I had fun this summer with the Sea Lark on Pigeon Lake in Alberta Canada.We put the boat in the water for the first time in July. Still working on a few problems such as left hand torque steer from the Evinrude 100s with seemingly no adjustment for this.
Hello Bill, so far the motor speed wise is a big disappointment. Seemingly I made a mistake, I only went through the motor elastically as I was assured it was all tuned up and running strong. I am only getting about 35 Mph out of it. It runs well and idles well but just doesn't make the top end power or RPM needed. Right away I had to replace the fuel pump diaphragm ( this was my first clue) , it has good compression so I imagine it just needs the points done , timing set and go through the large single carb. I plan on going through it this winter and figuring it out. I have tried 3 different props but that is not the problem. Typical, I shouldn't have trusted others... The other thing I don't know about is how to get rid of the left torque steer from the motor. it doesn't have any adjustable fin like a Mercury has to off set the prop torque?? Thoughts ?? Brad
That rig is simply stunning and very WOW! I am going back now for another look. Good luck from the OMC people to work out your details. (I trusted a previous owner who said everything was good except reverse...turned out a scored piston as well...lesson learned to bring a compression gauge next time...I would have said maybe he didn't know, but my mechanic said the motor was taken apart and put back together knowing it was bad). Hope yours is simple details. Such a great boat to still see saved and running!!
Nicely done! The OMC's were not really known for speed since they were always stomped by Mercs even back in the early 50's (as far back as I can remember) Sure is nice to see those old girls back on the water where they belong.
Interesting the dash in the sales picture has the steering on the other side than mine, thanks for your comments and the sales picture . I think the 100s Evinrude should at least push this boat up to mid 40's, I'm 10mph away from that. Time will tell after I go through the points, timing and carb. One would think 100 hp would make for lots of power on a small boat like the Sea Lark.. Brad
Check your fuel fittings too. Are you holding prime ? What a difference a leak you cannot see will make. I learned the hard way. That's truly a work of art and I've never seen or even heard of one before. Beautiful boat and nicely done !
Excellent Brad she looks awesome!!!!!!!! Yep the larger JohnnyRudes like 50hp and up all torques steered that I recall. My '59 50hp Golden Jubilee did big time. The '67 80hp I have now does also, though not quite as bad. To make up for it I adjusted the cable steering to compensate since most of my time is not at idle speeds.
Makes good sense your point about a small fuel leak, it could such air. I already replaced the fuel pump diaphragm , I am sure it holds prime pressure but I will double check!!
Bill also showed me a wedge shaped piece of aluminum on EBay that is sold to fix the prop torque. It bolts to the lower fin of the motor and adds some right turn to negate the left pull. It is a long wedge shape, I believe you add more or less length of it to give more or less counter steer for your torque pull. I have ordered one and will see how it works. Can't see that it won't solve the problem.
That sounds like it might work. Do not try those blasted whale tails things. I did and it was ridiculous how badly it impeded the boats performance. It wasn't a rocket to begin with but I could barely plane with those on !.
Yes I agree those things as well as ugly aren't much good. I am surprised the Evinrude 100s doesn't have a adjustable fin like Mercury used to off set the torque steer. The engineers must have felt the problem while testing their motors. It doesn't take a rocket scientist to figure out there is a problem and a fix for it at the factory level ????
I did in 1983 on a 200 merc v-6 on a 17'9" Hydrostream Viking with a hydraulic lift transom. I ran a bow lifting chopper prop (cleaver would have been better) ... anyway, it worked for me, but I was running high speed with partial blade out of water. My 87 200 merc on a 20' Hydrostream VoyagerXT has it built in as part of the lower skeg casting. I don't have an adjustable transom, it seemed to work better when mounted higher. I had to lower motor for better skiing. Being lower and slower speeds don't seem to relieve Torque as well at slower speeds. I am thinking because it doesn't produce the same water pressure at slow speed as at high speed. Perhaps each hp would react differently. That is just my experience. I could not run the adjustable Torque tab due to prop blade sticking back so far it would hit. Hope others chime in with rigs closer to what you have. Good luck. I know my neck hurt from the Torque after 5-6 hours of pulling skiers. If I could have afforded hydraulic steering, then that would have made things much better.
I have a 1966 100HP Johnson Golden Meteor and I also get about 36 to 38MPH on my 1963 Aristofcraft Funliner. Ironically enough the 13 x14 prop makes the boat much more responsive and fun to drive then the speed prop of 12 1/2 x 18.
Someone did say that even though mine is 100HP, could have loss a bit of it's power given how old it is. Also, all my compression is at 105 to 107 on each cylinder.
I have also switched my steering to uflex and it drives like a dream, however, there is still significant torque steering going on.
Interesting to hear, not what I want to hear but interesting to see other experiences with a similar motor. I just got the Evinrude factory manual off of Ebay. Its a great simple to understand manual that shows all the tune up and low power trouble shooting. I will go through it all this winter checking the points, timing, reeds, carbs etc...Brad
Yes, just one perspective. I'm not a mechanic and all the work I have done myself. The only thing I really think that I still need to do is to rebuild the carbs, but for this model that seems to complex for me to handle and where i live, we don't really have people that could take it on for that age of motor.
