MF-135 Gas Perkins - fuel flow

I'm having issues with my MF-135 gas (Perkins) that keep me thinking insufficient fuel flow but not certain, so I'm looking for opinions from folks who are familiar with this set up.

Fuel line is 1/4" steel - blown clean
New sediment bowl with strainer - clean, no debris visible
New fuel filter at carburetor
New Zenith 13338 carburetor

With fuel flow turned full "on" at sediment bowl under tank and plug out of carburetor bowl, the fuel flow is a bit more than a trickle but not a full stream.

Does this sound sufficient, and is there possibly a strainer in the tank, out of view, that could be clogged before fuel is getting to the sediment bowl? Thanks in advance.

Not sure about the 135 but on my JD 40 when you take any fuel line off that tractor and have a steady stream of gas. So yeah, there could be a strainer inside the tank thats clogged, Also on my JD40 theres a valve on the bottom of the tank before the sediment bowl, you probably would have noticed it but maybe your's has one as well and its partially closed.

Thanks Clayton for your response,

With a search I found an old thread of someone with a similar problem.

https://forums.yesterdaystractors.com/viewtopic.php?t=1355978&postdays=0&postorder=asc&highlight=fuel+flow&start=15

That thread said a pint jar should fill in 2 minutes or less and it turned out in his case to be an intermittant wiring failure to coil, so I have a few things to try tomorrow.

Well, I just had to go out to the shop and try to run a wire direct from the battery pos terminal to the coil (new) pos terminal to see if wiring, ignition switch, etc, is the culprit, but the situation is still the same, the tractor runs at first sorta like an old hit-and-miss engine and if I don't catch it quick enough it will backfire and die. So tomorrow I'll try the drain timing test to see how long it takes to fill a pint jar.

I purchased a couple of pint jars today and then did the fuel flow test. The result was approx 1/8 pint thru carb in 2 minutes. And nothing more than a continuous trickle. Soooo, guess I'll start up the line from carb to tank. I also got two extra 5-gal gas cans to have for draining the tank if needed.

My 202 had gas flow issues. The tank had lots of rust and crud which plugged up the in tank strainer and to some degree the tank valve, sediment bowl and the in-carb filter. I read that some had a tank cap vent that was plugged not allowing any air into the tank.

To verify my issues, I removed the line from the carb and with it higher than the tank and the cap off, blew into it to free the blockage. It did and it ran much better.

I cleaned out the tank by removing it and dumping the contents. I removed the tank strainer, valve and sediment bowl. I cleaned the carb filter and installed a clear serviceable filter so I could monitor the crud. My plan was to reinstall the tank strainer, valve and sediment bowl once I knew the crud was gone.

At first I was cleaning the newly installed clear filter assembly every 30 mins to an hour. Eventually it cleaned out enough so now about every 25 to 50 hours I clean it out. I do not know if i am going back to the original setup or leaving well enough alone.

It was suggested to clean the tank using a high pressure sprayer at the car wash. It was winter time and I wasn't comfortable with it drying out.

Good luck,
BR

Hi BR,
Many thanks for the info and troubleshooting steps, very timely in my case and much appreciated. When I got tractor (just last month or so) it had a cracked sed bowl so I purchased a new sed bowl assembly but installed only the new strainer, gasket & bowl since fuel tank was near full, so the old sed bowl base is still in tank. At that time I also cleaned the fuel line and put a new original-type filter at the carb. All was good for an hour or so of work and then the trouble started, so a clog in the tank sounds very possible. I wouldn't be surprised to find the tank clogged above or at the sed bowl. I have the gas cans now to dump the old gas to see what's above that old sed bowl, and I'm still not sure if there is a screen in that tank above or at the sed bowl that could be clogged, so I'm looking forward to finding that out. And a great idea to remove the non-visible filter and use a visible filter. I will report back on what I find.

Many thanks again,
Marty

does it do it when engine is cool? i had a 135 with the perkins gas and it would run great
till it got hot then shutoff like you turned key off. long story short sediment bowl was
getting too hot and vaporlocking. made a heat shield to go around it and never had any more
problems with it.

Many thanks Valley, there is a shield on my 135 behind the exhaust manifold that butts up to the sed bowl. Did your 135 have this shield and then you made another shield, or was this shield missing on yours? When I look at this shield I can't help but think how it must transfer the exhaust manifold heat directly to the sed bowl since the shield butts up to - and touches - the sed bowl bracket.

