Boy Scout kart build - dubbed "The Hot Rod"

[Doc Sprocket]

DO NOT remove the oil injector. It was put there for a reason. its bad to remove it and mix your own gas. plus I don't think jetting has a thing to to with it. i have seen so many other snow mobile engine swaps and have never heard of anyone having to re-jet.

Where'd you get this? From what I understand, this is done quite frequently! Think about it- An oil injector system can fail at a bad time (is there ever a good time to run lube-less), YET-

If you're mixing the right ratio, the engine ALWAYS gets lubed!

Case in point- A friend of mine recently got wayyy too close to being stranded out on the lake because the oil injection line on his outboard motor popped off while cruising at speed. He's still not sure if there's damage to the engine. Do you suppose this could have been avoided by mixing his fuel and oil, having bypassed the injection system? Absolutely!

As far as I'm concerned, oil-injected 2 strokes were created for people too lazy and/or stupid to be able to handle the simple task of mixing batches of fuel and oil prior to pouring it in...

 

[Redline-Go-Kart]

In fact half of my toys are two stroke

 

[redsox985]

TS makes a great point. There is no good reason to have an oil injector. It's simply an easier way to kill your engine.

 

[Doc Sprocket]

I try.

 

[Garified]

Toy Story couldn't have said it better.


I trashed the oil injection on my jet-ski before I even bothered running it. Got rid of that, removed the oil/gas tank, cleaned both out, mixed my fuel with a 30:1 fuel/oil ratio, never had a problem with it.

I now use the oil tank as a reserve gas tank!

Oil injection - Not required if you mix your own fuel and oil.

 

[B man]

I have heard it said because the oil injector sends oil to important places that it cant get by itself.

like on Bigheads thread about fixing that dirt bike for glb7. the crank case bearing was out because the oil injector wasn't used. since they mixed it themselves it didn't get proper lubrication on the bearing.


hears what big said.

I am thinking when you guys starting mixing your own gas and not using the oil enjection. Then the crank bearing did not get no oil. Another reason never to unhook the oil enjection system.

 

[Bugzuki]

If the injection system put oil on the bearings, wouldn't the crank case get full of oil eventually?

I personally have never owned a 2 stroke before, so I need as much help as I can get.

 

[DaiSan76]

If the injection system put oil on the bearings, wouldn't the crank case get full of oil eventually?

I personally have never owned a 2 stroke before, so I need as much help as I can get.

It works like this, the injector would spray an oil mist either into the crankcase, or in the intake where you see the blue coming in.
I did some googling and found reference to a leaking transmission seal leaking gear oil into the crankcase, which could cause white smoke.

 

[DCProductions]

I don't think an oil injection system could get oil into important places any better than a saturation of 2 stroke gas. In fact, if it was injecting oil into places normally unreachable, that oil would have no way to reach the gas, leaving it poorly lubricated. Saturation is classically the best way to lubricate anything.

If the injection system is on the carb (I don't do 2 stroke so no experience here) than there is no need to have it. There is nothing in the carb that needs specific lubrication. If the injection system is on the crankcase than there could possibly be some sort of specific lubrication system, though, as I said earlier, I can't see that being more lubricating than saturation of premixed gas.

Hope this helps?

 

[Bugzuki]

As far as I can tell the oil injection is into the intake runners after they split to each cylinder. I did not notice anything going into the crankcase, but the oil injector is mounted to the side of the case, so there could be something I can't see. But, probably not.

There is no transmission attached to the engine, so no oil leaking from there.

Maybe the oil injector is just over zealous and is pumping too much oil in.

Oh yea, thanks for the pictures Dan. I still think it is amazing that a 2 stroke can work.

Another thing I noticed is that when running there is a fuel mist coming out of the carb. Is it supposed to do that?

 

[Bugzuki]

Reconfigured rear suspension

Ok, So I was irritated by the rear suspension and did some work on it. Took me a couple days. Now, I have it mostly done and it functions. It is very stiff, but that is better then complete droop all the time.

Here are some Pictures of the pushrod system I made.

 

[DCProductions]

Me gusta pushrods. You could make that adjustable if you made some more tabs on the underside of the pivoting piece; though it sounds like you're just happy to be done with it.

 

[machinist@large]

Very nice!! I'm definitely going to keep your build in mind if/when I decide to build something like it. Especially the thought of just starting with a sled engine from the start. Another thought was trying to find the dive train from an old 3 cylinder Geo Metro

Cudo's on a great build. And Thanks to all the people who posted ideas; good food for thought.

 

[robotmickey]

I think thats an awesome way to solve your problem. I think though that your pushrods may buckle if you hit it wrong, I think that if you weld some square pipe to the out sides of it, it would make it stronger. I think it's a real good design.

