l20b running on 3, r1 carbs

[frank88]

Hi all,

 

So the story is, the truck was apparently running fine when i bought it two years ago but has sat in my garage since then. I put some r1 carbs on it and it started and idled perfectly 4 or 5 times.

 

I left it for a week and when i started it, it's running on 3 cylinders. It will only run with the choke on and dies if you try to give it some gas. I have pulled the leads on the distributer and all are sparking strong, number 4 lead makes no difference so that cylinder isn't firing.

 

Could I please have a list of things to check/eliminate to help me solve the issue?

 

I pulled plug 4 and also 3 and they both looked like this, very oily, which isn't good is it!?

https://imgur.com/Ll4u5iO

 

[Bastard_510]

39 minutes ago, frank88 said:

Hi all,

 

two years ago but has sat in my garage since then.

 

I left it for a week and when i started it, it's running on 3 cylinders. It will only run with the choke on and dies if you try to give it some gas. 

hello

have you put gas in it in the 2 years? if not gas can go bad and cause things to get clogged or sticky. if your carbs are running only when the choke is closed that is a red flag that the main jets/main fuel supply to the engine is clogged and need cleaning. rebuild your carbs if that is the case.

Edited September 15, 2019 by Bastard_510

[datzenmike]

So you have never driven it and do not know the running condition of the engine, yes? Did you install a new fuel filter with the carburetors?

 

Running only with the choke on and dies when given the gas would indicate a lean condition to me. Is the intake and gasket tightly sealed on the head? Carburetors snug on the intake? Dirt could have gotten in and blocked idle or running jet(s). Carburetors would have to come off to see. While off check the float drop setting.

 

Then....

 

Put a plug in the #4 lead and set on a grounded surface. Crank engine and confirm spark is getting that far.

 

Take the valve cover off and check that all valves have some clearance when the cam lobe is facing up. As long as the rocker wiggles that's good enough for now. A compression check will confirm that there IS enough compression for normal running.

 

 

[frank88]

Thanks for the tips, I'll be checking all of this.

 

Yes new gas, new fuel lines and new fuel filter (with the new pump).

Carbs have been cleaned and check prior to fitting but I'll will check jets for blockages.

 

Is it worth blocking the vac nipples on the inlet too?

[Stoffregen Motorsports]

If it "ran when parked" and then the first thing you did prior to bringing it back to life was installing the R1 carbs, that's the first place I would look. Intake manifold gasket leak, too much fuel, not enough fuel, etc.

 

Did you do anything else before firing it off?

 

Try a new set of plugs.

[frank88]

Well initially after fitting the r1 carbs it started and ran like a dream. Then suddenly didn't! So yea I guess that is number 1 suspect.

 

I did have a rummage around under the dash looking at some shady wiring but there seems to be spark so cant think what i could have knocked and affected under there. I tested the fuel pump and that's running fine too so I'll have to take the carbs apart

[scooter]

definitley the carbs have gunk in them. ethanol in pump gas now ruins everything. it wouldnt hurt to do a compression test or pull the valve cover for an inspection like mike said

[datzenmike]

I've had zero problems with our gas. My gallon of mix for the weed eater is 5 years old and I just shut it off every fall and leave outside in the shed. Starts every spring on the 3rd pull. Bought a 620 box from the wreckers and it had 5 gallons of fuel in the tank. It was sitting in the yard for 5 years, 3 of them without a gas cap or flap, I know because I took them. And it RAINS here. I dumped the fuel out and through an inline filter and threw in my truck. Never a problem. 

 

I worry about it but nothing happens.

 

[scooter]

7 hours ago, datzenmike said:

I've had zero problems with our gas. My gallon of mix for the weed eater is 5 years old and I just shut it off every fall and leave outside in the shed. Starts every spring on the 3rd pull. Bought a 620 box from the wreckers and it had 5 gallons of fuel in the tank. It was sitting in the yard for 5 years, 3 of them without a gas cap or flap, I know because I took them. And it RAINS here. I dumped the fuel out and through an inline filter and threw in my truck. Never a problem. 

 

I worry about it but nothing happens.

 

not up here, leave gas in your lawnmower for three months and the fuel lines literally turn to bubblegum

[datzenmike]

Weird eh? Weed eaters have the smallest jets in them. It was the same with my chain saw, fired up after all winter outside under a bench. I think one of the makes will sell non ethanol.

[Bastard_510]

2 hours ago, scooter said:

not up here, leave gas in your lawnmower for three months and the fuel lines literally turn to bubblegum

one time  my dad put some 5+ old gas out of a boat into his truck. i got a call the next day asking why his truck wasnt starting. turns out the gas was so incredibly bad that it stuck almost every valve open. that was only 3 gallons out of the 20 the truck took so a little bit of old gas in the tank can mess everything up.

