Help needed. Murray Track 2 mini bike. I have a few questions.

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Freebeer

New Member
#1
#1
Hello everyone at OldMiniBikes.com! I am new here and I have owned a murray track 2 mini bike (techsum 3.5 hp engine) for over 7 years. The bike has been great to me. It seems the build quality is excellent! The engine is a becoming a little tired this year. I ran it today after it being dormant all year. For the first few minutes it was spitting out thick blue smoke. After pouring in fresh gas, a little throttle body cleaner, it eventually stopped. Not sure what that was about.

Anyway, I am in DESPERATE need of a brake assembly for the bike. The bike currently does not have a brake cable. I found an assembly locally by me, but on the brake cable, the barrel end (litterally, it looks like a steel barrel) is too big to fit in the handlebars. I do have a new break pad though. Does anyone know where I can purchase one?

Also, I was at first interested in re-building the motor (not knowing much about these things) and found that parts appear to be difficult to find. What I did find from searching this forum were these two engines (i think they are the same?)

6.5 HP Gas Engine - CA Certified
6.5 HP Gas Engine - Horizontal Shaft, OHV

The price is definitely right on these guys. I would like to pick one up and install it into my existing frame. My question is, what would I need to do this? Would it be just a direct swap (ie just use the existing hardware bolts and such?). Would I need a new chain and sprocket?

So to sum it up, my questions are:
  • Where can I find a new brake cable/assembly for a Murray Track 2 mini bike?
  • Will the posted engines work in my Track 2 mini bike?
  • Will I need any additional hardware to complete the installation?
 
F

Freebeer

New Member
#2
#2
This seems to be the picture of the bike with the upgraded engine installed. Do you guys think I will need a new sprocket/hardware/ and chain or will it be just a unbolt old engine/install new engine deal?

 
mmisterbungl

mmisterbungl

New Member
#4
#4
you might need more chain if anything? make sure you get #41 size chain. other than that, all the bolts that hold your 3.5HP engine down will work to secure the new engine to the bike. I dont know if the stock muffler causes a fitment issue in these bikes, but I know you can't run the stock air box (the plastic cover over the filter), as you can see in the pic you posted, it was removed to allow for the room it needed to sit in the chassis. Now if you go all out some day and go aftermarket air filter, header and gas tank, you will have NO fitment issues whatsoever, but will need to get creative with a header that fits. :thumbsup:

As for your brake issue, what parts/pieces are you missing for yours?


 
F

Freebeer

New Member
#5
#5
jrzmac said:
http://www.oldminibikes.com/forum/project-logs/30467-my-murray-bike.html
Click to expand...
mmisterbungl said:
you might need more chain if anything? make sure you get #41 size chain. other than that, all the bolts that hold your 3.5HP engine down will work to secure the new engine to the bike. I dont know if the stock muffler causes a fitment issue in these bikes, but I know you can't run the stock air box (the plastic cover over the filter), as you can see in the pic you posted, it was removed to allow for the room it needed to sit in the chassis. Now if you go all out some day and go aftermarket air filter, header and gas tank, you will have NO fitment issues whatsoever, but will need to get creative with a header that fits. :thumbsup:

As for your brake issue, what parts/pieces are you missing for yours?


Click to expand...
Thanks for the fast replys!

minibikedude - Is that the same/similar engine which I am refering too? Is there any extra hardware that you needed to complete the install? What did you do regarding the air filter and fitting it?

mmisterbungl - Im looking simply for the brake cable. The cable that runs from the handlebars to the brake pad in the rear. I need to double check, but im pretty sure I have the pad at home. Also, since the air box will not fit, is it ok to run the engine without the air filter? The 3.5 I have now has pretty much never had an air filter :doah: but it has ran fine.

Also - one more question. Will there be a new throttle assembly (springs and such) on the new engine?
 
mmisterbungl

mmisterbungl

New Member
#6
#6
Freebeer said:
mmisterbungl - Im looking simply for the brake cable. The cable that runs from the handlebars to the brake pad in the rear. I need to double check, but im pretty sure I have the pad at home. Also, since the air box will not fit, is it ok to run the engine without the air filter? The 3.5 I have now has pretty much never had an air filter :doah: but it has ran fine.

Also - one more question. Will there be a new throttle assembly (springs and such) on the new engine?
Click to expand...
If all you need is a brake cable, you can go to any bicycle shop, they sell the black cable housing by the foot and you can also buy a cable there too. However the Murray, in it's stock hardware configuration has a particular little loop type fitting at the end of the cable for the brake. But you can make something else work in it's place with the right parts.
Check out post#10 on this thread
http://www.oldminibikes.com/forum/g...7635-murray-tr2-mini-bike-brake-assembly.html


I wouldn't run an engine without an air filter unless (and that's even iffy) you're running strictly on asphalt.

For the throttle, that's a whole 'nuther can of worms. I'll see if I can dig up some links to help you with that one. Short answer is, YES, you will need to rig something up or buy a kit that is sold by a couple of places online specifically for the Harbor Freight engine.
 
mmisterbungl

mmisterbungl

New Member
#7
#7
Here is something that you can use for the brake if you don't have the original cable.

Band Brake Pin - AZ2254
This pin goes in the place of the bolt you see on the original set up. After that, you just put the end of the cable into the little hole and tighten down the allen screw on the cable.

this is a small picture, but you can see I used the same exact brake pin in this set up.
 
Evilution

Evilution

New Member
#8
#8
I'm actually doing this swap right now, and had to get VERY creative with my throttle connection simply from lack of funds. The stock muffler definitely doesn't fit, and the way I ran my throttle causes the stock air cleaner not to fit, so I'm working on that now.

The throttle that comes on the engine is a lever, more suited to pump or tiller duties.
 
F

Freebeer

New Member
#9
#9
I see. Thanks for the info! im going to look into it now and see what hardware I have at home.

What do you suggest I do for a solution for the throttle assembly?
 
Evilution

Evilution

New Member
#12
#12
For now, it just runs. I changed to a #35 clutch and sprocket, and my clutch springs are too soft. My 3.5 was BEYOND tired, so I'm positive this will be better. If not, there's tons of upgrades available.
 
F

Freebeer

New Member
#13
#13
mmisterbungl said:
Here is something that you can use for the brake if you don't have the original cable.

Band Brake Pin - AZ2254
This pin goes in the place of the bolt you see on the original set up. After that, you just put the end of the cable into the little hole and tighten down the allen screw on the cable.

this is a small picture, but you can see I used the same exact brake pin in this set up.
Click to expand...
Bought the pin :thumbsup:
 
minibikedude

minibikedude

Active Member
#14
#14
Freebeer said:
Looks good man! How does it run now? Is there a nice power diffrence from the 3.5 to the 6.5 hp engine?
Click to expand...
Night and day difference. The clones are powerhouse engines for what you pay for them. I re-geared my Murray bike to 35# chain size,12 tooth front, 66 rear tooth. Its a lot faster than it came from the factory, I need to upgrade my brakes because it doesn't stop to great with the higher speeds I run it at now. Stock Murray gearing is #41 chain size, 10 tooth front and 72 rear that is too low when running a clone in it, It want to lift the front wheel real easy and not have a lot of top end. Plus you got the pizza sized rear sprocket to deal with that hits the ground in a hard turn.
 
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