alert to signs of fueling trouble or continues to run an engine that is not performing properly. If one carb throat clogs on a V4 or V6 (even inline triples and twins) the engine will still "sound" okay to the untrained ear; if the user continues to run the engine that cylinder is history.
If enough cylinders fail to make power so that the boat wont plane or wont come off idle they take it to a shop. Often that is too late.
The carbed OMC V4s and V6s are excellent engines when maintained properly, and will last into the 3,000-5,000 hour range without major repairs. I think the same is true of all multicylinder, multicarb engines of any make.
Red sky at night. . .
posted 04-09-2004 03:42 PM ET (US)
Thanks for your reply JB
In our area, most boats are winterized 5 to 6 months a year. With that kind of downtime sitting, what would you suggest above the fuel stablizer and fogging? Is completely emptying the carbs of gas a good idea to prevent clogging/gumming up and what is the best way to do it? Just run the engine dry?
posted 04-09-2004 05:10 PM ET (US)
Only- I also agree with the observations of the wrench and JB. The cross-flow V4 and V6 OMCs were quite reliable as long as they were maintained.
I never ran my Johnson 150 dry before putting it away for winter storage. Just put fuel stabilizer in the fuel tank, ran it through the engine and then fogged the motor. At the end of every season, about 50 to 75 hours or so, I'd have the motor decarbed. That's it. Never had a problem with the carburetors gumming up or leaning out and burning up a cylinder.
Also, some of the best continuing preventive maintenance is having a water separating fuel filter in between the fuel tank and the engine.
posted 04-10-2004 01:22 PM ET (US)
I haven't winterized a boat in some time (no need anymore) but running the carbs dry is one practice I always did. Whether it was my boat engine, snowmobile, lawn mower, motorcycle, etc., I would always do it. Of course, this was in addition to fogging the cylinders and adding stabilizer. Come the next season, the engines would fire the instant fuel got into the cylinders.
As for how to do it, close the fuel petcock if there is one or disconnect the fuel line. Then, let the engine run itself dry. I've never scored a piston or cylinder wall with this procedure either.
posted 04-11-2004 12:47 AM ET (US)
I believe that in the realm of older 2-stroke outboards there is a schism between engines that are "Cross-Flow" and engines that are "Loopers". These are terms which refer to the air/fuel induction into the cylinder.
I also believe that in general the Looper is preferred for its better fuel economy. Are there other advantages to Loopers versus Cross-Flow engines?
In the OMC line, when did this change take place?
posted 04-11-2004 09:44 AM ET (US)
I completed the following on both motors, new parts.
Annually I replace plugs, waterpumps and lower gear oil. Also decarb every 50 hrs while adding decarb fuel additive to the fuel tank. I'll replace thermostats ever 2 years. I also flush them with freshwater after every use. When winterized, I always add fuel stabil and fog the cylinders. I don't drain the carbs. I'll probably have the carbs cleaned every 4-5 years depending on usage, thats still up to bedate.
I think 2 strokes in general need regular maintenance simply because they aren't run regularly. A motor sitting is damaging mainly because carbs/jets fowl and lean out. There are alot of great older 2 stroke motors that just need some basic maintenance, they are reliable too... Prevenitive maintenance is very important to me as I run them 50 miles offshore on Tuna trips.
posted 04-11-2004 11:14 AM ET (US)
Jim, answering your second question first, OMC introduced its first loop charged outboard in an I-3 configuration in 1968. Its two cylinder loop-charged outboard followed in 1970 or 1971. All of its V4 and V6 outboards started out with cross-flow induction. In 1985, OMC introduced its first loop-charged 90 degree V block engines, 120 and 140 HP V4s, 200 and 225 HP V6s, and 250 to 300 HP V8s. In 1991 or 1992, the loop- charged 60 degree V6 in 150 and 175 HP configurations was launched so after that time, all recreational V6s were of the loop-charged variety. I believe the loop-charged 60 degree V4 (90 and 115 HP) came out in 1995.
Having run both cross-flow and loop-charged OMC V6s, it is my observation that the loop-charged motors tend to have a somewhat non-linear power curve. The power curve on the cross-flow V6 seems linear or flat throughout the entire operating range. The 90 degree V6 loop-charged motors usually developed their rated power at higher crankcase speeds than the cross-flow versions.