Your motor sounds good, any idea what you were getting for speed? Mine sounds similar but maybe not as high an RPM as yours I was surprised when I was only doing 34-35mph by GPS on my phone. Speed on water is tough to judge. I have 4 different props for my motor, I tried the 2 I thought would be the best with the same results in the top end. I am pretty sure either my timing is not correct or the exhaust ports are carbon-ed up. The manual says that is a common problem with them
I think that day it was about 36 or 37. My boat only ways about 600lbs, plus the motor, gear and the two of us in the boat. My RPM's were at 5200 that day which was the highest I had ever gotten. I had the 13 x 14 prop on that day.
As for the 100S, experience tell me you should be able to get 40mph plus out of it, but I don't know how heavy your boat is. Also, is the transom 15, or 20 inches? The wake of the boat looks really minimal, so I'm assuming that the motor is the correct length. If it's a short 100, with the large 100 HP gear case, you lucked out. Those are hard to come by.
If it is the correct 100 gear case, you are needing a 2 blade Michigan cupped prop for it.
These motors are torque makers, and they don't like to rev like Merc engines. The exhaust ports are small, and they build power better between 4k and 5k RPM.
The carb kit is extremely expensive if you can find one , and is no longer produced by anyone. The carb should not be disassembled unless absolutely necessary.
But I think some tweaking will get more out of it.
As for the torque steer, I put a Teleflex no feedback helm ( Teleflex NFB Rotary II ) on my Reienll to solve that issue. I had a metal shop fabricate an adapter bracket, so the original bezel and wheel were retained. The Reinell uses a Nautalloy wheel - just as your Sea Lark does. I had to cut about 3/4" off the height of the chrome bezel for the helm - but the results were great & nobody can tell the boat has a modern NFB steering system, unless they look under the dash.
My Reinell could reach 40MPH with a perfectly set up 75 HP, and I have driven 2 Glasspar G3s with Evinrude 75s that could reach 38-40 mph on a good day. On a light boat like yours, the motor will launch from stopped to full speed in just a few seconds - like under 10 seconds. But the motor will hit a brick wall if the RPMs are too high - shoot for a top RPM of 4,500 to 5,00 tops.
Hello, thanks for your comments, the motor is a long shaft and the boat has a 20" transom . I was lucky enough to get a carb kit off of ebay as well as 4 different Brand new Evinrude props of various sizes all listed for the motor a few years ago. Currently the motor starts well, idles well, goes into gear well with no sign of stalling but is really doggy our of the hole struggling to get the boat up on plane, I thought maybe I had over propped it but not the case as it did the same with less pitch. The boat only weighs about 600lbs with out the motor and I have the tank in the front since you sit so far back. After running it for quite a while I pulled the plugs and did another compression test , they were all the same and about 115psi. Here is the weird part, one plug looked nice sandy brown color, 3 plugs looked new, no build up of any kind like the one other plug, I wasn't sure if they were fuel washed or super lean? That's why I thought I should go through the carbs checking the reeds while I am in there. The motor had a good sound running and to me sounds like it is on all 4 cylinders but just doesn't make good power. I am a licensed mechanic but two strokers are still a learning curve for me.
Erik is a big believer in his ultrasound cleaner for carbs,,he has cleaned ran it then come back put them in ultrasound and does better job,,if you can get your hands on one might help,boat looks lioke it is riding right on plane,I have found big difference in long and short shafts but still should come out of hole,,this one pegs the speedo,running 19,s at 5200rpm and that is enough for this,16ft AMERICAN MARC,TWIN 135 SHORTYS FROM FRANKENMERC, Bill
What brand of plug are you running? I've never had any good results with Champion so I like to install NGKs. Are the plugs normal tip or surface gap? If three of the plugs are super clean like brand new it might indicate some small amount of moisture getting into the cylinder(s). Pull the plugs and take a flashlight to peek into the holes and see if there is any buildup on the piston heads. A little dark is normal, clean/new is suspicious. Maybe just run a tank of SeaFoam to clean things up.
I am using the recommended Champion J4J plugs , regular tip type not the surface fire type. I am running SeaFoam in my fuel now since I started the motor. I guess it wouldn't hurt to try a set of NGK's . Thanks for your thoughts
I just deleted my response after viewing your videos of the boat. The engine sounds good, and the RPM's sound about right for top end. But the boat sure isn't winning any speed records.
I'm guessing that the boat has extremely low hull efficiency, and that is why the speed is lackluster. That's only a guess, but beyond that, I'm short on ideas. If you are running OMC 3 blade props - you need to find a vintage performance prop from Michigan, or OJ. The factory OMC props have zero blade rake. A good Bronze prop with some rake angle will help.
Have you tried maxing out the tilt angle?
