Running all fuel out of Carbs when thru for the day

[herndo]

Hello everyone. I'm brand new to this forum and I'm in need of some help. Is it OK to run the fuel out of your carbs at the end of the day to prevent slug build up in the carbs? Especially if your boat might set up for several weeks. Also I have a 25 gallon fuel tank. Usually my fishing trips are short distances so not alot of fuel is used. Trying to keep my tank full as not to let condensation form in the tank, over time my fuel goes bad. Is it ok to just keep around 10 gallons in the tank and maybe keep some Water absob additive in the fuel. Thanks herndo

 

[Scaaty]

Re: Running all fuel out of Carbs when thru for the day

Don't do it! If its a 2 stroke motor, you are not only cutting the gas off, BUT ALSO THE OIL! Put Stabil (a fuel stabilizer) in the gas,and add some "HEET" if you feel the need.

 

[bigbrownbuku]

Re: Running all fuel out of Carbs when thru for the day

if your bowl drains are easy to reach do it that way. stabiliser can be added to extend fuel life to 6 months. if your tank lives where the temperature is stable you shouldnt have condensation problems.

 

[JB]

Re: Running all fuel out of Carbs when thru for the day

Moving to Outboard Non-Repair Discussions.

 

[JB]

Re: Running all fuel out of Carbs when thru for the day

Running single carb, non-oil injected engines dry used to be very common practice but even that was risky as far as getting cylinders and cranks dry goes.<br /><br />Multicarb engines always empty one carb first and run those cylinders dry until the others go dry. Much more risky.<br /><br />Oil injected engines continue to inject oil even when the fuel line is disconnected. If they inject into the crankcase there shouldn't be a problem, but if they inject into the carb(s)or oil pump (VRO) serious over-oiling and carb bowls full of oil almost guarantee trouble.<br /><br />Makers now recommend leaving stabilized fuel in carbs after fogging for winter storage. That is the best solution for all non-EFI engines as well as EFI engines.<br /><br />Good luck.

 

[briannh1234]

Re: Running all fuel out of Carbs when thru for the day

Some people like to use a fuel-water seperator rather than heet. I don't know which would work better.<br /><br />I used to run my in-line 6's out of fuel all the time, but none of those motors lasted more than a few seasons. That was before I found this wonderfull site and found out running out of gas is bad.<br /><br />They ought to change the name of the carburator on a 2 stroke and name it carba-lubra-cator.<br /><br />- Brian

 

[dajohnson53]

Re: Running all fuel out of Carbs when thru for the day

Originally posted by briannh1234:<br /> Some people like to use a fuel-water seperator rather than heet. I don't know which would work better.<br />

Just a strong personal opinion, but I really can't figure out why anyone with built in tanks (and most with portable tanks as well) would not have a fuel separating filter. Cheap, easy to drain and/or replace, fool proof for prevention of water problems (if maintained, which is easy). I guess I understand that heet can do the job, but I just don't trust it as well as the filter, plus it's just another thing to remember to add, keep on hand on the boat, throw away the container, etc. etc. A much larger hassle than the filter, and not as sure. As I said, just an opinion!<br /><br />

<br />They ought to change the name of the carburator on a 2 stroke and name it carba-lubra-cator.

Now this is the smartest thing I've seen in a long time - should be in every thing where a 2 stroke carb. is referred to. Right on!

 

[Ronald1]

Re: Running all fuel out of Carbs when thru for the day

Add Heet to your fuel? I thought we were trying to avoid fuel that contained alcohol, especially for premix applications.... What did I miss?

 

[crazy charlie]

Re: Running all fuel out of Carbs when thru for the day

Ditto on the fuel water seperator!!!!!!Dont leave home without it.Charlie

 

[red10]

Re: Running all fuel out of Carbs when thru for the day

captain thats what i thought, wouldn't it run to hot and burn a piston.

 

[TOHATSU GURU]

Re: Running all fuel out of Carbs when thru for the day

We have always preached that running the gas out of the engine at the end of the day was the wisest course of action. It is certainly possible that doing that everyday for several years might lead to additional wear on the cyl. walls, but the average boater is more likely to have a filthy, gummed up carb from not doing it, than suffering any kind of damage. If you know you are going to use the boat the next day or next week...sure don't run the gas out. But, from personal expierence I can say that things come up preventing that planned use. Weeks turn into months. The slight risk of extra wear over the life of the engine is not worth the certainity of a carb job after a couple of months. Since the majority of engines that we see come in for problems that are related to dirty carbs I might be a little prejudiced. But, that's the way I look at it. If the next engine that I run the gas out of blows up I will have to re-think my position.

 

[Scaaty]

Re: Running all fuel out of Carbs when thru for the day

"not worth the certainity of a carb job after a couple of months." <br /><br />Oh come on...the gas aint that damn bad nowadays. And you also forget that while you ran that two stroke dry to keep it from gumming up in a couple months, all that cranking now to start it again is done with no gas/oil to those cylinders walls yet (which have probably rusted with no oil film anyway), dry bearings, etc. But do what you think is right.

 

[TOHATSU GURU]

Re: Running all fuel out of Carbs when thru for the day

It does not have anything to do with the gas quality. It has to do with evaporation of the lighter elements of the fuel. Down south that's a major problem. I'm not sure what " all that cranking now to start" has to do with the cylinder walls, bearings or crank journals. Residual oil stays in the block and does not evaporate. Keep in mind that gasoline is in and of itself a lubricant as well. Unless the engine has/had other problems there is practicaly no chance of any damage occuring.

