1983 B&S Flathead (130200 series) Breakdown/Rebuild

[chancer]

Yep just extend that wire to a toggle switch and a wire from the other end of the switch to the block or any ground to kill the engine.

 

[LeeMajors]

Look again...he's talking about the brown electrical wire.

If I see what I think I see..it's a kill switch wire..and used to be hooked to the throttle plate so it made contact when the throttle was all the way closed....you can hook up a switch and hook it to ground for w kill switch.

Thanks man... I was thinking on/off or "kill wire" but had no clue where it went or how, so thank you for clearing that up for me.

Oh hahah..... I see it now....... I was on the phone, just got up and replied.......
It looked like he was refering to the screen.....

Yea I have to agree, now as I look at the pic, it totally looks like I'm pointing at that screen Sorry man. But thx for the reply

Yep just extend that wire to a toggle switch and a wire from the other end of the switch to the block or any ground to kill the engine.

My man... that's a great idea! I can put a little toggle switch up front by the steering wheel or something!? Thanks man!

***Quick Update***
There's been a lot going on so haven't had a ton of time for the build but the engine is basically all back together and ready to go. I'm still waiting on the 3hp flywheel but in the meantime I went ahead and lapped the OEM flywheel and installed it. Also I came across a deal that I simply couldn't pass up so rather than build the frame I'll be purchasing one (maybe 2?) tomorrow morning along with axles, bearings, wheels, slicks+treaded tires, sprockets, brake discs, seats and maybe a few other things I'm forgetting?.. But basically it's the deal of a lifetime and it just makes sense. So I'll be sure to update the thread once I have all items in hand. And hopefully my son and I will be bombing around the yard in the thing before winter!? But we'll see

 

[Mikegtrxu1]

I absolutely love this sort of build, hope to see this working great in the future.

 

[LeeMajors]

I absolutely love this sort of build, hope to see this working great in the future.

Thank you... i appreciate that.

Okay, where to begin?... iv been so sidetracked with the Kart frames and all the parts that I picked up that I haven't done any updates on the motor!? Over all the engines done... it's together, all new seals, Etc.. I need to put the fuel tank on and the exhaust pipe still but everything else is done. The covers painted, the flywheel is on, the magnetron is connected,... everything's basically ready to go! I just gotta put oil and gas in it and start it up! I will get pictures up soon and here's a quick flick of the clutch. I ended up just getting this stock Max torque clutch off of a guy that was interested in the DWT Q Plus wheels that I had. It was my understanding that they only go for like 10 or 15 bucks when they're used? Maybe I'm Wrong?... I Don't Know? But I traded him for wheels and tires that were on them (which were totally bald) for the clutch and a few minor odds and ends (like clevis' and dismounting/recounting some tires just a few other small things) but I thought it was fair.

 

[LeeMajors]

Sry guys idk why those pics are all in odd directions but they're all in the correct orientation in my phone? I'll try to sort it out on my computer when I get home and re-upload them

 

[Poboy kartman]

Sry guys idk why those pics are all in odd directions but they're all in the correct orientation in my phone? I'll try to sort it out on my computer when I get home and re-upload them

It's because you held your phone upright when you took them. It's easiest just to hold your phone sideways with bottom to the right while you take them.

This forum turns pictures in landscape view in that orientation.

 

[LeeMajors]

That's weird that it does that?... but ty for that heads up! Now I know for next time.

 

[LeeMajors]

Hey quick question fellas: Any of you know the size/thread-pitch of exhaust port on these engines? I'm planning on just threading a pipe into the exhaust and adding a baffle or whatnot rather than bolting on the standard way, so I just need to know the size/pitch.

 

[Poboy kartman]

It's pipe thread...IIRC 1/2" pipe.

 

[chancer]

NPT standard usually called out as 3/4" or 1/2". Use typical Threaded Gas pipe nipples for Home Depot etc.

Make sure you add a brace. These like to unthread and also bounce enough to crack the head.

 

[LeeMajors]

Thx for the replies fellas, it wound up being 3/4in NPT.