Edited September 16, 2019 by Bastard_510

[wayno]

I have gotten free pressure washers, blowers, almost free edger and small tiller and none would run, all of them had that crap pump gas in them, I turn them upside down and drain the tanks, pull the little drain plug in the carb bowl and empty it, then I pour a small amount of fresh gas in the tank and let it drain out the bowl, then I put the drain plug back in and I fill the tank up with fresh non-ethanol gas, and usually by the 5th pull it is running.

I also hear about customers saying their new rototiller will not start(bought last year), I ask them if they use pump gas in it and did it sit all winter with that crap gas in it, all of them say yes it has pump gas in it, I tell them to dump it out and buy non-ethanol gas at this place, there are two places that sell it, one east side and one west side, on the pumps it says for classic cars and small garden use engines.

I use pump gas on my pressure washers as I trade off every couple months to keep the gas fresh, also I drive that most every day till recently, when I drive the truck around it mixes up the gas in the pressure washer tanks, it's when the equipment/vehicles sit unmoved for long periods of time that the gas separates/goes bad.

[frank88]

Interesting because I dumped the old and put about 10l of new in and that's it in terms of cleaning it! Looked clean inside when I used a torch though

[datzenmike]

Ethanol will mix with gas but it also mixes with water. Pure ethanol will absorb water from the air. Not hard to imagine this mix becoming quite watery over the winter. Unlike gas where water sinks to the bottom of a container. I can't see you guys not having your gas caps on tight like I do. Maybe something else is at work here. From end of Oct to April it's damp and cool/cold briefly to just below freezing.

 

I guess if storing, drain the gas or let it run till dry. Vehicles, start every month and let run long enough to thoroughly warm them up. My 710 will sit till next year, I topped the tank up for this.

 

 

[banzai510(hainz)]

ck to see if a lash pad fell out of that cylinder that is not working. Do as Mike said pull the wire and see if it changes  maybe lash pad fell out or the lash is too tight letting the compression go out the exhaust

 

I would never let gas sit 2 years in a car I run it  for a few every 3 or 4 weeks . and have StaBil additive in there. or cycle out the gas for new.

 

as for weeeater 2 stroke gas I let that shit go for 5 years and never have proplems. Maybe the oil preserves the gas.

[Stoffregen Motorsports]

On vehicles that sit for long periods of time, I will use race gas. I know, it's expensive, but it does not deteriorate like regular pump gas. I am mainly referring to the dirt bikes, quads and that kind of stuff. Fuel additive (Stabil) has the same effect.

 

This modern gas just flat destroys fuel system components and it is not unheard of for a new looking fuel line to have chunks taken out if the inner lining, which can find their way to the needle and seat or even into the carb and clog a jet. The CJ5 I built recently needed new fuel filters because the new fuel rusted them out from the inside. They were brand new less than a year ago! I replaced them with OEM Toyota plastic filters to eliminate that problem.

[datzenmike]

My 710 doesn't have a lot of miles on it but has survived 7-8 winters of sitting Sept to April and zero problems with the fuel system or start up and after in the spring. Has the original everything but the carburetors now. Same with weed eater and chain saw. So what's different. Rains on average 1,375mm or 13.75 meters or just over 45 feet. So not exactly dry. Most falls Oct-Jan. when the car has been sitting over a month already.

 

So is the gas down there sold full of water to begin with?

[Stoffregen Motorsports]

This taken from https://axleaddict.com/misc/Pros-and-Cons-of-Ethanol-in-Gas

 

One of the issues with ethanol is that it attracts water and it does break down faster than gasoline. This is not much of an issue with transportation vehicles. But with small engines this can be a huge problem.

With water absorbing into the fuel, there is the chance that rust will form on the interior of the engine. For obvious reasons, this is bad for any piece of equipment. The particles that get into the gas from rust flakes will clog up the fuel filter sooner or later. It is possible that these flakes will also cause damage to the pistons, rings, seals, and any number of other components of the engine.

Ethanol increases gasoline vapor pressure which may cause a vapor lock in the carburetor. This fuel starvation will prevent the engine from starting. This is an issue in higher altitudes and hot weather. Make sure to be storing gasoline with an ethanol mixture properly and to use it in a timely fashion.

Gasoline with ethanol decreases the life of the engine and its parts. The alcohol is not good for seals and causes a quicker break-down. Having a cleaning agent like this constantly in a small engine that was not engineered for this fuel mixture simply ages it at a faster rate.

