Outboard Motor Reliability

[Master Oil Racing Team]

When I was going through photos this weekend, particularly the series of photos I posted of Jerry Simison, I was wondering about reliability of motors in the other outboard categories. Jerry's motors usually didn't quit in a heat, but it happens to the best in Pro racing often enough. I have only been around PRO and OPC racing for the most part. The only time I watched stocks was in conjuction with Pro racing in Florida and the west coast.

In Pro it's common to stick pistons, disentigrate crank bearings, break belts, shuck lower unit gears, have something shake loose, loose lower units, shear pins, break props, lose exhaust stacks, develope water leaks, carb floats pop loose, etc. Generally, anything that can happen will happen.

I figure the mods might have the same types of problems as Pro, but how well to stocks stand up? In any number of Pro races, sometimes they never even leave the pits, and often they don't make the start or break down during the race. Sometimes attrition is high. I never saw attrition as high in the OPC races I went to, but what about stocks and mods? What were some of the problems other outboard categories experienced while under way? I'm not talking about being hosed down and sitting out the race that way, but total or partial engine failure. There are quite a few members who have run in most or all of these categories. What do you think?

[Skoontz]

Wayne:

great topic as always.

As you may have read back, we have had our share of issues in J class, the biggest not being able to plane, and scattering an engine trying to plane.

The biggest issue there we learned was the boat, not the motor. Other than the time the carb was filled with chitterlings and gravy from dumping in the ocean, the OMC motor was always reliable. We had a fuel line leak and the motor hood blew off during the 2 minute gun least season, but the motor ran good. Same as the AXS Merc, we are in the working the kinks out stages, but, yank the rope, and it is off and running.

[A/B Speedliner]

We started racing in the mid 1950's with a new 20H. We had a few problems but I think that was just part of the learning curve. We did not have a mentor for the most part. Nick Chapman did get us started and help when we went to marathons but the close course racing we had to learn by trying. I think most of our problems were with the engine after it was dumped a few time. But all in all if proper maintenace was done after every race and at the end of the season the engines in the stock classes were more reliable then our mod engines. In the mid 60's when the 20H and the KG4's were starting to get tired and we also learned to push the envelope in tuning the consistent reliability decreased but the speeds went up.

Overall I would say the stock engines, that indeed were stock, were more reliable then modified engines.

Visit our web site to see some of the old engines at aeroliner-boats.com

David

[mercguy]

hands down the 80/102/202/302 Yamatos are the most reliable outboards in boat racing!!!!!!

Yamato 302 motors in STOCK and MOD............add gas, pull the rope and go racing all year long, without any failures....as long as they are not jacked up to high on the transom and pump water (big problem for light drivers)........these motors will withstand a TON of abuse!

Tohatsu in STOCK: damn reliable motor! After having the crank pins welded, I have not had any problems with the motor in over 1 1/2yrs and is still running strong the second season..

Evinrude 45 motors in OPC are damn reliable also...........might have an occassional power pack failure........

key suggestions on all motors though............make sure no water is left in the powerheads after running and change the gear oil after EVERY race day..........and recheck all nuts and bolts for tightness.........AND use HIGH quality 2cycle oil and gas.......

PS: if people would MAINTAIN their equipment for often, it would last a LOT longer! I can't believe some of the stuff I see weekend after weekend on peoples motors and boats............

old ratty fuel lines, rusted up nuts and bolts, grease and oil dripping all over the place, old nasty spark plugs, leaking water jackets, etc, etc, etc...............if people would spend just ONE day (when they are not racing) giving some love and care to their motors, they might just last a little bit longer.............instead of just stuffing it into their trailer after the race and not messing with it until it is put back on the boat for the next race.............our motors need love too!!!!!!

[Mark75H]

Without a doubt the Yamato stock motors are the most reliable motors ever raced. Prime the carb, pull the string and race ... heat after heat, season after season.

Wayne, the new Rossi and Arens PRO motors are infinitely more reliable than the Loopers, Konigs and Yamato PRO motors you were around. High attrition is uncommon and fun is likely. The current motors are so highly refined out of the box there hasn't been a need to improve the motors the way Zak and others did decades ago. Unpack, mount on boat and race ... competitively.


As far as motor failures in Mod ... I've had just about every kind of failure there is: ignition (from bad modules, bad bearings, loose connections, bad insulation, dead batteries) fuel (stuck floats - both up and down, bad pumps, bad hoses, tanks that collected condensation) holes in pistons, broken reeds, broken shear pins, broken gears, broken prop shaft, pipes falling off ...

[Gstillwill]

After running the Merc 15's for five years I never missed a heat or not finish one except when the boat was upside down. The Hotrod has only given ing issues and missed a few heats with that and only not finished one heat in four years. The AMOD Merc which I dont run to often anymore has never broken down and never not started to get out.

[capnzee]

The Parker 300 Enduro is a test of reliability! For the last three years we have "worked" the handicaps in an effort to get an inboard to the podium! We even start some of the faster inboards (GN class) ahead of the Div.III outboards and the "unlimited" (Div. V) inboards ahead of the outboards (Div VI), not to mention the jets who we start first, in an attempt to get an inboard to the podium. Why do we do this? A lot of the spectators want to see all the chrome and are impressed with the noise of the "huffers" and the big cubic inches, they just can't finish! Black Outboards are extremely reliable, big or small! and of the Black motors, I don't think you can find a more reliable motor than the 2.0 Mercs

[David Mason]

In Modified Outboard racing you don't see as many equipment failures as you did in your Pro days. We don't turn near as many RPM's as the Pro engines do either, so that is a factor to consider in attrition. What we do have in Mod is a little more torque on low end and not much mid range in comparrison to the Pro engines of today. That is my experience in running both.

In our years of racing I find that perhaps 80% - 90% of failures on the race course is a result of human intervention. Such as jacking the engine up to high it does not pump water, over revving the engine casuing a failure, improper set up on the boat casuing water to enter the carb while undeway, etc, etc, etc.

It varies from class to class on attrition as well. As some have mentioned, the Yamato engines are pretty much maintence free and will keep on going, just check the timing often (each race) and keep it oiled. The Mod version of the C class Yamato is simply the stocker with a pipe. So the reliablilty is still there. If you cook a yamato it is usually your own fault.

As for the Merc classes we have these are pretty reliable as well. Typically a failure is someone not having the carb set right, or not having the Mag in proper working order. The Mag is the worst part on these engines as far as failure. Switch it over to CDI and you solve that problem.

In the 850CC class the OMC versions of the 49.9CI are extremly reliable. You will break more gearboxs because the powerhead is heavy and provides a lot of torque. It actually slams the driveshaft into the gearbox while underway. Even highly modifed versions of the powerheads are pretty reliable. Stock ignition is bullet proof, cheap and available. Stock exhaust can be massaged to flow better, you can dang near duplicate the racing exhausts that are hard to find with them. The weakest link in this class is gearbox, in my opinion. I have seen powerplants burn up, but it is usually due to condiitons provided by their owners. I have blown mine up at times because I pushed the envelope of modifications. Not the engines fault.

In terms of attrtition I would rate them in order of Stock, Mod and Pro as stock is the most reliable.