A few questions...

[Optiskate]

I suppose I should start off with a little back story. My friend had a go kart that sat in the garage for years. Awhile back (years and years ago) we decide to bust it out, setup a course, and try to beat each others times around said course. We got crazy with it and centered the steering wheel (making it a 1 seater but we kept the bench seat) and threw on what looks to be a TAV2 torque converter. BTW The engine is a B&S 5hp Fun Power. My friend ended up breaking the chain and lacked funding to fix it, so it sat, and we ended up forgetting about it after it got buried in the garage.

Fast forward 4 or 5 years. My friends parents wanted the go kart out of their garage and my friend offered it up to me. I had so much fun with it that I couldn't pass it up. It needed new oil, gas, and the throttle linkage was sketchy at best as it liked to stick open. Minor things to fix. So I started looking for the throttle linkage online and one thing lead to another. I ended up with a pile of go fast parts for it. Yes, I know, its a dual bushing aluminum block. I did my home work on it. I know it wont last forever and I didn't go horribly extreme on the parts. I just wanted something to mess around with and to have some fun with on occasion. Its one of my hobbies to throw money at stuff I have laying around even if its a lost cause.

Either way, I have a 94SS cam, new head, ARC billet fly wheel, ARC billet connecting rod, billet lifters, new exhaust and intake springs, air filter adapter, K&N filter, 3 stage exhaust & race muffler, a set of fly wheel key dealies, a complete felpro gasket set, and so many other small things that I really cant remember everything right now.

Now on to my questions. I've got the engine all stripped down and the only things left in it are the crank, cam, and valve train. This is more than likely a very stupid question especially since I could hit the search button. How in the heck do I get the valve springs, lifters, and valves out. I'm assuming I need a special tool.

Also, I regret it now, but funding did not allow me to just buy a raptor carb. So I bought the filter adapter and filter. Hind sight its 20/20 I guess. I highly doubt that my carb will provide enough fuel. The engine actually isn't the original engine. My friend burned the original one up and they ended up getting a new one. For some reason I remember seeing a date stamped some where on the engine saying 2001 was the manufacture date for something. Which makes sense because they replaced the engine 2001-2002ish. I don't know if there are any differences between older and newer fun power carbs. Either way, is there any hope for this carb? I remember reading that the jets might be cast into the carb. I haven't disassembled it to find out for sure. I have access to a machine shop and pretty much any tool to get what ever job I need done. Machining cast in jets is an option. Does any one know of any one doing such a thing if the jets are in fact cast into the carb? Also are there any other parts that might help the carb if machining is an option. I'm really hoping that I can change the jets or at least machine them as kid #2 will be here very shortly and money for a new carb just isn't in the budget.

This is really my first flat head engine build. I've got some pretty extensive experience working on Jeeps. I can tear down axles, trannys, suspension, t-cases, and the like, but this is the first time I've got this deep into a small engine.

Any way, thanks for reading my novel.

 

[redsox985]

Please tell me you have it ungoverned.

 

[slideways]

That carb will be fine. Whether its a Raptor carb or not the concept/build is the same. Its when you get totally nasty with the motor that you need a Tilly or something and have to ditch the on tank setup. You'll be probably in the 8-10hp range with basically just the cam and whatever work you do to the carb as your power adders. Billet rod and lifters don't add power but rather reliability. I don't know what flywheel key you got but you'll probably benefit from a 6 or 8 degree advance. Mill the head down a little bit and run premium fuel.

BTW: I hate flatheads.. they are a waste of time to me but the concept of all engines is the same. More air/fuel in.. more power out. As far as getting the springs out.. you want a tool like a fork. Push down on the spring while holding the valve in place to take the tension off of the keeper. Once you get that to pop off the valve will just fall out and you can slide the springs out through the breather area.

 

[Optiskate]

Please tell me you have it ungoverned.

Yeah I pulled the governor out. Funny story actually and another question. It looked as if the flap on the inside end was either pressed on or screwed on, but it wasn't. It came off with a hammer and a punch. The flap actually just broke in half and fell off the shaft leaving the shaft intact. Now that the shaft is back in place it has about 1/16" of play with the clip and washer on the outside. I was iffy about putting any sort of silicon on it. My logic being that if it didn't have any before and it didn't leak, then why should it leak with the shaft in place. What do people normally do to take up that little bit of play in the shaft?

I was thinking about putting a washer on the inside end of it to take up the play in the shaft. That way if it did leak I could put silicone around the shaft and have it sandwiched between washers on both ends of the shaft. I'd rather not use silicone any where where it could get inside the engine though.

 

[sideways]

Nice story mate .

To get the valves out find a big screwdriver and place it between the valve spring retaining ring and the engine block and leaver it so its trying to push the valve open. Hold the valve closed with your other hand and lever it, now, either you with have 2 little retainers that go together to make the shape of a cone or a larger hole in the the retainer which allow it to slide off the valve stem (I hope that makes sense). Remove the 2 little retainers or slide the retainer up and through, make sure you don't loose that retainers! Their **** easy to loose!

