Looking for information on McCulloch Mc-49-C

[Scott Kneisel]

Sounds good Dick. I will also have 2 49ers to choose from, one has some fin repair on the head, the other is pretty much perfect so that will be a display and the rough one to run. I only have 2 karts now, my R1 will have twin Mc20's at TBO and My Dart GP that I am finishing up this winter will have a 101A if all goes well but I will bring some other engines to switch out on the dart and the 49 will be one of them. Right now I have a Tilly on it with a 7/8" venturi so I guess that is OK. Mine are modified a bit but are stock appearing. We should have a good time!!

[Scott Alto]

if i get to the big one,can i play to? i have a 49e
Scott

[Dick Teal]

Guys,

It sounds like we'll have a lot of fun and Voska will have to get a 49 also. He works too much and we have all of the fun. If he doesn't have a 49 I'll let him run mine.

Dick Teal

[Jacob Jay]

Scott K.- do you have anymore of the 49 badges? I could use one. I'm going through a single that's original.

[Scott Kneisel]

Jacob,
Send me an email or private message and I will fix you up.
Scott

[John Miller]

Thank you for the replies... Does anyone else have anything to add? I'm mostly interested in learning the background behind this model, the R&D that led up to it & how it ranks, or fits as compared to the McCulloch engines both prior to & later.

As far as modifications... I'm not looking for the high end super trick stuff. Just the common type of mods or parts swapping that was performed to enhance performance or reliability.

Please take a look at the pictures that I posted & advise me on how I should proceed. There is at least one broken cooling fin, plus one or two bent ones. I had thought to simply "dress up" the broken one with a file, or grinder, to smooth it out. How are bent fins usually handled? Is there a high rate of success at trying to straighten them without them breaking? If so, what seems to be the best technique?

[david a luciani]

the bent fins like to break off if you move them in my experience,
dress the raggy edge of the broken ones but save as much as possible.
they're there to cool the engine so pretty doesn't count in my book.

DO NOT ATTEMPT THIS IF YOU"RE THE LEAST BIT UNSURE YOU CAN RUIN THE MOTOR

simple mods would be opening the exhaust ports by squaring but don't attempt unless you've a steady hand.
and just square the center port and inner ports section of the ribs left and right.
you're aiming for an oval shape overall so leave the outer e-port edges as found.
do not change the height or lower them either.
just dressing the ribs should be plenty to get the exhaust flowing a little better.

these mods below are better to do:

you can also lap in your pto side for the clutch and check the fit on the flywheel side it should already be tight.

flat sand all gasket surfaces (with 220 or finer) that don't have raised sections on a piece of glass or "dead flat plate" if you have one.
the idea is to seal the motor perfectly so hit the base the inner flywheel gasket area,the head surfaces and intake surface.
all flats on the carby and intake parts including the reed areas.
go slow check progress every ten strokes - use a figure 8 pattern in the sanding and keep the part flat on the paper.
don't forgat to mark up the surface you're sanding with dycum blue or sharpie ink.
you're done when it comes clean of ink.
replace all your seals and run loose bearings maybe #4 friction is the enemy of two strokes.

hope this helps
dave

[Jeff Campbell]

... just a reminder



Also, Scott's excellent MC8 rebuild article has a lot of information that can be applied to any McCulloch engine.


David is right, it is easy to break fins trying to straighten them. You can move them a little bit, but not a lot, and if they are cracked, they can't even be moved a little. David has it right, clean them up, but don't try to move them much.

The MC49 does not have a detachable head, which makes it difficult to bore / hone, you need to find someone with the right equipment for this. For any small 2-stroke motor, getting the bore true and properly fitted with a piston and rings, is a huge part of the performance puzzle.

I was at Brodhead this year, and I took my Fox kart with a MC49 on it, it was a load of fun. The older tracks are very well suited to the lower power engines, you still have to drive well to get around fast.

Jeff

[Scott Kneisel]

John,
I agree with Dave and Jeff about the fin thing. I can't tell you how many of those I broke off trying to straighten them so they look good. I finally learned after having some welded back on at the tune of $50 and then welding them is iffy on the cast aluminum. Best just to leave them alone.

Here is all I know about the Mc49:

Introduced in 1970 along with the Mc91B and the Mc101A.

I am not sure what nitch this engine fit since it was so much smaller in displacement had only about half the horsepower as the Mc91. I suppose it was a good fit for rookie and junior class racers although when I was a junior in 1963 I ran an Mc8 which was considerably more powerful. Times had changes I guess, I was not racing in 1970 so I am not sure but some of the younger people I know started out with the Mc49.

It is a very durable engine because it is a full bearing engine with ball and needle bearings throughout. The very low compression ratio of 6:1 also made this engine easy to pull over with a recoil starter which was a plus for beginners.

I have built up a couple 49's and will be taking one to TBO next year to run with others who have chimed in on this post. Sounds like it will be a little Mc49 competition which will definitely be fun because driving will be key as Jeff has said in his post and I am not the greatest driver; sooooo, the engine I am bringing has stock ports but I am thinking I will bolt on some performance equipment like maybe a dual carb manifold such as a VanTech and a GEM super stuffer and box muffler. If you decide to do something like that with yours, keep in mind that this engine has 3rd port induction so you will need to use an older style manifold that will get some fuel into the 3rd ports in order to properly lubricate the wrist pin bearings. A Van Tech works well, Palmini made some nice manifolds that fed the main and 3rd ports thru a pyramid reed assembly. An Mc45 manifold with the GoPower reed will work as well as an Mc40 dual carb manifold. Just some ideas.

So anyway, I don't know if any of this helps but I am grateful that you started this post because it really generated some serious interest in the Mc49. I know it did that for me, I can't wait to try mine out!!!
Take Care,
Scott

[Scott Kneisel]

John,
I forgot to say the the McCulloch model 250 chainsaw used the same #62481 block as the Mc49 series, not the super 250, the regular model 250 saw.

One correction on my previous post, I think the 49C came out in 1968 according to the date on the IPL that I sent you. Did you get the documents I sent you when this post started?
Scott