The ethanol in E10 gas breaks down quickly. An MTD area representative informed me that E10 begins to break down within 3 weeks. This break down creates clumps in the gasoline mixture at some point and this may clog the filter, carburetor, fuel line, etc. To help prevent this a person should purchase a product such as Sta-bil and add it as directed to their gas. This will help prolong the life of the gas and keep it from harming your small engine as much. Talking with an area small engine repair shop, the E10 breaking down is the major cause of equipment being sent in. And after inspection, diagnosis, repair and testing it generally cost between $50.00 and $60.00 even when the issue is simply bad gas. They drain the system and add new gas that has a stabilizer in it after diagnosing the issue.

These issues are more dramatic with small engines, but they also occur with transportation vehicles. The difference being that transportation vehicles are now being designed for this gasoline, but there are still effects such as above that occur - just on a lesser scale.

[wayno]

There is a reason that all metal fuel tanks at gas stations in the US were removed and replaced with plastic tanks(as far as I know), that ethanol fuel eats metal, it's the same reason why they put plastic fuel tanks in vehicles now and why small engines have plastic fuel tanks/carburetors now.

I don't know what kind of fuel they sell in Canada, maybe real gas?

Our classic vehicles have metal tanks............

 

[datzenmike]

It's marked "Up to 10% ethanol" No one here complains of horror stories of using or storing gas over long periods of time. Lots of quads, sleds, chainsaws, outboards, bikes. You can buy 'Non Ethanol Gas' at the pump but not all stations have it.

 

Plastic storage containers don't rust from ground water or corrode from galvanic action. It's hugely expensive to replace them so even an extra few years longer lasting is a worthwhile savings. In cars they are safer in an accident, lighter, (everything is about lighter) cheaper (everything is about cheaper) to make and easier to mold in intricate shapes, don't rust on the outside (or insides) like metal ones, absorb damage that would dent a metal tank. If 10% ethanol does deteriorate fuel tanks it's minor and not the reason for the switch. My gas tank is 43 years old and has ethanol in it since they began blending it in the 80s? and it's been parked every winter since 2011? And over 40 feet of rain falls on it during the year. 

 

Years ago there was a big scandal where a meat supplier was injecting water into the meat to increase the weight. Maybe the fuel suppliers are blending water into the gas or the ethanol, like putting sawdust in sausages to extend it. 😄

[jagman]

Gee Mike, you must have very low humidity there in God's Country.  I repair mowers in VA.  We have high humidity nearly year round and I have experience with ethanol mix.  Here the gas can go bad within 3 months if stored without a fuel stabilizer such as Stabil  or Sea foam.  I have been recommending all my customers use one or the other to prevent water accumulation and corrosion in the carb bowl and water in the tank.  While it is not an empirical study the stuff works and my intelligent ( Deep end of the gene pool  - non trump like) customers now rely on their machines starting without trouble throughout the year.

[datzenmike]

Water can't accumulate or get in if the lid is on tight. Water doesn't just appear it either comes in with the gas or it leaks in through loose gas caps. My gas mix was 5 years old and sat out in the snow. What was in the weed eater sat all winter outside under cover.

 

Why don't the gas companies put fuel stabilizer in their product???

 

Humidity is around 90s in the winter for 3 months and can drop briefly below freezing, dropping slowly to and 66 in June and slowly up again. On average

[bottomwatcher]

Yes working on boats in Florida the ethanol has been extremely destructive and why marinas do not sell it. Marine tanks are unpressurized and open to the atmosphere with fuel vents only a foot or more from the surface of the water. In the most basic form ethonal fuel experiences "phase separation" you will see globs of fuel/water rolling in the bottom of a small tank. Ethanol is extremely detergent and will knock years of varnish and deposits loose requiring frequent filter changes. Also it attacks fuel hoses. The ethonal resistance hoses have a whole different issue. They are plastic lined and the liner separates when exposed to vacuum pressures when the pump sucks fuel from the tank to the motor. Cars fuel up regularly so it is not quite the issue. Plus the tanks are not vented to the atmosphere but have sealed caps and charcoal canisters. I use stabilizer in everything I am not running for more than a month. 

[wayno]

Remember these photos Mike, I drained this fuel out of Uncle laulau's 521 tank, it had only sat in one spot maybe 6 months, and it had a fuel cap.

 

 

Just because it has not happened to you Mike doesn't mean it doesn't happen.

[datzenmike]

I do remember those wayno. Not saying it's not real, just assume our gas is the same, and maybe it isn't.

 

I wonder what the stuff is on the bottom? water and ethanol? That would make the gas above it even lower octane as ethanol has an octane rating of 110 or 114? Crazy shit.