Now my next issue... She won't stay running. I finally got her started today, and unless the Choke is left about halfway on and about the same amount of throttle it stalls out? Let off either one and it stalls out (ie. throttle off or closed choke). And I've got no clue how it responds under load because I've only started it with the kart on the stand. But just the fact that it's not idling was enough for me to not bother trying to drive it. So far I've checked both the main and idle jets on the side of the carb and both are un-obstructed, as is the needle valve. I've got the needle in the standard 1.5 turns out from lightly seated, and I also checked the gas cap for good ventilation. So now I'm officially stumped...and in need of some suggestions? Thx in advance

 

[LeeMajors]

Also I forgot to mention that this issue is of the utmost importance considering this engine has yet to be broken in and I'm very concerned about the rings seating properly with the constant on/off just trying to get this thing running right. There's a horrible balancing act going on between the choke and throttle just to keep it on at all!? And just as I begin to think I've found the "sweet-spot" she stalls on me (<<<sounds like 1/2 the broads I've dated)!?

 

[Hellion]

Sounds like she's running lean because of some kind of fuel restriction. Is the diaphragm new? Or it could be a vacuum leak.

The mixture screw is set at about 1.25 turns out from gently seated as a starting point. The engine should run off-choke.... Since it doesn't, I suspect your carb is dirty.

For a running or roughly running engine I would advance the speed control for full speed. Then, slowly turn the mixture screw counterclockwise (out), and the engine should run even more roughly. This confirms that it's getting a rich mixture (too much fuel), and this is good. Note the position of the screw.

Now, slowly turn the screw clockwise. The engine note should clean up, and sound healthy. Continuing on, the engine will begin to sound breathy and begin to stumble, this time it's lean. Any further and it'll quit. Note the position of the screw.

Now set the screw slightly to the rich side of halfway between the rich and lean points. Should be real nice and smooth here.

If the engine shows signs of quitting under load (reasonable load), richen the mixture slightly. If it blows black smoke under load, lean it slightly.

 

[LeeMajors]

Sounds like she's running lean because of some kind of fuel restriction. Is the diaphragm new? Or it could be a vacuum leak.

The mixture screw is set at about 1.25 turns out from gently seated as a starting point. The engine should run off-choke.... Since it doesn't, I suspect your carb is dirty.

For a running or roughly running engine I would advance the speed control for full speed. Then, slowly turn the mixture screw counterclockwise (out), and the engine should run even more roughly. This confirms that it's getting a rich mixture (too much fuel), and this is good. Note the position of the screw.

Now, slowly turn the screw clockwise. The engine note should clean up, and sound healthy. Continuing on, the engine will begin to sound breathy and begin to stumble, this time it's lean. Any further and it'll quit. Note the position of the screw.

Now set the screw slightly to the rich side of halfway between the rich and lean points. Should be real nice and smooth here.

If the engine shows signs of quitting under load (reasonable load), richen the mixture slightly. If it blows black smoke under load, lean it slightly.

Yes, it a new diaphram. And I'll get some crab cleaner and chk for vacuum leaks and get back. thx hellion

 

[LeeMajors]

Okay fellas, I really need some assistance here. So, due to all the mods made on the engine it's "breathing" quite a bit more than a standard Briggs 5hp would and as it turns out I simply wasn't getting enough fuel into the mixture. I went to a local (semi-local) kart shop and explained all of my current mods, along with the issues I've been having, and they drilled a few jets out for me. So I'm up to the largest one (.039in) they gave me and I finally got it running w/choke-off! BUT I still can't get it idling properly!? As soon as I let the throttle go ("speed" screw/butterfly screw turned almost all the way in) it leans out and stalls. Also, if I turn the speed-screw all the way in it idles but at such a high rpm that the clutch engages!? And if I hit the brake?.... it stalls. So... what now? Normally I'd just assume turning the mixture screw out would fix this but I've learned (via all my recent tinkering with this darn thing) that you can only back that screw out so much before it begins to affect the carbs ability to pull fuel from the bowl. Or if it is still pulling fuel, the needle is too far out of the jet to properly atomize it? Either way I think I need an even larger jet? But Idk? So I need some feedback...plz? If anyone's familiar with this plz comment... my patience with this thing is waning.