 

[gfigs911]

perhaps an air filter on that engine??? I know most of the older sled engines dont use air filters, and its usually not as dusty in winter when the sleds are out and about...but during summer use maybe it would be a good idea?? just an idea...I found a cheapo air filter at my local hardware store and luckily it was the same diameter as the carb intake...

 

[Bugzuki]

Thanks guys. I had thought about the push rod bending, and have been thinking about stiffening ideas. The square tube is a possibility, or welding on some flat bar.

Yep, I will put an air filter on it. The one I had for it seems to restrict the air flow to hardly an idle. I need to find another one.

Well, I did some work on the drive today. I realized that I was thinking backwards on the gear ratio. So, I took off the 43 tooth drive sproke I had and put on a 12 tooth. Then I put some 1/2 spacers under the engine.

IT NOW MOVES ON ITS OWN. I am soo excited. I should take another video.

Thanks for all your help guys.

Now, I just have some fine tuning to do. Like one of the axle shafts is a little too long so it binds a little. And some wiring stuff. And finish connecting the reverse lever. Oh, and the smoking and idle issue.

Sweet.

 

[Sentrek]

As far as I can tell the oil injection is into the intake runners after they split to each cylinder. I did not notice anything going into the crankcase, but the oil injector is mounted to the side of the case, so there could be something I can't see. But, probably not.

There is no transmission attached to the engine, so no oil leaking from there.

Maybe the oil injector is just over zealous and is pumping too much oil in.

Oh yea, thanks for the pictures Dan. I still think it is amazing that a 2 stroke can work.


I am no expert on sled motors but I have owned many two stroke dirt bikes. The crankcase should have it's own oil supply and should use regular motor oil ( per manufactures recommended specs) the two stroke oil that goes in the oil injector is meant to lubricate the cylinder only and mostly burns up when the motor fires, this is why two strokes smoke as much they do. I would do as many have suggested and ditch the injector and manually mix the oil/gas.

 

[steve01]

Maybe i can help you a little on your motor. All the white smoke is probably oil. you can adjust your oil pump by holding your throttle wide open and lining up the marks. One is on the lever the other is on the pump body.
Myself i have never had a oil pump go bad. I do inspect my lines and look for chaffing and i keep clamps on them.
If you want to eliminate the oil pump just take it off and make a blocking plate to cover the hole and plug the holes in the intake where the oil lines went.
As far as re jetting goes a 2 stroke that is set to run at 20 will be to rich at 70 you need to re jet every 15 degree or so. Keep your plugs looking the color of coffee with 2 creams. The intake is also fussy on 2 strokes. when you get up and running will be the time to start playing with the jets. Keep them tuned in and you will always be in front of the pack!!!!

 

[Bugzuki]

I am no expert on sled motors but I have owned many two stroke dirt bikes. The crankcase should have it's own oil supply and should use regular motor oil ( per manufactures recommended specs) the two stroke oil that goes in the oil injector is meant to lubricate the cylinder only and mostly burns up when the motor fires, this is why two strokes smoke as much they do. I would do as many have suggested and ditch the injector and manually mix the oil/gas.

Sled motors don't have a transmission in them, so there is not really much to the crankcase accept a bottom of the engine. There is no dipstick or fill tube. At least this one. I will take a look again just incase I missed it.

Maybe i can help you a little on your motor. All the white smoke is probably oil. you can adjust your oil pump by holding your throttle wide open and lining up the marks. One is on the lever the other is on the pump body.
Myself i have never had a oil pump go bad. I do inspect my lines and look for chaffing and i keep clamps on them.
If you want to eliminate the oil pump just take it off and make a blocking plate to cover the hole and plug the holes in the intake where the oil lines went.
As far as re jetting goes a 2 stroke that is set to run at 20 will be to rich at 70 you need to re jet every 15 degree or so. Keep your plugs looking the color of coffee with 2 creams. The intake is also fussy on 2 strokes. when you get up and running will be the time to start playing with the jets. Keep them tuned in and you will always be in front of the pack!!!!

Thanks for the info on adjusting the pump. I will look at that tonight. It seems to have settled down on the smoke a little bit. I will put up a video of it driving later.

Thanks for the jetting information. How do I go about getting new jets? So, I should get one for 75 degrees and one for 90 degrees? Are they hard to change? I have a manual that talks about a bunch of Arctic Cat sleds, so I will see what it says about jetting.

 

[steve01]

You can pick jets up at any snowmobile or motorcycle shop. the carb you have should have a bolt on the bottom of the float bowl. Just remove the bolt and you can see the jet. It will be made of brass and should be about 6mm. put a socket on it and it should turn out. It will have a number on it. The parts guy can help with size you need.