As for the carb, you would be better off with one from a small motorbike, the Briggs carby you have now is in my opinion, one of the crappest carbies ever made. If your going to keep it the but a new diaphragm in it, it will work much better.

I hope this helps

Thanks

Hayden

 

[Optiskate]

That carb will be fine. Whether its a Raptor carb or not the concept/build is the same. Its when you get totally nasty with the motor that you need a Tilly or something and have to ditch the on tank setup. You'll be probably in the 8-10hp range with basically just the cam and whatever work you do to the carb as your power adders. Billet rod and lifters don't add power but rather reliability. I don't know what flywheel key you got but you'll probably benefit from a 6 or 8 degree advance. Mill the head down a little bit and run premium fuel.

BTW: I hate flatheads.. they are a waste of time to me but the concept of all engines is the same. More air/fuel in.. more power out. As far as getting the springs out.. you want a tool like a fork. Push down on the spring while holding the valve in place to take the tension off of the keeper. Once you get that to pop off the valve will just fall out and you can slide the springs out through the breather area.

Thanks man. I actually have a whole assortment of fly wheel keys and a head off a raptor that has already been milled. As far as the carb goes. I won't know if I can jet it or if I'll have to mill it out until I rip into it too. Like I said, this whole thing is new to me. Do you know if something like this will work with a fun power carb? http://www.geckermotorsports.com/shop/details.asp?prodid=MTS-0103&cat=520&path=511,520

If it will I'll pick it up because anything will help.

Also, this is going to sound stupid, but what way does the oil dipper on the rod need to face with the ARC rod? Toward the cam or away from the cam? Toward would be my guess, but I'm not 100% sure. I should probably figure it out before attempting to reassemble it.

 

[Optiskate]

Nice story mate .

To get the valves out find a big screwdriver and place it between the valve spring retaining ring and the engine block and leaver it so its trying to push the valve open. Hold the valve closed with your other hand and lever it, now, either you with have 2 little retainers that go together to make the shape of a cone or a larger hole in the the retainer which allow it to slide off the valve stem (I hope that makes sense). Remove the 2 little retainers or slide the retainer up and through, make sure you don't loose that retainers! Their **** easy to loose!

As for the carb, you would be better off with one from a small motorbike, the Briggs carby you have now is in my opinion, one of the crappest carbies ever made. If your going to keep it the but a new diaphragm in it, it will work much better.

I hope this helps

Thanks

Hayden

What in your opinion makes the B&S carbs so crappy. Where are their short comings? Would a bike carb be an on tank deal like the stock unit? Actually, do you have any links to swaps?

Thanks for the advice on the removing the springs and valves.

And one last thing. Would hardened spring retainers be worth the investment with a more mild build like mine?

 

[sideways]

Thanks man. I actually have a whole assortment of fly wheel keys and a head off a raptor that has already been milled. As far as the carb goes. I won't know if I can jet it or if I'll have to mill it out until I rip into it too. Like I said, this whole thing is new to me. Do you know if something like this will work with a fun power carb? http://www.geckermotorsports.com/shop/details.asp?prodid=MTS-0103&cat=520&path=511,520

If it will I'll pick it up because anything will help.

Also, this is going to sound stupid, but what way does the oil dipper on the rod need to face with the ARC rod? Toward the cam or away from the cam? Toward would be my guess, but I'm not 100% sure. I should probably figure it out before attempting to reassemble it.

That throttle shaft is a huge rip off, it's just a standard one with the back edge filed down, it wont really give you any more power, the throttle isn't the most restrictive part of the inlet. Certainly not worth $18, you could make it yourself for $0 and about 10 minutes of your time.

There should be a notch or something on the rod so you can only mount the big end on one way, anyway, the point should face towards the the cam.

What in your opinion makes the B&S carbs so crappy. Where are their short comings? Would a bike carb be an on tank deal like the stock unit? Actually, do you have any links to swaps?

Thanks for the advice on the removing the springs and valves.

And one last thing. Would hardened spring retainers be worth the investment with a more mild build like mine?

Briggs and Stratton use that carb specifically because it's cheap to make. It has a diaphragm in it which after a few years goes hard and makes the engine **** near impossible to start, the design of the carb certainly doesn't lend itself to performance. So what are it's advantages? It costs basically nothing to make and it's resistant to stale fuel. That's it really.

There are no modern carb on tank style bike carbies (for good reason), you would need to get a separate fuel tank and mount it. I'm sure there's adapters to mount Mikuni carbs on a Briggs somewhere on the internet, just google it. I've never bought an adapter like that before, I make my own ones, so I don't have any likes to that kind of stuff.

As for hardened spring retainers, not really necessary on your engine. I cant really see any reason why one would break. Even if it did then I cant see it doing much damage to your engine.

Thanks

Hayden

 

[Optiskate]

That throttle shaft is a huge rip off, it's just a standard one with the back edge filed down, it wont really give you any more power, the throttle isn't the most restrictive part of the inlet. Certainly not worth $18, you could make it yourself for $0 and about 10 minutes of your time.

