Gasoline Engine Question

[unrealman]

Okay i guess this would be the place to post this i dunno i don't really hear abotu this here hehe. anyweays i have an older 6.5 horsepower mower that i'm trying to fix. i was mowing with it erlier today when i got home it had a lil trouble getting going cuz it had sat there all winter but it started. now here is the odd part, my neightbor said hi so i turned the engine off and started talking to him for about 5 mins and then i went to start it again and it wouldn't start on the first pull like it usually did after i got it going. but finally i got it statred and i began to mow again and the engine began making poping sounds and i was like what the heck? so i lok at at the engine and all the sudden i saw this like flame blow out the tail pipe and it died. i was like....okay. and i went to start it again and it wouldn't start i tried for about ten mins. i looked at it and i thought hey maby it flooded. so i tightened the adjust ment knob and poured about a tea spoon of gas in the carburator i pulled it and it started right up then died(had it toooo tight) then i loosend it about half a turn and put another teaspoon in there, it started cycled and it was running kinda bad so i go to loosen the adj, knob and before i even get to it it flaires a white gas out the carburator and backfires again and dies, so i leave it there and i put another teaspoon in and i pull the starter, stand back, and in less than a second after it starts it flaires out afain and backfires and dies. any ideas?
Thanx for reading it http://sysopt.earthweb.com/forum/smile.gif

[Biff]

I would say its bad gas, gummed up carb, fouled spark plug, gummed up cylinder + piston rings causing low compression, or any combo of the above.

I would try the following procedures
Take out the plug and clean it, with the plug out sqirt some oil in the cyl, let it sit for a few minutes, then crank it over to get the excess oil out. Reinstall the plug drain the fuel out and replace, then try it.

Old gas in the carb dries and leaves a gummy film that can block the jets, I would try the simple stuff first, post back if u got problems.
Biff

[Rat]

Right up my alley (check my profile). You have a gummed up carburator. It will likely need to come apart and be cleaned. If your'e not comfortable doing this, don't.... a gas leak from from a loose hose or improperly adjusted float can cause a fire.

Rat...

[unrealman]

i know it'z not bad gas because there is a valve to empty the carburator before you put it into a storage for a long time, i drained it totally. also i was bored the middle of this winter and rebuilt the carburator and put it back in and it worked better than uaual. now another thing is that my float was looking kinda shabby when i put it back in and i didn't drain the carb after i did that(about 4 weeks ago). gas don't go bad that fast does it? i'm thinking maby the float sank. could that be it?
**EDIT**
about the spark plug i just bought a new one for it a couple days ago and that'z whatz in it, has a fresh oil change too.

[This message has been edited by unrealman (edited 02-08-2001).]

[randy48]

Get a can of spray carb cleaner, remove the fuel tank and spray the inside, this well help loosen the "varnish" build-up from the old gas. Let it sit awhile and dump it. If you're not comfortable removing the carb, spray the ventura (opening) excessively, wait awhile do it again. Pull the spark plug and clean or replace it. Pull it a few times to clear the carb cleaner (with the spark plug out). Replace the plug, re attach the fuel tank, make sure the fuel line is securely connected, add some fresh gas and cut away. Next time you store the lawn mower, either drain the gas or get some stuff called Stabil, this will stabilize the gas throughout the Winter.

[struggles]

This is a fairly easy problem to solve as this is a simple 4 stroke lawnmower engine, not a fuel-injected computer controlled duel overhead cam 8 cylinder.

An internal combustion engine regardless of what size or what it is needs three things to run.
1. Fuel
2. Spark
3. Timing
It sounds like your having a fuel delivery problem. One thing I like to do when this happens with a small engine is to get it started by force feeding it some gas, and then immediately covering the air intake opening with a rag till it pukes out. Sometimes dirt will clog some small airways or fuelways in the carb and the vaccuum from the motor will suck this out when you cut off its air supply.If no luck keep troubleshooting fuel delivery.
I'm envious. We just got 8 inches of snow! http://sysopt.earthweb.com/forum/frown.gif

[Linda91]

I cannot believe this post is here!!! I thought that I was at a computer related site! BTW, I need to clean my toilet, any suggestions on a cleanser?

