Motor help

[2or3wheels]

OK, i got a hs 50 by tecumseh. i got it on a cart long gone unfortunally. but i had the motor running (badly) but timing was off. so i pull side cover off get timing correct. still same issue. its firing out of the carb. im starting to loose patience. do i look at timing key on flywheel or what? the motor was just rebuilt and i dont want it to just sit. thanks

walter

 

[philip metzner]

walter, the piont lobe could be on up-side down, if it has one, or a valve could be sticking, or spring could be broke or not hooked up right, or valve lash not set. also the cam timing could still be wrong! take the valve spring cover off and check things out. if everything is o.k. then slowly turn the motor over wile watching the valve tips and springs. you will see when one valve is closeing and the other opening, and you will notice that for a moment both will be open a little. this spot is valve overlap, and the piston should be at dead top.--phil

 

[2or3wheels]

Ok thanks. im going to take the starter off and look at the key to see if thats ok, easiest thing to do, and if thats not it im going to do what you said thanks.

 

[2or3wheels]

Still problems

Ok i have the thing all apart, i took flywheel off and everythings good in there. when i turn the flywheel over by hand with the head off and there seems to be a gush of pressure comming out of the crankcase vent below the carb, is this normal.i also cant get the vale cover off to look at the tips, i believe this is where the pressure is comming from.

 

[philip metzner]

probably normal robin, when the piston goes down the crankcase gets smaller and it pushes the air out there.

 

[philip metzner]

if you have the head off grab hold of each valve when they are open and pull on it to make sure the spring hasnt come un-done. i know this a very good test but if the spring is not connected the valve will pull out. i had this happen once. i have also had a bad plug act like that. does the engine have points?

 

[philip metzner]

sorry about the robin thing i get mixed up sometimes.-phil

 

[2or3wheels]

ok, we did pull up on them. so where do i go now? it does have points.

 

[philip metzner]

ok, if the valve springs seen to still be attached, you can check the valve timing by, slowly turning the motor over by hand in a normal clockwise direction, watching the valves and piston. turn untill you see the exaust valve open and start to close. when the exaust valve is neerly closed you will see the intake begin to open. at one point both valves will be open just a hair at the same time. this should happen when the piston is at the top. if it is, then the cam is in time properly. this is hard cause i dont know what has happened to the engine, or if anything has been done wrong. let me know about this and then well move too something else.--phil

 

[2or3wheels]

i got the plate off, springs ok, yes th cam timing is right i looked at that. i got the motor on a kart. the guy though the rebuilt motor was locked up. we tookit apart and a bold had vibrted loose and rubbed the flywheel, and stoped it. that where i am now. it may be the points but i dont know how to time those. it does fire but out of carb last i tried week or so ago. i just dont know.

 

[philip metzner]

oh, i think you said that your engine is a tecumseh, right? if so there is two bolts that hold the magneto assy. to the block. i hope nobody has moved that. make sure no wires from the coil or condenser are shorting out, and make sure none of the wires including any little ground wires from the coil are broke. i would replace the points, condenser, plug, but you can make sure the points are clean by removing them and drawing real fine sandpaper tru the contacts untill there bright, then draw come plain heavy paper thru them to remove any grit. re-install the points and turn the motor untill you reach the widest point opening and set gap with a clean feeler guage. i dont have a book, but im guessing at .018 inch. the engine fires the plug when the point begin to open and lose contact. if you have a ohm meter available or a battery test light you can connect one lead to the point termanal and one to ground and rotate the engine. when the contact is just broken the piston should be just a little befor top. if it is then the ignition timeing is right and you have some other problem. again i have had bad sparkplugs do this.--phil

 

[RobertD]

i've got an engine data book out in the garage somewhere, but I couldn't find it quickly and it's too darn cold to tear the place apart -- but that sounds about right on the gap. i'll look again tomorrow.

 

[2or3wheels]

thanks so muhc ill do that. i cant believe all of this. when i saw the bolt i though whoo hooo ez fix. thats changed. so i tested the plug it has terrific spark so is it not the plug? also before i took it spart the compression was extremy high for a 5 horse. is this because of the rebuild or what?

 

[philip metzner]

i dont know about the high compression unless there was alot of oil or something in the cylender?? it is very possible to have a plug that fires good with no compression on it, but wont run!-phil

 

[2or3wheels]

Really? i never heard of that. i will get plug tomorrow and let you know. if this works im going to kikc my slef. after all of the didassemby and it was just the plug!!! anyways thanks.

 

[robin]

sorry about the robin thing i get mixed up sometimes.-phil

HAHA you got me confused then

 

[2or3wheels]

I did it. we purchaced a tune up kit, replaced the points and condenser. put it all togeather, sprayed a little carb cleaner into carb, ran on 1st pull. im going to do the tuneing late, my clutch only goes on 1/2 the way. whats that? looks like a clip to yake apart, what to i do?

 

[philip metzner]

great, now you know a bunch more about small engine then you used to. thats why this stuff is great for people. i dont know about the clutch, probably something simple. maybe need to polish the shaft up with sandpaper, or burr on the keyway.--phil

 

[2or3wheels]

i use fine sandpaper on both shaft and the inside of the clutch. whats burring? i tried without the key same thing, im confuse. also how do you tell if a clutch is worn out?

 

[philip metzner]

a burr is just a piece of raised up metal, like a nick from a chisel. without seeing the shaft and clutch i cant realy help here. will it go half wat on from either end of the clutch or just one way. i have seen clutches that have built in keys and they are in two sections and they get twisted out of alignment. does your clutch have a built in key or just a groove in the hub?-phil