3.5 tecumseh governor linkage ??

R

RedBeard

New Member
#1
#1
Hello there guys! New to mini bikes and am in need of some help.

Bike: Manco Tbird 3.5 tecumseh

After creeping on here for awhile i think all im missing is the linkage(part #37735?) to connect the governor to the throttle valve. So without that part the governor arm stays pulled towards the carb via the bottom spring. I can put some resistance on the arm and twist the throttle and it pulls back. My question is will that linkage hold the governor arm where it needs to be without holding the throttle wide open. Looking at it now it would seem that it would just push the valve open.

http://i61.tinypic.com/k9uq94.jpg[IMG]
[IMG]http://i60.tinypic.com/i2oac9.jpg
 
Last edited:
KustomKartKid

KustomKartKid

Administrator
#2
#2
Right now the arm is doing nothing to affect the operation of the engine.

The arm moves via centrifugal force (fly weight governor inside) when you start the engine and rev it up you will see that arm move away.

When you twist the throttle it actuates the throttle via a spring (your throttle cable should never be hooked directly to the buttefly)

The linkage rod (missing) allows the governor to pull the throttle back to a safe RPM range....it's sort of like tug of war between you and the governor...but the governor always wins if adjusted properly. The governor wins because the arm is a big lever and has the advantage. How much advantage (and how much governing) is determined by what hole you place the spring hook in.

If you don't have one you can make your own out of a piece of music wire with a couple of "z" bends on the ends....but the proper length is necessary.
 
jrzmac

jrzmac

Active Member
#3
#3
KK's right, your missing the governor linkage rod:


it connects your throttle to the carb. if it's not hooked up, your throttle isnt doing anything. KK's said it exactly, it's a tug of war. you pull the throttle andd the governor pulls back. it's only supposed to spin at 3600 rpms. and when yoy start getting close, the gov. pulls the throttle plate back with the spring.

here's how it should be hooked up:









in a pinch, I've used a straightened out paper clip, bent exactly like the original one, with the "z" bends at the ends too. works fine, at least for a while!
 
R

RedBeard

New Member
#4
#4
thanks for such quick and great responses! So basically with that linkage in it would hold the butterfly valve wide open untill it is started?
 
jrzmac

jrzmac

Active Member
#6
#6
RedBeard said:
thanks for such quick and great responses! So basically with that linkage in it would hold the butterfly valve wide open untill it is started?
Click to expand...
no, it should be closed. until you give it gas with the throttle. if it was wide open, when you started the engine the bike would take off on you! you want that butterfly in the closed position when starting.
 
R

RedBeard

New Member
#8
#8
yea i gotcha. i got the part in the mail so well see. What i'm trying to say is theres a shit ton of tension on the governor via that spring that runs under the carb, and by putting that linkage in it seems like it would hold the butterfly valve wide open. As of right now that spring is pulling the governor all the way to the the right towards the carb. I can pull the governor lever arm back and twist the throttle and everything seems fine, but whats going to hold the governor back? Just the linkage? I heard mention of centrifugal force...
 
jrzmac

jrzmac

Active Member
#9
#9
your gonna have to post some pics. it might have the wrong spring under there. the governor is not supposed to be all the way to the right, under tension. just the opposite. it should be all the way to the left. then the throttle would push it over to the right. when it hits a certain rpm, the gear inside the engine pushes the gov arm back to the left. basically when the engine is off, the gov arm should be to the left, and you should be able to pull down on the throttle and that spring should move the gov arm over to the right. that moves the rod linkage and pushes the throttle plate on top of the carb over to the right. giving the engine gas! ALL of these things should happen with ease and there should be no hangups and nothing should be sticking at all. it all should move freely witout anything binding. if it doesn't, it has to be dealt with before starting the engine, or the bike can go flying right out from underneath you! post some pics so we can see whats going on.
 
R

RedBeard

New Member
#10
#10



first pic of the gov how it sits right now all the way to the right, second me pulling the gov all the way to the left. I can take that spring off and the governor moves freely but doesnt reset or anything. I have the spring in the 3rd hole just cause it has the most wear on it. Pretty sure it should be the 4th hole.
 
jrzmac

jrzmac

Active Member
#12
#12
it has the right governor spring on it, just might be a little too short. you can stretch it out some. so the gov arm isnt all the way over to the right. find yourself a paper clip and straighten it out and cut it down to try to make a rod like the one I posted. put it in the right holes and see if it'll work.
 
R

RedBeard

New Member
#13
#13
Alright i got it all rigged up with a paper clip and i stretched the spring. Rigged it so the governor is all the way to the left at start up. Runs ok, a lot better under load. Now im just trying to figure out the screw settings on the carb because i messed with them so much. Are they both 1.5 turns out?.
 
jrzmac

jrzmac

Active Member
#15
#15
RedBeard said:
Alright i got it all rigged up with a paper clip and i stretched the spring. Rigged it so the governor is all the way to the left at start up. Runs ok, a lot better under load. Now im just trying to figure out the screw settings on the carb because i messed with them so much. Are they both 1.5 turns out?.
Click to expand...
screw both screws all the way in. back the bottom one out 1-1/2 turns. the one on the side of the carb 1 turn out. that should get it started. then with the back wheel off the ground, you give it gas and turn the bottom screw in and out until it runs smooth. then let off the throttle and at idle do the same thing to the side screw.
 
R

RedBeard

New Member
#16
#16
thanks jrz!..., got it running smooth. Another hiccup occurred. A buddy of mine just took a spill about 2 hours ago and there is gas gushing from what looks like a manufactured hole in the carb. In the last pic of jrzmac first post the is a backwards "s" on the carb and a hole above it. The gas was gushing...going to order a rebuild kit?
 
jrzmac

jrzmac

Active Member
#18
#18
Buckeyes right, the thing is flooding now. do you have a gas shut off valve somewhere between the tank and the carb? if not, you need one. you're gonna have to take the carb apart again and make sure the float is able to move up and down and that the needle is still attached to the float and is still shutting off the gas when it's up in the seat!!!!
 
R

RedBeard

New Member
#20
#20
alright so put the carb back together and went around the block a few times. started leaking agian for a few seconds and stopped, my wife the went around the blocks a few times. parked it and watched for a few minutes and it seemed fine. 10 minutes later gushing.
 
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