LM

[Rat]

Gas normally does not go bad in a few weeks, BUT, winter grade gas will. If your float was looking "shabby", then get a new one from the local shop and replace it. Popping and backfiring is caused by a lean (not enough gas, too much air) mixture. If the float "sank" you would have a rich condition and normally it would not pop or backfire, you'd get alot of black smoke, then a stall. Pull the card apart, get some spray carb cleaner and soak it good. Use a can of air duster to blow it clean (unless you have an air compressor). use a small siff wire to clear out the jets if necessary. Put it together with a new float and bowl gasket, the float should be adjusted paralell to the gasket surface. If there is a filter on the fuel line, use the carb cleaner to clean it out and use the air duster (or air compressor) to blow it out backwards. Clean the tank if necessary, look inside, if it is shiny inside, it doesn't need cleaning. make sure there is no water in it. Put fresh gas in and your'e good to go.

Rat...

[CMonster]

Linda91 bleach is usually best.

On the mower - If not electronic ignition it sounds like a bad capacitor or wet points -anyway I think everyone has just about covered the subject but perhaps overlooked that there was also a very small/tiny possibility of sticking valves.

Anyway the three basics of 4-stroke engine are:

1. a mechanically sound engine

2. spark at the right time

3. right fuel/air ratio

[Dave_H]

CMonster would be correct as usual. http://sysopt.earthweb.com/forum/wink.gif
Cleaning a vitreous china toilet bowl (http://www.friendlyplumber.com/plumbing101/how_tos/clean_toilet.html)
Dave

[RayH]

Toilets? Phosporic Acid does wonders!

[big_block_buick]

if it ran great last year,and the only things new are rebuilt carb and spark plug.i might investigate those..is it the correct plug.and i'm not sure on small 2 stroke engines.do you have to gap the plug.maybe the gap is wrong or the plug is wrong..

[MrEd]

Sounds like it's running too lean to me. It's getting too much air, and not enough fuel. Try adjusting the mixture control a little. It's a little screw with a spring on it. Of course if you're anything like me working on things, there's always screws left over and you don't know where they go. That's probably the one that you put aside, thinking it might be important later. http://sysopt.earthweb.com/forum/biggrin.gif

-MrEd
http://sysopt.earthweb.com/forum/smile.gif

[codybear]

got to be bleach...it'll kill all those germs as well as clean the bowl http://sysopt.earthweb.com/forum/smile.gif

[HfdWolfPack]

Private Pyle used a toothbrush and some ol' fashion elbow grease. got that badboy to show a reflection.
I, myself use well, ...now I know why I enjoy being married...j/k

[sys-eng]

Before tearing into the carb again, check the fuel line and filters. There is often a small filter on each end of the fuel line. Particularly at the carb end -- this is a very small fine filter that clogs easily.

At the end of the season, be sure to use StaBil fuel stabilizer instead of draining the carb. Draining the carb will cause the fuel pump diaphram to dry out and quit working causing a lean fuel problem.

Although very simple engines, they can be VERY agravating!