When I first got this tractor it did as you said, would run 20-30 minutes and then shut off, but I think I isolated that to a bad coil that would heat up then shut off and then start back up after cooling down for 15 minutes or so. BUT, I can't be certain it was the coil since now the gas line is clogged and I can't get it to run that long. Your info is sure good to know. I'm thinking of making a temporary gas line, larger than 1/4", to go straight from the tank to the carb (without the sed bowl) just to prove one way or another that the fuel flow and/or vapor lock is the issue. And I was thinking of doing away with the sed bowl permenantly and substituting a visible in-line filter that is further away from the exhaust manifold, probably on the other side (carburetor side) of the engine. Hopefully I'll get this test done within the next few days, maybe the weekend. Many thanks again and much appreciated, Marty

you said new fuel filter. Are you sure you have the right one. I put one on my 165 from the parts store looked identical but not. It had a fine filter on the inside made for pressure not gravity flow and it would not pass enough fuel.

Thanks Dexter, I got the filter from Yesterdays Tractors as the exact one for the 135 Perkins Gas, and it looked identical and the tractor ran ok for a while and then something stopped up to a trickle, so it could be the filter, don't know yet if tank or sed bowl screen (no debris visible) or filter at carb, but hopefully getting geared up to find out.

Here's what I did this afternoon. We are lucky to have one of the old-type parts houses, you know, one of those stores that has everything you can think of and also some things that you couldn't even think of.... I went in with a sed bowl base and the old carb and got a custom new fuel line made up to go from tank to carb with a cut off at tank and another cutoff for the bottom of the carb and a clear filter for the middle. I should be able to get the new line going immediately away from the exhaust manifold headed to the back of the engine to prevent any possibility of vapor lock (I hope), and then I will be able to see any crud from the tank in the filter. Hopefully I'll find out the condition of everything and where the blockage is during the weekend and I'll report back what I find, with hopefully good news.

Many thanks to Clayton, BR, Valley and Dexter for the responses and advice, much appreciated.

I had a similar problem on my 8N that wound up being poor flow through the fuel shutoff valve. Some deterioration of a rubber seal on the stem of the needle was not allowing full fuel flow through the shutoff.

Finally replaced the shutoff valve and got it running properly.

Good luck.

Thanks Powrguy, great info and something that I never would have thought of or suspected. I'll report back after I change out everything in the fuel line and check the tank.

I have a 1965 135 with a perkins gas engine and have gone through similar issues you are having. I was having suspected fuel starvation problem. I got rid of the glass fuel bowl filter completely as I believe the shut off was causing me problems. I threaded in a hose barb into tank and ran rubber 5/16 fuel line around back of engine to rt side. I then put a inline plastic shut off valve similar as you see on some lawn tractors and a fuel filter threaded into the carb.

mine did not have a heat shield. not sure if it ever had one but the sediment bulb would
burn you after puling hard. the gas would bubble in bowl so i assume that was my problem
because after i added homemade shield it never did it again. you would think they would
have put further away from manifold but they didnt.

Thanks Bowtie & Valley for the info. It sounds like we had similar issues. I did straighten out the low fuel flow by removing the sed bowl and running a new fuel line to the carb and wow, then lots of fuel flow, BUT, still engine not running right and back firing. The reason for not reporting back sooner is that I have done everything including new points, plugs, etc, and still engine running like crap. Finally, this evening, a certified tractor tech came over - a pro with a fresh mind - and he checked all ignition, compression and even timing, all good, and fuel flow good, turns out that my brand new $300+ Zenith carb is bad. It was good for about an hour or so of work and then went bad. It is loading too much fuel and the adjustments do nothing. All else has now been ruled out. Its been a bummer to take so long to find the problem but on the plus side it now has lots of new wiring and parts on the fuel and ignition side. I'll report back again when the replacement carb comes in. Thanks again to all for the very helpful info.

(quoted from post at 20:02:49 02/26/19) Thanks Bowtie & Valley for the info. It sounds like we had similar issues. I did straighten out the low fuel flow by removing the sed bowl and running a new fuel line to the carb and wow, then lots of fuel flow, BUT, still engine not running right and back firing. The reason for not reporting back sooner is that I have done everything including new points, plugs, etc, and still engine running like crap. Finally, this evening, a certified tractor tech came over - a pro with a fresh mind - and he checked all ignition, compression and even timing, all good, and fuel flow good, turns out that my brand new $300+ Zenith carb is bad. It was good for about an hour or so of work and then went bad. It is loading too much fuel and the adjustments do nothing. All else has now been ruled out. Its been a bummer to take so long to find the problem but on the plus side it now has lots of new wiring and parts on the fuel and ignition side. I'll report back again when the replacement carb comes in. Thanks again to all for the very helpful info.

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Theses perkins are great engines but they do seem very tempermental. The one thing that you may not have thought to check is for a blown intake manifold gasket that will cause a lean mixture and mimic a fuel starvation problem. The problem is you cannot buy this gasket sepperatly it only comes in a master gasket kit. I made a new one out of gasket paper.