Can I bypass the governor linkage, (by just removing the spring from the throttle arm and connecting a solid linkage) and limit my rpm to 4500 with the high speed stop? I am not wanting to split the case yet to pull the governor, and don't want to buy a billet flywheel yet either. I am just getting tired of my throttle bouncing badly when I hit ruts and bumps. It almost kills the kart when I am in a long wide open throttle run. I am afraid I know the answer, but I had to ask anyway. I was looking at the 26mm (I think) mikuni carbs from NR Racing to replace my stock carb.
420 predator governor linkage question
- Thread starter Grimace
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Doc Sprocket
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Don't simply bypass it. Either remove it complete, or leave it alone. Bypassing it can be rather risky. Grab a beverage of choice, and settle in for a read- http://www.diygokarts.com/vb/showthread.php?t=16518
Thanks TS. I have read that sticky several times, and I guess I was trying to fool myself. My problem is the carb itself. When I hit bumps and the rear wheels lose traction, the governor does its dang job and kills the throttle, then the tires hook up and the throttle pops open again. Doesn't sound too bad, but imagine it doing that every other second. It literally tries to kill the engine, and I have to coast with my foot off of the loud pedal until it stabilizes again, and I can get back on the fuel. During a race out here, if I can't keep hard on the fuel, I have no chance. Can I limit the throttle to 4500 rpm if the governor is removed, or will it just run faster and faster until I let off? I really don't want to buy a billet flywheel, the ones I have seen either have provisions for the recoil start, but no ring gear, or ring gear only with no way to pull start. Sorry so long, I am just rambling.
Doc Sprocket
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What about looking at things from a different perspective? If you're butting heads with the governor so frequently, perhaps you could stand to gear up a wee bit?
I did that, I stepped up from a 10 tooth driver to a 14 tooth. It was WAY worse with more of a load on the engine. I went back to the 10 tooth, and at least now it isn't as bad. I guess I need to just bite the bullet and get rid of the governor.
jamyers
Well-known member
Going from a 10 to a 14 is a BIG jump in gearing, nearly 50% bigger on the driver.
If you can get one, might try an 11 or 12...or slightly taller tires would yield the same results.
Have you played around with the formulas in the "tires, gearing, and speed" sticky?
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If you can get one, might try an 11 or 12...or slightly taller tires would yield the same results.
Have you played around with the formulas in the "tires, gearing, and speed" sticky?
Sent from my iPhone using Tapatalk
Yeah, I read the stickies. I guess I will have to sit down with pencil and paper and do some of them maths I heard about. Can't go up in tire size, they will hit the swing arms. I am sitting on 18 inch rubber now, and the 10 tooth is great for getting out of the hole, and out of corners. It looks like I will get the governor gear off and plug the hole in the case. How can I limit the rpm to around or under 4500 rpm with the stock carb?
Doc Sprocket
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You're gonna like this. Gearing. Best way to keep RPM in check.
You're probably best to just go down a few teeth on the axle sprocket count.
You're probably best to just go down a few teeth on the axle sprocket count.
It's a 60 tooth, should I drop to a 54 or so? I really like the gearing the way it is now, because last time I stepped the gearing taller, it made the bounce a bunch worse. The taller gear ratio makes the throttle really bounce, but a low gear ratio makes it not very bad, just annoying. I will try gearing after the snow storm goes away. Just a quick question, would the mikuni slide carb be better for my setup, or will I have to stick with the stock carb and deal with the bounce?
It seems like the lower gear ratio gets it topped out on the governor while the taller ratio doesn't get quite up to the top of the rpm range, therefore the governor flutters trying to maintain the work speed while I am bouncing over the trails. I just want to get rid of the stupid throttle flutter so I can keep the tires hooked up to the ground.