 

[McGR]

Re: Running all fuel out of Carbs when thru for the day

I've always wondered about this practice. It always seemed to me that the bowls would never be completly dry by the time the motor quit. On some motors, OMCs in particular, the high speed jets are on the bottom of the bowls. I think these jets would become gummed up with the residual unburned fuel in the bowls. Therefore, I've always left the bowls full. When winterizing, I run stabilizer then pull the drains on the bowls. It's always worked for me.

 

[TOHATSU GURU]

Re: Running all fuel out of Carbs when thru for the day

In a limited season area I don't think you really need to run the gas out as winterizing would interupt the gumming up process. But, out west and down south, where people do not even know what winterizing is, I think it is sound advice.

 

[45_red]

Re: Running all fuel out of Carbs when thru for the day

The logic of running an engine out of fuel still escapes me, I run year round(2 stroke main, 4 stroke kicker). It almost makes sense for the four stroke as it has a single carb, but draining the carbs occasionally to dump any crud or water seems much wiser to me. By the way, I sure wish Elvin had been around a few years ago when I first got my Nissan. I had to learn a lot the hard(and expensive) way.

 

[TOHATSU GURU]

Re: Running all fuel out of Carbs when thru for the day

Think of it this way...and this does not usually apply to our Yankee brothers, Bubba has a brand new....whatever...lets say it is a Mercury oil injected, carbed 90 hp. He takes it out for the first time in the first week of January. He does not run the fuel out at the end of the day because he knows he is going to use the next weekend. NOT A PROBLEM. Next week he's out again running over those pesky manatee speed bumps. He again does not run the gas out because he knows he is going to use it again in a couple of weeks. Three weeks go by and he has to cancel his trip because of weather. IT'S STILL NOT A PROBLEM. He's not worried because he will go out next week. But, now the wife says " we have to go to cousin Jed's this weekend". Then the week after that he winds up with a couple of season tickets to the Ice Capades( I didn't say he was real manly). The next week it's a weather issue again. Then Fish & Game comes to see him about those speed bumps he ran over. Petty soon it's been four months since he last used the boat. Here's where it start's to become "A PROBLEM". Somewhere between three months and six months the fuel begins to evaporate out of the bowls. It's a slow process, but once it begins you are sliding at an ever increasing pace towards "varnish, sludge, gunk, whatever you want to call the residue left in the carb bowl." I have seen new engines with as little as six months on them that are sludged up. I have also seen engines, that after three years, the bowls are still clean. The only difference between the engines are Bubba's and Not Bubba's. Eventually you have to clean out the carbs. You can beat my pessimistic viewpoint by running a variey of cleaning agents through the gas, draining the carb bowls by hand and luck. Keep in mind that for people that winterize their outboards this is not an issue. But.....You need to do something. Draining the carbs is certainly safe, but it comes down to HOW LIKLEY ARE YOU TO DO IT EACH TIME YOU COME BACK? No matter what your intentions are...you are not going to do it every time, because you just know you are going back out next weekend. It's so much easier to disconnect the fuel fittings and let the engine run itself out fuel at the dock or when you get home running it out while you are flushing it. I have never heard of anyone who has damaged an engine from doing this...ever. And we are talking tens of thousands of service customers over the last 40 years.

 

[Ruan G Ellis]

Re: Running all fuel out of Carbs when thru for the day

Just Wondering about running the fuel out the engines if it is a premix then it shouldnt matter should it because the oil is mixed in with the fuel so no more oil is with the fuel in the carb bowl so it'll go straight to the engine with fuel???? I may have completely the wrong end of the stick but I think thats how it works.

 

[JasonJ]

Re: Running all fuel out of Carbs when thru for the day

My boss has a boat with a 175 horse V6 Merc that he tries to sell every spring. He pulls it out, struggles to get it running, no one buys it, and it sits until the next spring. It may get used once or twice in the year, never gets winterized. I was tasked this summer with the joy of seeing if I could get it running better so he could, once again, sell it. Seeing as it had the same festering nasty gas that had been in it for three years, I felt that the carbs had to be nasty. All he would do is add more gas, but it can't have ever been enough to make up for all that old gas (30 gallon tank). So this year he got all the old gas out, and I brought it home. I expected to see carb bowls chock full o' sludge and varnish. I pulled them apart and they were perfect. No sludge, no varnish, nothing. Turned out the main reason it was running badly was it had three different ranges and ages of spark plugs. Replaced those, motor runs better and it is still for sale at his house. <br /><br />I personally feel that multi carbed engines should not be ran out of fuel, but single carb engines it makes no difference as it won't be hurting anything. All I do with my inline 6 is drain the bowls at the end of the season and add stabil to the fuel as well as change the lower unit oil. Then the boat sits in my garage, patiently waiting for next spring to do it all over again.

 

[jleus]

Re: Running all fuel out of Carbs when thru for the day

If your concerned about evaperation, which is when the sludge like residues are created, but boat most of the year and don't winterize, as I do, on that week end you don't get to go at least go out and pump the carb bowls full with the primer bulb....or pull it out and run it on the hose for a few minutes. If the thing is so buried in the garage that either of those two options can't be accomplished then you would be doing something else to address the issue.