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/diy/ - Do It Yourself

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464934 No.464934 [Reply] [Original]

Ok, this fall I picked up an older Briggs and Stratton 4-stroke, 266cc rototiller with the intent of a minibike, go-kart etc. in mind. It'll be a simple, probably underthought job, but that's not what this thread is about. I have a few questions, rather, for our engine nuts, as internal combustion us not my strongest point.

One: when I first started the engine, it ran rich and flooded, but after a short wait I was able to start it, peak it, and it ran with no issues throughout the full range of throttle. When I cut it, however, it screeched with a terrifying, soul-eating, ear destroying loudness. I was able to restart the engine without trouble several more times, but not without the screeching. The neighbors actually came to see what the fuck was up.

Two: I figured that while I was solving the screeching mystery, I would begin tuning up the engine. I washed the foam element in the air filter, and set it out on my deck to dry. When I came back out, the neighbor's cat had torn that bitch to shreds. Parts for these engines are NOT hard to find, seeing as from 1970 to 90 they pretty much were painted in different colors, but I'm cheap as hell and, on top of that, I'd like to know if there's just some way to create my own air filter. I have the original case to work with. It seems to me that there might either be an easy way to create a paper element, or that a replacement might be easy to find.

Tl;dr, My engine is screeching like fucking Mariah Carey, and I also wanna make a new air filter for it.

Pic related, it's pretty much the engine.

>> No.464945

Anyone?

>> No.464946

those filters are probably like $5. just buy it.

>> No.464947

>>464946

But... the diy...

>> No.464949
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464949

Could be a dry starter clutch bearing. Put some grease in the centre hole or if you can't get it in take it off and grease the shaft then reinstall. Could also be a slipping belt sound if that is still attached.

>> No.464950

>>464949

Ok, thanks. I'll give it a try.

>> No.464951

Also worth a look:

http://bgsengineclinic.com/downloads/index.php?fetchfile=Briggs_1919_to_1981_AntiqueEngine_Manual.pdf

>> No.464954

>>464951

Sweet

>> No.464965
File: 27 KB, 475x316, 33584_58039.jpg [View same] [iqdb] [saucenao] [google]
464965

>>464934
I have found old foam air filters often fall apart once you wash them anyway so it may not have only been the cat.

The model number should be on the fan housing somewhere stamped into it. I have an old cast iron block one form the 70s and it would be luck to have 100 hours use on it. The air filter perished just sitting in the shed. Proved a bit hard to find one but it was ordered in eventually.

>> No.465034

when i was little, I had a go-kart with a 5HP engine on it. it threw a rod, and I didn't yet know how to rebuild an engine, so I "borrowed" one from my dad's rototiller, just like the one in OP. sadly the rototiller engine was only 2HP, and barely moved the cart. all that work, and my dad got pissed at me for nothin. I put the tiller back together, and then ordered a new connecting rod for my engine.

>> No.465049

The screeching sound is probably a slipping belt, tighten or replace that shit.

I have an old 2-stroke 250cc dirtbike. A few years ago I was trying to get it running again and I saw the foam filter had disintigrated into the intake (Filter slipped over a metal cage).

I just slipped a few old but clean socks over the metal cage and zip-tied it. Must not be too restrictive, still hauls ass on the trails and isn't running lean.

>> No.465051

>>465049

*Meant to say rich instead of lean

>> No.465229

>>465049
You could also try belt dressing.

>> No.465251

>>465034
Had the exact opposite situation.
3.5 HP cart, found a dead roto tiller with a good 8 HP engine.

I shredded the cheap hard rubber wheels in a day.

>> No.465253

Screeching might be the pull starter.
On a old beat up go cart I had the rope would slowly creep out and the starter would partially engage and when that happened it gives a ungodly scream that can be heard by the entire neighborhood.
Your starter rope is hanging out a little so I would check that.

>> No.465726
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465726

Relevant to your project is a Go-Kart bike I finished last year.
Budget was under $1000, although I did already have the frame on-hand.

Seat cushion foam works okay as a replacement filter.

>> No.465727

how about a sponge?

>> No.466152

Op here.

>>464949
>>465253
I removed the starter and re oiled the clutch, which, indeed, was very dry. Like, bone dry. I replaced it and intended to start the engine today, but discovered that there's at least a little water sitting in the bottom of the tank... gonna drain it and try again tomorrow. If the chord is a problem, I may permanently unbolt the starter and hold it on to start (this seems to be an accepted method, other than replacing the chord.)

Also, the sock thing is going to happen.

>>465049
I also suspected the belt, although the problem is sort of the inverse. The rotor clutch is made up of a standard V-belt, fitted with a nifty mechanism that tightens the belt down when you want to engage the rotors. The belt has a tendency to stick when you engage and then pull the clutch out, which, I half suspect, is at least contributing to the screeching, as it stays tight in a way as the engine is spinning apart from it.

Either way, I'll be buying a new belt, along with many other things. Just about every disposable part of the engine seems to have teleported out of the 70's, and nasty black oil is caked all over the mud guard ("I guess I should change the oil... how do I work this shit... here we go, oil plug. HELL YEA, REAL MAN")

>> No.466198

>>466152

heh, fuck u lawn.

and what the hell is with changing oil on lawn mowers? I have some pos brigs and straton mower and the service manual literally says flip the thing over to drain the oil out of the dip stick hole. that seemed full retard so I just used a hand pump.

>> No.466286

>>465726
I fuckin lurv that little pos every time you post it. didnt you say you originally wanted to make it electric? what was the hang up on that? also what pitbike frame is it?

>> No.466303

>>466198
Most have a drain plug underneath but flipping them is often easier. A pump sounds handy though.

>>466152
What I do to dewater gas tanks is fill with e85, shake it about to mix the water then drain. Then fill with regular gas.

You may find water in the carburettor bowl also.

>> No.466653

Alright. I pumped the tank and filled it back up, reattached the clutch, set the filter up with an old pair of underwear (yeaaa!) and let 'er rip. Ran extremely lean, even after several more pairs of shorts, running very fast and then stalling every time. The screech was gone (mostly.) At least, it was no longer a banshee wail. This leads me to believe that the problem really is in the clutch, so I'm gonna take the complex back off the front and really saturate it with oil.

The bolts are all rusted to high hell, and disassembling anything is proving to be a real pain in the ass. I can usually work though the rust, but buying a new set is probably warranted.

Also, that is one kick-ass bike, sir.

>> No.466663
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466663

>>466286
>didnt you say you originally wanted to make it electric? what was the hang up on that?
I fried three brushed motors before deciding I didn't want to burn more money on a brushless outrunner setup. Here's a pic of it prior to this reincarnation.
>>also what pitbike frame is it?
X-motos XB-35