Tensioner?

[ineed2fly]

Ok, so if I have this link in it's too loose, if it's out, its too tight, so I need a tensioner pulley right? If so how do I mount this?

Thanks,
NPW
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Does anyone know how I can find the RPM's of my engine, I am trying to figure out my speed.

[robertdjung]

Put some washers between the engine and the mounting plate.

Looks like a normal OHV engine, standard RPM is around 3600 if governed. Take it off and you'll get 5000... But be careful.

[ineed2fly]

That is a good idea! I already have some 1/4 rubber washers in there though.....is that going to get out of hand with like another 1/8 on there? Or should I go into my mounting plate and cut chanels, and then slide the engine back? It's a B+S 5.5 OHV, and I don't believe it's governed, there was a whole linkage under the gas tank I couldn't get back together, so what should I do to make it not explode?

[my_mini_bike]

Yes, that could work
An easy way to do it is to drill two holes.. and cut the middle out with a metal bit on a jigsaw.
Or alternativly, using 4 pices of flat bar.. Welded in such a way that the engine mount bolts fit inbetween the two bars and can slide back and forth
...||...........||...
...||...........||...
...||...........||...
^ ^
Egnine can move backwards+forwards/ajust in these chanles and give you your ajustment

Get me??

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[ineed2fly]

Yeah I was thinking with the channel to drill 2 holes an inch apart, and then dremmel out the inside in a straight line. What is the risk of running my engine as high as it will go ungoverned for short periods, like 10 seconds, I wanna go fast! :D

[kibble]

Yeah I was thinking with the channel to drill 2 holes an inch apart, and then dremmel out the inside in a straight line.

That's what I did on the plate I made for mine and it works like a charm! Use a file to make the slot more even on the sides so that the bolt going through doesn't snag on the rough edges.

[I like karts]

What is the risk of running my engine as high as it will go ungoverned for short periods, like 10 seconds, I wanna go fast! :D



It will esplode if you run it at full ungoverned throttle for too long. Like this: clicky (http://video.google.com/videoplay?docid=3139510222636141062&q=plastic+engine&ei=umVJSJqoMpO0rgLP-ZyXDA)

[ineed2fly]

Ok, so I cut the slots, and got it much tighter, and then cut some wheels out of 1/4 inch ply and drove around the street for all of 10 seconds until they turned into ovals. Problem is the chain keeps coming off, is this because the kart is bouncing so much it flies off? Or is something wrong? Like when I put the chain on it looks good, but when I hit the gas, the top goes tighter, and the bottom sags. That can't be right can it? Do I need a tensioner on the bottom then?

[2or3wheels]

you need to make the chain tighter or a tentionser.

[Kenny_McCormic]

Problem with running an ohv ungoved is if the engine revs past what the valve springs are capable of the valves will stay open too long and get hammered back in by the piston which is pretty much guaranteed to bend them. Flatheads will just stop reving faster because the valves cant be hit by the piston, but take a stock flahead rod past 4k(about what the stock valve spring limits you to) and its gonna break the oil flinger eventually.

[jr dragster Tyler]

your rear axle sprocket looks a bit small. And yes a chain should NEVER fall off ANYTHING.

[ineed2fly]

It is a bit small, not much aceleration, but better top end, I got it kinda working today, I need the tensioner for sure, but it stayed on for a good minute of straight running. And then the tire fell off, rolled past me, hit a car, and trashed the threads on the end of the axle....oops So now IDK what I can do to fix the threads. But with all that torque on the engine at even a good 10mph it doesn't rev very high at all, even flooring it when accelerating. GREAT FUN THOUGH!

[kibble]

And then the tire fell off, rolled past me, hit a car, and trashed the threads on the end of the axle....oops

LOL! I always wondered if that could happen.

[my_mini_bike]

If you chain is tight, it should come off.
There really is no need for a tensioner, unless ofcourse you dont have enough room for ajustment, and need to take up the slack some other way..
But you do know you can cut out links from your chain if it is to long..?

Pic: i hope you werent running your kart with your chain like that!! That is wayyy to loose.
You want to have it firm with the slightest amount of movment in it

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[ineed2fly]

The wheel thing was actually very funny, it was like the cliche car breaking thing you see on TV, and the wheel keeps going, well I guess it can happen! :P It is tight just to the point where I can take it on and off using the master link, and pulling as hard as I can. I have channels cut in the engine mount, but I can't really get it very tight, and if I take a link out of the chain it's too short and actually pulls the engine down at an angle. And no I didn't run it like that, I tightened it first. I'ts been behaving well, but if it starts to fly off again, I'll put a tensioner on the bottom side. Does anyone know what I can do to fix the threads on my axle? I would however like to get 2 2-piece cogs like 1 40 tooth and one 60 tooth, and a larger length of chain, so I can switch back and forth from torque +acceleration to speed and like no acceleration. My friends and I are joking about drag racing it, I would be crazy slow off the line, but catch up like 1/2 way down. :P I think that over like 300 feet, I could get it up to 35mph, the calculator says it will hit 54 but I can't believe that. Actually more with these bigger tires.....

[kibble]

Get a die of the right size and thread pitch to fix the end of the axle. What size is your axle?

[Kenny_McCormic]

Need pics of axle to see if it can be saved, most of the time you an clean them up with a small file and a half hour.

[jr dragster Tyler]

If you have acces to a machine shop with a CNC machine, do like we did.http://i284.photobucket.com/albums/ll33/juniordragster123/DSC02121.jpg

[I like karts]

OOOOOO SHINY BILLET :arf:

[jr dragster Tyler]

yes sir 7075 1/2 thick aluminum

[sayre315]

you could get a bike tensionor from a 10 speed bike

[I like karts]

1/2"?!?!?!

That seems like overkill to me but...

[ineed2fly]

Ok...so now the chain has been pretty good to me, I think a tensioner would eliminate it all together. However now the problem is if I run the kart for like 15 mins, it doesn't idle, even with the idler screw all the way in. Is it because my clutch is getting hot and the springs loosen up and it engages at a low RPM? But so low that the engine just stalls out?

[jr dragster Tyler]

Your clutch is fried because of a improper gear ratio. To solve the probelem you need a larger number of teeth on the rear axle. And no its not a whole lot of over-kill. The 1/4' steel ones from northern tool bend so if 1/4 steel bends then we whent with 1/2 aluminum because aluminum is softer than steel.

[ineed2fly]

I would agree with the fried clutch thing....cuz now its making weird noises, like a shing then a grinding sound, but like only for a second? IDK, I'm going to kick myself now!!!! STUPID STUPID STUPID!!!! :furious2: Is the clutch totally cooked? Or can I still use it if I get a larger gear on the back? Like 60 tooth?