Engine schreeching sound

[wloch248]

Been lurking for a while and finally need help. Background: traded a 2 stage snowblower for a cart project. Came with 2 B&S 5 horse engines. Original engine had a intake valve stuck open because the prev owner left it uncovered outside and got water in it. He then bought another B&S 5hp off a minibike,it ran until he decided he needed to switch gas tank brackets and put holes in the gas tanks. I bought yet another B&S 5hp from a generator (didn't know they have tapered shafts and can't use them on carts until I did research AFTER buying). I transferred the air cleaner and tank from the tapered shaft engine to the one he had got from the minibike. Fired it up and runs fine.

I then put it on my cart hooked everything up, did a LOT of other work. and decided to fire it up and take it for a spin. I was revving it in the garage to make sure everything was ok BEFORE I got on and the engine starts to make this screeching sound and stops. I freak out thinking I just burned up the cylinder. I take the plug out and it is fine, I turn it over without the plug in and it turns over smoothly. I put the plug back in and fire it up. It idles fine same thing happens when I rev it up,screeching, then I shut it off before it can die. I still think I an messing up the cylinder so I put a small amt of synthetic oil down the plug hole and fire it up again after letting it sit for a min. It starts, idles, blows a little smoke out from the oil I just put in, screeches on acceleration and dies. It still turns over, Yes it does have oil in it (fresh oil change), only engine mods are K&N type air filter, custom exhaust (dirt bike silencer welded to stock flange), and just the governor gear was removed (before I got it and the outside lever is in place) I had previously taken the side cover off to confirm this and everything looked good, no parts from the governor setup were touching anything and everything in there looked very clean. This is not a clutch issue, it is brand new and engages with an increase in rpm and I know enough that it is some sort of internal engine noise.

Any advice? any thoughts on what it might be? I do have the 2 other engines. How hard would it be to trade out the tapered crank for a slotted one from one of the other 2 engines? Seems like the hard part would be swapping the main bearings.

I might take the engine off and start taking it apart but in the meantime little help........

 

[Carlman]

It is the ball bearing pull start mechanism mate take off the pull start and drop some oil into the hole in the middle of the square bit that bolts to the flywheel.

It might be so badly starved of lube that the bearings are sizing and kiling the engine.

 

[EagleTalons]

It is the ball bearing pull start mechanism mate take off the pull start and drop some oil into the hole in the middle of the square bit that bolts to the flywheel.

It might be so badly starved of lube that the bearings are sizing and kiling the engine.

That's what happened to my engine, I used ALOT of WD40. Never heard its screechiness again.

 

[wloch248]

That sounds like a very promising idea. Now that I think about it that sounds about right given the symptoms.

I will try that tomorrow and let you know the results. I could always use one of the other pull start covers from the other 2 engines if this one is too badly damaged.

I was really pissed that I had done all this work and then thought I fried my engine. Heres hoping! and thanks for the quick response!

 

[newrider3]

The recoil starter isn't the problem, it is the starter clutch attached to the shaft. Clean and lube it and you'll be good.

 

[Kaptain Krunch]

Also, if the governor is removed, dont rev it to redline without a loud, you can rev it a little,maybe 1/2 throttle or so.

 

[THE HUNTER]

if you notice the pull rope go limp when the screeching noise happens, its the starter clutch for sure.

 

[brendonv]

Its defiantly the starter clutch. Take the recoil off and u will see this little square shaft. It has a little bit of felt in it at the end underneath, drop some oil in the little pin hole in the centre and it will soak into the felt, that will lube the shaft and it will run good.

 

[THE HUNTER]

you can disassemble the clutch and oil the shaft (engine shaft under the square part of the clutch that goes into the recoil pulley)

but when you take it apart, make sure the engine is on its side (in the case of a horizontal shaft engine) otherwise you have a good chance of loosing the steel balls in the clutch.

 

[Carlman]

do not ude wd40, use a viscous oil like crankcase oil.

 

[wloch248]

SO I pulled the recoil off, pulled the screen on the flywheel off, pulled the starter clutch shaft off and pulled the ball bearings out. The shaft looks a little "rusted" no pitting or anything. The ball bearings look fine. I am going to clean the shaft and the inside of the piece I pulled off. What would be the best thing to lube when I put it all back on.

I have white lithium with teflon spray, regular bearing packing grease, and other misc lubricants around the garage. I was going to use some fine steel wool to clean off the inner shaft but what about the inside of the part I took off? Q-tips?

Thanks for all the responses, I hope this will take care of it. This is my first go cart (have had over 17 motorcycles and 5 cars) and some of this small engine stuff I just haven't learned about yet.

 

[jr dragster T]

Dont use any lubricant that will set up like a grease. Just use 30 weight motor oil.

 

[EagleTalons]

Dont use any lubricant that will set up like a grease. Just use 30 weight motor oil.

Hehe, from words of experience DO NOT use grease. I did and the little balls got stuck and all sorts of bad things... Now its cleaned. Just need my in/lb torque wrench and I'll slap her back together. Then I'll be...cruising or waiting for more parts.

Also, speaking from experience Hunter?

 

[wloch248]

Cleaned, lubed, put back together.

It idles fine and took it for its first full spin.

Thanks for all the input!

 

[brendonv]

good to see its all working. Its scary when the screeching happens huh. The first time it happened to me i crapped myself.

 

[THE HUNTER]

i kinda was. i havent actually lost any, except on an old 2hp horizontal shaft Briggs (it says "New Easy-Spin Starter" on it. lol). the clutch was broken anyway though, so i didnt even bother looking for them when they fell out. the older clutches had fewer pawls (idk what they are actually called lol) on the square part that engages the rope pulley. so they would wear out faster. other than that, the design has pretty much stayed the same over the years.

luckily the first time i took one of those clutches apart was on my lawn mower, so they all stayed in lol.



and yeah, when it first happens it kinda surprises you lol.