[PassnThru]

I gotta go with the float on this one.
Of course, the usual also applies:
1)Did you disable the governer to increase the speed? If so, clock it back to default and see if it still has the same problem.
2)It might be a heat related issue - try some bigger fans on the cooling fins on the head.
3)Try reinstalling the carb - sometimes that fixes it.

http://sysopt.earthweb.com/forum/wink.gif

[unrealman]

oaky i'm gonna try to clean the jets with that cleaner your talking about, there is no fuel diaphram on this thing or at least none that i can see. the float didn't sink i took the carb apart lastnight and left the thing floating in waster all night and most of today and it never sank. about the screws with the springs on them. ther are three. one is on the trottle thingie so i nkow that is the idle speed. there is one at the bottom of the fuel bowl and one at the top of the carb. another thing is before it started to backfire it would die when i put the throttle up all the way. (too much gas?) one more thing is that i took the muffler off of it and the inside is got a black coating(maby been running too rich?????) i would like to know what those stupid screws are for the top one seems to make it run better just sitting there and the bottom one makes it run better when it'z under a lod( any ideas?)
Thanx

[Barney]

One screw is to adjust the air (probably the one on the top). The other 2 are probably to adjust the the throttle and and sprinkler (is that what you guys call the little thing with the hole in it?). The one on the bottom would be to adjust the sprinkler.

Ronald

[bdunn]

Put drain some of the gasoline and refill it with CAM2. The engine will run really hot but it will get all the crud out. Next fillup regular fuel should work fine.

[Mykex]

Well I have to interject with the dumbest thing,my small engiene repair teacher just loved to preach this. Check the keyway! LOL Dont do it realy,I just had to get that stupidity out. Its been buried for a long time and has to come out once and a while.

[struggles]

Definetly dont use fuel stabilizer. This stuff is junk! I've had to work on numerous snowblowers this winter all of which had stabilizer put in em. It jells up and deposits **** in the fuel bowl every time. More of a pain in the ***** then anything. Gas takes longer than 3 or 4 months to go bad.

[CMonster]

I'd really like to hear back from unrealman once he gets the problem solved.

I too would agree that if the equipment always functioned well until after work was done to it then it is wise to carefully recheck the work done first. I have seen floats put in backwards, needle-seat loose, w/o gaskets, check-balls out of place or missing, jets reversed, and just about anything else you can think of.

Looking at this statement: "Also, I was bored the middle of this winter and rebuilt the carburator and put it back in and it worked better than usual." I would not necessarily condemn the carburator, but I question how long it was tested after the repair.

This is just my $.02 as a 19-year veteran auto, truck, and equipment mechanic (by no means an expert), certified in: emissions test and repair, various ASE, refridgeration,antilock brakes, hydraulics, ARC, gas, MIG welding, yada..yada.too many other meaningless certs to mention -anyway I fly by the seat of my pants. 8 -years with Los Angeles DWP, 2-years building Police special and patrol vehicles with the LAPD, and 9-years of hell working for the general public.




[This message has been edited by CMonster (edited 02-12-2001).]

[unrealman]

Okay i fixed the problem. i took the carburator Totally apart again and i fugured out the prob. The float sank. my neighbor said that he had smelt the emmisions from the ting(didn't notice them) and he said that yeah it was running WAY the hell toooooo rich. it was a ten year old float so i guess ya can't blame it for sinking. also helped a lil to spray it down with carb cleaner before reassembling it and while it was running. it mows great now( adjusting took about a freaking hour) but i finally got it. Thanx for the ideas. another thing that i noticed after i started messing with it is that the thing don't die anymore when i try to rev it up all the way. it just goes faster and faster and faster. http://sysopt.earthweb.com/forum/smile.gif http://sysopt.earthweb.com/forum/smile.gif http://sysopt.earthweb.com/forum/smile.gif http://sysopt.earthweb.com/forum/smile.gif hehe anyone have an idea on what i can do with a 16 year old briggs and stratton 3.5 hp engine? i'm thinking over clock it and stick it in a very areo dynamic case for racing. what ya think http://sysopt.earthweb.com/forum/wink.gif

[krusty the klown]

Ah, Briggs and $hatton. They seem to either run flawlessly or are a right dog and you can never get the thing to run right.

Good job on the mower, but how's that vitreous enamel getting along?? I'll expect it to be clean and fresh! Mmmmm...!

[This message has been edited by krusty the klown (edited 02-14-2001).]