 

[LeeMajors]

Ok so i may have jumped the gun on my last comment. The engines running and it even idles... but in order for it to idle I need the choke ever so slightly closed and all the way open when on the throttle. Funny thing is im pretty sure that's how these "slider"carbs are supposed to work anyway? All the ones I've seen have a armature that connects the throttle linkage to the choke, but mine doesn't have this? Anyway, I'm still working on sorting all this out. But it does run like a raped ape! So I. Stoked for that. Once I get it all sorted I'll UL the rest of the pics from where I left off in the build process, and I'll get some vids of it running driving etc.. In the meantime here's a pic of the kart as it sits now.

 

[Hellion]

Glad to hear you got it semi-sorted out. You might need to richen the mixture a bit--the engine should like it.

Did you break it in properly yet and change the oil?

There's several guides around the interwebz for what constitutes a proper break-in procedure...

 

[chancer]

I like it. Cant wait for more pics!

 

[LeeMajors]

Glad to hear you got it semi-sorted out. You might need to richen the mixture a bit--the engine should like it.

Did you break it in properly yet and change the oil?

There's several guides around the interwebz for what constitutes a proper break-in procedure...

I hear that brother cause it wants it rich in order for it to idle but lean for it to run smoother at high rpm!? So I'm still fiddling with the different jets and the mixture screw. But it's definitely getting better!

This I have not done yet. Although I have been reading all the different break-in guides and have a pretty good idea of how I'd like to do it. I also feel like part of my trouble is the fact that it isn't completely broken in? Because it seems as though the more it runs with no changes the better it's getting, but of course this could all be in my head? lol! Seriously though it's MUCH easier to start now than it was, idk, 3days ago. The problem I've been having in terms of a solid break-in, is that I've yet to find that sweet spot in the mixture/throttle where I can leave it on the stand, or whatnot, and let it run for 45mins to an hour. And if I set it at half throttle and do it it will jump the stand or vibrate its way across the garage!? lol! So to answer your question my directly; No, I haven't broken it in and changed the oil yet. But I am working on it

Oh! On a side note I have taken it on 2 very small rides and it's quick! Definitely no drift-missile though The torque's just not there... there could be a bunch of variable at play in that though, most notably the fact that the rings aren't completely seated yet.

I like it. Cant wait for more pics!

Thx Chancer! I didn't get into aesthetics AT ALL on this, which is usually my "thing". This was much more of a rush job (the Kart itself I mean) just to get the engine on it and cruising around; more of a function-over-form type job, you know? I think the Frankenstein seat I made really speaks to that fact?... I mean I just left it raw fiberglass and resin bro!? Lol! Totally one of those NFG moments in the build. I'll definitely get more pics up soon though, and I may wind up doing a build log on the kart itself cause I did take a lot of pics in the process..? But I might save it for the rebuild when I really aim to make it all pretty and stuff? We'll see...? Did you happen to peep the custom pedals I made from scraps laying around in my garage? The accelerator pedal is made from a piece of an old strut tower/brace bar thing + exhaust hangers and the brake pedal is (iirc?) an old kick-starter from a dirt bike that I came across during that trip I made to the U-Pull-It way back in the beginning of this build! lol! Just straight up garbage I had laying around! I had to hack and weld the kick starter about 3 times to get it right and then I welded it to an old ARP head-stud, so I could mount it through the frame.

Anyway fellas, here's what I figured out today... Slider choke carbs, work MUCH better with a slider. So after much thought and internal debate, and simply reaching an uncomfortable level of frustration, I decided that the only way I'd ever get this thing running right was to connect the choke to the throttle. So I bust out the drill, found a piece of metal just the right length, made a few bends and a couple holes, and VIOLA! It idles! (I'll post a few pics from my phone in a min) So yea.... slider chokes work better when connected! lol! I do have to say that, in my particular instance, the choke lever didn't have a hole in it or any other way of connecting, like I've seen on most of these slider style carbs, so I never thought it was supposed to BE connected? And maybe in reality it's NOT supposed to be connected? But for all intensive purposes, in my case, it's what works... So I'm rockin it.

 

[LeeMajors]

Here some pics of what I added to the carb. You'll have to go back a few pages to see what it looked like before but all I did was drill a small hole in the throttle linkage, another small hole in the choke lever, connecred via small rod and a screw with a flat piece of metal to hold the rod in place... as you'll see in the pics. I hope this makes sense? All this does is close the choke when off throttle and open it at WOT. With this "linkage" in place the choke position is now directly proportionate to throttle position and for what ever reason that WORKS with my build, so I'll take it.