Removing the burgee when you are trying for top speed will also make a difference - maybe 1 or 2 mph.
For plugs, try NGK B7S. If the plugs you have read too clean, then the floats in the carb may be set too low.
Here is a video of my Reinell with a Starflite 75 on it. I was able to wrangle about 40 MPH out of this setup. The propeller was an OJ small hub 2 blade for the 75HP gear case. Please pardon the low res video quality - the video is 7 years old and cameras have come a long way since then
I read your original post before you took it down, the previous owner changed the coil, I will have to check if the woven wire was changed. I have tried maxing out the angle to no avail .It had a large diameter 14 pitch prop on it and told me it would push his old 70's trihull boat about 38-40 mph. I sure haven't seen that with 1/2 the hull size and 1/3 the weight .I have a few boats and this motor is just plain gutless out of the hole. It couldn't suck the skin off a rice pudding !! It labors hard a long way with the bow up pushing water like crazy then finally drops the nose and slowly starts pushing the boat. I guess I will just start from scratch , check the points and timing, check all the float heights and main jets as well as the reeds. Like I said it starts and Idles great just doesn't make good power. I have tried a 14, 16, and 18 pitch 3 blade OMC props on it with poor results on all as well as the 14P large diameter prop it came with. I hope I find a glaring problem with the points or timing as to me it sounds retarded when trying to accelerate or possibly over/under fueling.. Hard to tell on that one. The hull is similar to my Meteor or Glass Slipper and I get about 30MPH out of them with 45 hp. I am shocked this motor wont take this hull into the mid 40's or even 50mph. I am bringing my boats in this weekend for the winter and will try some NGK plugs on the way to the boat launch, after that I will have it in the garage for the winter to go through everything. I was sure the Mighty 100Hp on that little hull was going to pull hard but so far not so... Thanks for your thoughts...Here are the 1966 Evinrude ads, they wouldn't lie would they, the one boat looks like its at "light speed" ...lol ... Brad
Acceleration should be brutal. With engine off - advance the cockpit throttle lever to full and leave it there.
The distributor body has a tab on it that should be firmly against the maximum advance stop. The stop is just a little rubber bumper on the distributor bracket, or your might have an adjustable thumb-screw stop. The distributor should be firmly locked against the stop.
Remove the deflector plate from the front of the carburetor. Get a bright flash light and look down one of the carb throats. The throttle plates should be wide open. There is a maximum opening stop bracket on the throttle plate shaft. This has an adjustable maximum open stop. The stop could be out of adjustment, not allowing the throttle to open completely
hi brad,, I just came from quincy boat show,there were several wood hull boats with 6 cyl merc, 1 guy ran 100 hp,before switching,when kevfin made your boat from the original wood hull it had same style of most of them,the style and chimes of bottom they don't think it will hit 50mph but 42 to 45 is possible,I don't know the ole guys but quincy was a speed town,,I know erik g3 with a 100hp merc,we tried a lot of props to get it to 50,,,my Allison has the speed type with the pad,,50 plus easy with 75hp..the bottom means a lot,,Good luck I know u will get all u can still looks great BILL
This story is really bugging me. Here is the deal - I have owned and have lots of experience with these motors, and I also have lots of experience with Mercury engines. I own many big Merc and OMC engines.
I can tell you with 100 percent certainty, that a properly set up Starflite 100 will out accelerate any Merc 1000. The Merc has longer legs, and will usually turn in higher top speeds. But these engines are monsters for torque. I believe that your throttle may be only opening up 1/2 to 2/3 of the way. In looking at your throttle lever in the cockpit, it appears ( at least from the photo ) as if the metal escutcheon on the center console will interfere with full throttle lever travel. Is it possible that the front edge of the console escutcheon is stopping the throttle arm from moving forward?
Hello Bruce. Thanks for your comments, I was careful that the consul name plate does not obstruct the throttle. In the idle and full throttle position there is about 1/8" clearance to the throttle arm on its built in stops. I am pretty sure my problem is tune up related as the motor labors so hard to try and get out of the hole from a dead stop. It literally labors for 15-20 seconds to start trying to get on plane at boggy low rpm. I have the boat back in the garage now for the winter, I will install a tach and use my trusty manual to go through everything.. Brad
Thanks Bill. My hull is quite "V'd" at the front and almost flat at the back with only a Center chine. Very similar to my Meteror or Glass Slipper that are going 30mph plus on 45 hp. Probably the difference is I went through those motors and set every thing myself with my Merctronic tester so I am sure the timing and points are set properly. Interestingly enough the Evinrude manual lists the Merctronic tester as one that can be used to accurately set up the Evinrude timing and points , they list a few testers that will work. The old Merc's can't be set up properly with out one, I believe the Evinrude can but using the Merctronic tester is more accurate. Hopefully I can sort this motor out this winter and solve the poor power problem as well as the left hand torque steer.. I would hate to have to put a Merc on a boat ment to sell Evinrude !!! Lol... Brad