Doc Sprocket
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Here's a little trick you should try, to give you a better picture of where you're at with your gearing:
Tie a length of string or something to the governor arm- do it in such a way that you can override it from the driver's seat. On a long, flat stretch of road, drive at wide open throttle to top speed, and keep your foot to the floor. When you attain top speed, go ahead and pull that string. If the kart begins to accelerate again, then you had some room for gearing in there. You could safely go to a slightly smaller axle sprocket. This also indicates that at your current gearing, you would see a top speed increase by removing the governor. If there is no increase in speed, then your gearing is limiting the RPM, not the governor. You can either keep it as is, or go to a larger axle sprocket.
Either way, only do this for a second. If you push your luck, you may break something.
The more I re-read your posts, the more I think something is not right. Governor may be out of adjustment, and or a weak spring. Maybe your low oil sensor is barking at you. Gearing down may cause you to bounce off the pin, but gearing up should not. Unless, your kart is bouncing so dang hard that ALL load is being removed sporadically. If that's the case, it seems to come down to remove the governor, or live with the surging.
Tie a length of string or something to the governor arm- do it in such a way that you can override it from the driver's seat. On a long, flat stretch of road, drive at wide open throttle to top speed, and keep your foot to the floor. When you attain top speed, go ahead and pull that string. If the kart begins to accelerate again, then you had some room for gearing in there. You could safely go to a slightly smaller axle sprocket. This also indicates that at your current gearing, you would see a top speed increase by removing the governor. If there is no increase in speed, then your gearing is limiting the RPM, not the governor. You can either keep it as is, or go to a larger axle sprocket.
Either way, only do this for a second. If you push your luck, you may break something.
The more I re-read your posts, the more I think something is not right. Governor may be out of adjustment, and or a weak spring. Maybe your low oil sensor is barking at you. Gearing down may cause you to bounce off the pin, but gearing up should not. Unless, your kart is bouncing so dang hard that ALL load is being removed sporadically. If that's the case, it seems to come down to remove the governor, or live with the surging.
That's exactly what's happening. I am hitting 40+ on the straightaways, and the rear end starts bouncing pretty badly. That's when the governor starts bouncing and trying to govern the load. I guess I am gonna have to live with it. I will try the string trick but I can tell you that I am hard on the governor when going down the straights. Pulling a string might stop the bounce, should I try adjusting the spring from the throttle arm to the governor arm? The other rod, from the governor to the carb is fine, with the tiny spring still in place. The engine is fairly new, with only a few hours on it. But the print from the throttle arm to the governor is kinda loose, it may need shortened a bit to take up the slack.
jamyers
Well-known member
You're going to want to get that sorted out before much else, or you could find yourself bouncing along without wheels between you and the ground - Ouch!
Tire Pressure, something out of balance, need better shocks (if you have suspension), etc.
Do you really want to go faster than 40+ on a road with ruts and bumps??? Maybe it is not the best idea
I don't want more speed, just constant power without the throttle cutting out.
My kart is a full suspension kart with new gas/hydraulic coil overs, and 18 inches of rubber. It's bouncing because I am hauling a** and hitting bumps/ruts. We all have full roll cages, and wear helmets. I have a wife and two kids to worry about.
My kart is a full suspension kart with new gas/hydraulic coil overs, and 18 inches of rubber. It's bouncing because I am hauling a** and hitting bumps/ruts. We all have full roll cages, and wear helmets. I have a wife and two kids to worry about.
Have you thought of letting some air out of the tyres to give you a slightly softer ride?
fowler
New member
Is your low oil sensor still connected?
If u remove the governer then the next barrier it will hit is around 5k
This is when u start to get valve bounce
If u remove the governer then the next barrier it will hit is around 5k
This is when u start to get valve bounce
jamyers
Well-known member
Well, there's yer problem, lol!
Might well not be the governor as much as the carb cutting out when the fuel in the bowl gets thrown all over the place inside there - that's the issue I have with el Texas Terror on rough terrain, although on mine it's bad enough to flood out completely.
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