There should be a notch or something on the rod so you can only mount the big end on one way, anyway, the point should face towards the the cam.



Briggs and Stratton use that carb specifically because it's cheap to make. It has a diaphragm in it which after a few years goes hard and makes the engine **** near impossible to start, the design of the carb certainly doesn't lend itself to performance. So what are it's advantages? It costs basically nothing to make and it's resistant to stale fuel. That's it really.

There are no modern carb on tank style bike carbies (for good reason), you would need to get a separate fuel tank and mount it. I'm sure there's adapters to mount Mikuni carbs on a Briggs somewhere on the internet, just google it. I've never bought an adapter like that before, I make my own ones, so I don't have any likes to that kind of stuff.

As for hardened spring retainers, not really necessary on your engine. I cant really see any reason why one would break. Even if it did then I cant see it doing much damage to your engine.

Thanks

Hayden

Thats good to know. I cant be wasting too much more money. I'll just file down my throttle shaft.

So as far as my carb goes, my best and most cheap option sounds like it would be to file my throttle shaft, drill out my jets slowly until I get the fuel I need, replace the diaphram, and just all around rebuild the **** thing. It actually shouldn't need rebuilding as this particular engine only had maybe 15-30 hours of run time max, but just to be safe. If there's anything else carb wise you can think of that I should try to get more performance out of it?

I may get hardened retainers just for peace of mind.

As far as the orientation of the ARC rod, I didn't see any notches or anything. From what your saying I'm taking in that the hole in the oil dipper should be facing the cam.

So essentially it sounds like I have some porting to do and a little bit of other minor cleaning up and then its on to reassembling the block and then I'll be tackling the carb jetting as needed.

I cant wait to have this thing running... urgh... I guess I still have to tackle some chassis stuff, but that stuff is simple.

Thanks again man.

 

[sideways]

Thats good to know. I cant be wasting too much more money. I'll just file down my throttle shaft.

So as far as my carb goes, my best and most cheap option sounds like it would be to file my throttle shaft, drill out my jets slowly until I get the fuel I need, replace the diaphram, and just all around rebuild the **** thing. It actually shouldn't need rebuilding as this particular engine only had maybe 15-30 hours of run time max, but just to be safe. If there's anything else carb wise you can think of that I should try to get more performance out of it?

I may get hardened retainers just for peace of mind.

As far as the orientation of the ARC rod, I didn't see any notches or anything. From what your saying I'm taking in that the hole in the oil dipper should be facing the cam.

So essentially it sounds like I have some porting to do and a little bit of other minor cleaning up and then its on to reassembling the block and then I'll be tackling the carb jetting as needed.

I cant wait to have this thing running... urgh... I guess I still have to tackle some chassis stuff, but that stuff is simple.

Thanks again man.

Your carby should have replaceable jets, buy a whole bunch of jets for it, their much cheaper than micro drill bits, drilling the jets isn't a very accurate way of doing it anyway. As for the diaphragm, they go hard when you don't use them so yeah. Was the engine difficult to start before you pulled it apart?

The big end cap should be positioned so that the dipper curves toward the cam side of the engine.

Can't wait to see it running mate

Thanks

Hayden

 

[Optiskate]

Your carby should have replaceable jets, buy a whole bunch of jets for it, their much cheaper than micro drill bits, drilling the jets isn't a very accurate way of doing it anyway. As for the diaphragm, they go hard when you don't use them so yeah. Was the engine difficult to start before you pulled it apart?

The big end cap should be positioned so that the dipper curves toward the cam side of the engine.

Can't wait to see it running mate

Thanks

Hayden

I think it might be the pulsa jet carb or what ever it is with the jets that aren't replaceable, but I wont know until I tear into it I guess. If they are replaceable, then I'll just buy a set of jets and go to town. If they aren't, then not to worry. I have access to a mill. Not a cheapo drill press, hand held drill, or anything like that, but an actual high end gigantic mill that you can do some extremely precise cutting on. My dad does a lot of machining for people and I have access almost everything I need to build what ever I want. I just have to drive over to his place and the keys to the shop are on my key chain. Just the a couple weeks back we machined a pilot bearing within 3 ten ten-thousands of an inch of 1" and then got it to a perfect 1". Needless to say the installer of said pilot bearing said hes never seen one fit so well. So if push comes to shove, accuracy is no issue since we can make factory like or better parts with a little time to properly setup the equipment.

I didn't even try to start the engine. The gas in the because the gas was most definitely bad. It had been sitting for about 4 years. So to be safe I'll just replace the diaphragm. I could have put good gas in it and some new oil and it more than likely would have started up. I just got in a hurry to rip the engine down since I'm generally slow and methodical about my projects and I want to get this thing done before it gets cold. Its easier to trouble shoot and fine tune things when you aren't miserably cold and/or driving on snow and ice. I do have a neat idea for ice tires though for when the neighborhood does freeze over. Not to mention I also need time to do some chassis mods, fix a few things on the chassis, and paint it (im thinking multicam). So I'm quickly running out of time.

I'll definitely post it up when I'm done for you guys to check out.