Thanks
I did change the tuner to the M50D tuner. This was originally a 2004 M40D2 motor. There are 3 tuners for this motor. M40D is the smallest, (M40D2 & M50D2 are the same), and M50D has the...
Type: Posts; User: camohunter; Keyword(s):
Thanks
I did change the tuner to the M50D tuner. This was originally a 2004 M40D2 motor. There are 3 tuners for this motor. M40D is the smallest, (M40D2 & M50D2 are the same), and M50D has the...
I found out later that the 60 carbs have about the same bore as the stock Tohatsu 50 carbs. The 70 Yamaha carbs have a good bit larger bore.
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Update: My motor runs really good. It’s the best idling motor I’ve ever owned. I’m seeing speeds close to 50mph on my Edge 553 duck boat.
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Finally got the powerhead on!!
Getting the Yamaha carbs to work right is yet to be accomplished
Yes.
I'm porting the reed block cages. I'm not sure this will prove to be a good idea. What do you think?
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Got my reeds in today. Boyesen Power Reeds. They don’t look like what I expected. They were my second choice after Chris Carson reeds. Chris would never return my call or text after the first time...
This was done with a rotary file and a die grinder. I sanded and polished the surfaces after these were taken.
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I did not do the port work. Pete Nydahl in Wisconsin did most of the work on the block. I highly recommend his work. The ports were widened a good bit.
I think you are right. From my research I found that the Yamaha 60 and 70 intake manifold and gasket is the same part number. That would seem to indicate that the carburetor throats are the same...
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Here's one of my yamaha 60 carbs with the chokes removed. They are a good bit larger in diameter than the stock 40 intake. I wanted to use 70 yamaha round bowls, but couldn't find any...
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Installed some socket caps on the exhaust cover
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Painted last night
I finally got back on this project. I dropped in the crankshaft and bolted it up last night. Afterwards, I realized I had not checked the Wiesco piston rings to see if they were of different types...
Thanks Jerry that's some good info. I see u are in WI. Pete Nydahl, from WI, rebuilt the crank on this motor and did the block work.
My first rebuild a M40d2. Already done the following:
-Bored .30 over
-wiescos in hand
-Ported and polished
-crank rebuilt and welded
-flywheel lightened
-head cut
I think I'm ready to...
Thanks everyone for the good advice. I'm going to try rechecking the compression first. My $15 eBay tester may not be accurate. I think pulling the welch plugs on the carbs is a must also. I did...
Ok I'll pull the welch plugs on the carbs if the compression checks out right. I've got to find another tester to verify my readings.
I didn't know it was common to pull the welch plugs but I'll try that because the crankcase backfire is what's happening
I've got several of the 20"ers and the parts to build a short. I have a clean looking 49 powerhead for my short but I'm thinking about getting a 56 to go on it. 56s are $ harder to come by here. I'm...
A guy on here who worked for OMC said all the 75hp models came from the factory with raised ports, cut heads and I think bigger carbs. I'm not sure about the psi.
My motor is SPECIAL :mad: LOL...
I didn't pull the welch plugs. I'm sure that's sound advice. I did pull all the brass orfices and made sure the passages were open. The "cam follower" is there and seems to be in good shape.
I live in Wayne County on the Altamaha River.
I've had the carbs off and adjusted the linkages and stuff when I installed the tiller handle, so that could be the problem. I really don't think...
Can the reed valves affect the compression readings?
I've got a 1980 75hp Johnson Stinger 20" club foot on a 1652 aluminum boat. I've ran this motor a good bit in the last year and it always runs really strong and fast, but will not idle very well....
I been interested in this thread for a while. Any updates?
It will go on a 16' aluminum boat that weighs around 300 pounds. They've got one now with a sort of vee pad hull like a bass boat. I've got a 30" tiller handle that I may put on it. I will often...
Finger ports are one the intake side right? I saw where you marked yours with the dye. Do you cut your own or send to a machine shop. How the hell do you get in them cylinders to cut?
Thanks guys for the good information.
What is the difference between the aftermarket adapter plates and the stock plate off a long shaft mid section? Is it something with the drive shaft length or the exhaust tuner?
Is the adapter plate for the 56 something aftermarket you buy to make the poweRhead fit?
I'm Building an OMC 75 Short Shaft Hustler/Stinger. I've taken a lot of notes from this site, but still need advice on what I should do. This motor will be a river motor and probably be used on one...
So the wrist pin hole in the mod 50 piston is closer to the top to allow the longer rod? OR does it extend past the deck into the cylinder head? I'm new at this trying to learn how to build a...
That's good information. I'll see if I can find the 15"mid. So I should be able to build the nitro case out of a 40/60 short by changing the drive shaft and associated parts?
Stephen thanks for the info. I'm in the States, Georgia. I've never seen one of the short midsections. I know they exist, but not many around here. I have a lot of the 49ci parts. I love the 49...
What would have to be done to swap out the powerhead on a Johnson/Evinrude 2cyl and replace it with one of the 49 or 56ci 3cyl? Is this possible?