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Old 10-31-2018, 07:50 AM
MaineBeerMan MaineBeerMan is offline
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Default Murray Exploer sprocket question

So, I just got an old Murray Explorer. It had a 5 horse snow blower motor on it that pushed it to about 10ish mph, not great. I put a new Predator 212 on it and it runs very smoothly and consistently but still, about 10ish mph. it has a torque converter attached to a jack shaft with a 10 tooth sprocket and a 60 tooth sprocket turning the solid axle. So.. should I, 1. disable the governor or go the drastic route and remove it. 2. replace the 60 tooth sprocket? 3. the jack shaft sprocket?
As for sprockets, I don't see many that are designed to just slide on like the original. Should I get a sprocket hub and 2 piece sprocket, and if so, which one? Thanks for your help in advance!
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Old 10-31-2018, 03:06 PM
J.S.@SMS J.S.@SMS is offline
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What size tires does it have? Tires that are too small will equal a low top speed.

And if you do alter the governor, don't leave any part of it in the engine. Remove the governor wheel and the arm thats inside the crankcase, and drill the hole out to 1/4". Than tap for a 5/16" x 24tpi bolt. That's the same size that's used on the sidecover. Then bend either a piece of similar wire, or the original throttle linkage bar, to operate the throttle on the carburetor.
Here's a video, in case you don't understand my instructions on the throttle linkage.


One thing that I did on the engine that I used this setup on that he did differently is that if you have a file you can file down the plate and if done correctly you can use the outer most existing hole. This will give it a much less touchy throttle. I will post a pic of my setup asap.

Failure to remove the governor wheel and, or the governor arm (inside the case) can and will cause the governor to fly apart inside of the engine at high speeds, resulting in damage to the internals. And the governor arm that's inside of the case can interfere with the rotation of the crankshaft. Both of these can cause a blowup.
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Old 11-01-2018, 01:07 AM
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landuse landuse is offline
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Please post some pics so that we can see what you have> what is your low end torque like? Do you nearly pop wheelies?
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Old 11-01-2018, 03:15 AM
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itsid itsid is offline
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there must be something terribly wrong with your Torque converter setup or your kart in general.

the murray explorer came for All I know with that EXACT same setup..

an engine that turns 3600 rpms,
a series 30 Torque converter
a 6:1 gear ratio (10 tooth TC out and sixty on the axle)

And with it's 18" rear wheels that means it does 36'ish mph!

As you can see.. it's far from ten'ish speeds

Even if your engine isn't accelerating properly
say it only barely revs above engagement speeds (say 2500 rpms)
if the TC would work properly it should get you up to 22'ish mph
(as it would with a simple cent clutch)

Taken that... it sounds to me, like your Torque converter is stuck in low gear
(i.e. it doesn't change it's internal reduction)
which in turn would mean it's reducing the speed by a factor of 2.7 and you only end up with 13'ish mph..

See why I think it's the Torque Converter?

So, what next?

Pop up the rear of your kart (put it on SOLID stands),
remove the TC cover,
put your wife/kid/friend in the front seat and have him/her rev up the engine.
Observe the Torque Converter, is the belt moving properly up and down the sheaves of the two pulleys?
Does the belt reach the outer edge of the Driven pulley?

If so, you must replace your belt, since it's likely too worn out to do the same under load.
if not, post pictures of the Cam of your driven,
check that the spring is not pretzeled up and the six rubber buttons are still in place.
(if the cam slipped past these buttons it can be ruined and locked)

If that's okay, remove the bell of the driver pulley and check the garter springs and weights,
remove the belt and measure it's top width (3/4" or replace with original Comet belt or designated series 30 Torque converter belt! [NO automotive V-belt crap!!!])

And since the belt is off.. try to move the outer sheave of the driver, it must move nicely towards the engine, until it almost touches the fixed sheave,
else you will need to clean the TC and do full maintenance.
(clean all sheaves baby smooth dry lube only and JUST on the weights [a hair on the small clover hub doesn't harm])

Post pictures in case you are unsure,
we can identify the parts you need, and things you should work on from there.

Spare parts (weights, springs, buttons) can be found on mfgsupply.com or gokartsupply.com

'sid
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Old 11-05-2018, 04:05 AM
MaineBeerMan MaineBeerMan is offline
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I tis indeed the torque converter. ordered some new buttons and spring. Now if I can just get the preload right Ill be in business. will post pics as soon as I take some. Thanks again!
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Old 11-05-2018, 06:36 AM
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preload is easy.. when you got the new spring in place and the ends properly in their holes.
before pushing the cam all the way onto the post,
turn the moveable sheave clockwise,
so that the spring TIGHTENS
bring the buttons past the points of the cam into the next valley,
push it down and secure it with the snapring while holding the tension.

'sid
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