With respect to reliability, I believe all of the cross-flow V6s used three carburetors while the 90 degree loop-charged V6s and V8s used four carburetors. So it would seem that by having more carburetors and running at higher crankcase speeds, there is a greater chance to have a carburetor related failure on the 90 degree loop-charged V6s than on the cross-flow versions. Nothing scientific here but it has always seemed to me that more often than not, it was the loop-charged 90 degree V6 engines that were blowing power heads rather than the cross-flow engines.
If disconnecting the fuel line to allow the carburetors to drain, make sure that when the line is reconnected that it is very tight. There is an increased risk of an air leak when the fuel line is disconnected and reconnected on the V6s as they do not have a quick connect/disconnect (they don't use these fittings because of the risk of air leaks). An air leak into the fuel system can lead to a lean condition engine failure.
posted 04-12-2004 12:01 PM ET (US)
The looper V6(200 & 225) debuted in 1987 I believe.
Yes he is correct my father put 70 hours on my 225 in 6 years and I stuffed a piston from a lean carb/broken thermostat issue. The VRO still works great. These engines are awesome but they are kinda loud and LOVE fuel.
posted 04-12-2004 12:45 PM ET (US)
No hour meter on my 1985 Johnson 70Hp engine, but it's still running like a champ... Despite being 19 years old... The 1981 70Hp Johnson my dad bought new in 1982 was running strong when he sold it 3 years ago... The 1973 Evinrude 50Hp he had before that, was running strong when he sold it in ~1993. The 50 did throw a connecting rod while we owned it, but amazingly despite the hole in the crank case, it continued to run. The truly amazing thing was the hole was in the same portion of the crankcase the fuel pump used for pressure. (still don't understand how it continued to run).
I remember watching many many times as my dad pulled the carbs off the 50 to clean the crud out of them. Fortunately, this particular engine tended to plug the idle jet and give some warning that it needed it's carbs rebuilt...
I agree with the mechanic...
posted 04-12-2004 12:55 PM ET (US)
Bigs, I had a 1986 225 on my 1986 Revenge 22 so introduction of the V6 looper was at least as early as model year 1986 which would likely have been introduced in the Fall of 1985.
posted 04-12-2004 02:23 PM ET (US)
Could be....if it has a V6 embossed on the back of the block about 2" tall between the heads, she is a looper, same with V4 & V8. I assume they figured with the 2 & 3cyl people could count the cyls.
posted 04-15-2004 08:56 AM ET (US)
everytime I read about these old "carbed" engines it amazes me just how far we come with the technology. EFI, HPDI,E-TEC, Optimax...etc.
And some now look down on the carbed loopers that got us here.....if it wasnt for peer pressure, I would still own one....
posted 04-15-2004 11:17 AM ET (US)
OLD? Evinrude in 1997 only HAD carbed engines. This technology is so new it is scary but yet it seems to be working out well. I still own my 94 carbed Johnson which in 1994 was the "woo" except for a few EFI engines that commanded a much higher pricetag.
posted 04-16-2004 11:14 PM ET (US)
I have a '78 Johnson 70hp on the 15' Sport. I've had the boat since 95. Had the carbs rebuilt twice,once when I bought the boat and once when I was having a problem with a power pack. It's had regular maintenance with moderate use. Last summer the compression was at 150psi on each cylinder. Not bad for an antique. No real problems with skiers etc. It still has a lot of life in it.
posted 04-17-2004 05:42 PM ET (US)
Questions for the OMC experts, forgive my lack of knowledge. I have an Evenrude V6 200, model # E200TXENE that I am guessing was purchased in 1992. Only has 140 hours on it, I am powering a 1983 V-22 Revenge. Motor only used in salt water. I am positive the motor has been tuned and winterized a few times but that is all I know. Just got back from the first trip this year. The motor ran great. Got 9 gph at 3500 RPM. Boat will plane at 3200, seems to do a better cruise at 3500. WOT was 5500. Do not know speed, no GPS just a funcky old water pressure actvated speedometer that you have to tap on in order for it to move. Have to watch the trim due to changing water conditions. Smooth water on the way out. Could trim quite high. A bit rougher today on the way back in, had to run with the engine more down in the water. Three hour round trip. Questions, is 9 gph sound about right for that engine/boat/rpm combo? How do you "de-carb". I looked at the additives at the part house and was overwhelmed by all the differnt type of injector, carb cleaners to add to your gas. What should I use or would you recommend I have a professional clean the carbs? Thanks
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