Sounds great. I almost have all the supplies to work through some of this again. Just waiting on USPS. Would you suggest unassigned oil, running a bit, then repeating the process a few times? Maybe using an engine flush or something like sea foam?Flip the carb over. Pressure test the needle and seat at 7psi for an hour. WET the needle while testing with some spray oil.
Carb float level should be parallel to the carb body, bowl mounting surface.
Flush the fuel system. Might have trash getting into the carb causing this.
Once the carb is not throwing up, dump the oil several times.
Good to know. All in effort to get a good running carb.Guys in his original post he said it is an opposed twin not a V Twin and the fuel pump is an intergerated part of the carb. So what you are saying about sliding the carb back to stop it from leaking fuel into the engine will not work. 42a707-2238-e1 is an opposed twin and does not have a bowl type carb. The bottom half of the carb housing holds the fuel. These carbs are very easy to clean just take the top off and clean the orficeses and blow out with compressed air. But be careful with the low speed welch plug you can blow it out and won't be able to find it.
SAE 30w is all you need.Sounds great. I almost have all the supplies to work through some of this again. Just waiting on USPS. Would you suggest unassigned oil, running a bit, then repeating the process a few times? Maybe using an engine flush or something like sea foam?
good question, I say appear because the the oil is about 1/8” up the dipstick when I check it about an hour after use. It’s not a lot and it’s hard to smell gas, but I don’t know any other reason why it would be increasing. I’m thinking this would be more from a leak down rom the carb after sitting. I didn’t want to try running it more to test this as I’m going to do some work on it. Right now I have some OEM gaskets on the way sometime today and then I’ll work on it when I can…not a lot of spare time on my hands lately so it may take a bit. While I have things apart I’ll probably check valves and clean carbon from the heads too. I’ll for sure keep you all updated though with what happens next.Your compression is ok.
Since that is the old opposed twin it very rare for fuel to get into the oil with the pump on the front of the carb type and you say you replaced the carb.
You say it APPEARS that fuel is getting in the oil.
Describe APPEARS?
I got a complete gasket set off eBay that was just delivered. Going to replace different gaskets like the intake and spacer gaskets to the carb. Just figured that while I’m at it I might as well do this. There was gas inside the intake under the carb so I’m guessing something is still faulty with the carb. I’ll continue to dig and see what I come up with.Just little bit of info and you may already know this:
You say your replaced the carb and still seeing the same thing.
If the engine oil is really clean and even hot and thin you can sometimes get fooled by the oil level by eyeballing. Sounds strange but true. Try this method for getting a precise level as gauged on the dipstick. Take a white clean paper towel and when you remove the dip stick wipe oil off, re-install dipstick and then lay the dipstick on the paper towel with the white towel flat and the dipstick flat level. The oil will leave a exact oil mark impression on the towel. Do not drag the dipstick, just press against the paper towel.
If the gas is going into the intake manifold when you turn the engine off you can see such on that model if you will park the tractor level, take the air filter off and then take a flashlight and look into the carb throat about every 15 min's and you can see if any raw gas is in the manifold at the bottom of the carb If the needle and seat is leaking the engine will usually be hard to re-start after few min's because it's flooded. Also usually if the needle/seat is leaking on the old twin L-heads the engine won't idle good and you can see lots of gas coming out the carb ventura when the engine is idling.
To check the needle/seat on the old Briggs 3 screw and 4 screw carbs, remove the carb from the engine, use a mityvac and with the carb upside down apply 5 psi pressure and it should hold this pressure for long time. If not holding pressure do not immediately assume it's the needle/seat, use soap/water spray bottle and check the fuel pump edges and the pulse port. If no bubbles seen then go to the needle/seat area. A very slow leaking needle seat (1psi in 5 min's) usually will not flood a running engine or flood the crankcase if the gas tank fuel outlet is below the carb.
At same time you are removing the air filter pull the pulse hose off the bottom of the fuel pump on the bottom of the carb. Be careful here because if any gas drips out it will hit onto the hot exhaust area. If any gas at all comes out the fuel pump diaphragm is bad. If it's a 4 screw fuel pump I re-build them with the carb in place. If it's a 3 screw pump the carb needs to go to the work bench due to small springs, etc, inside.
You might consider draining the oil about 1/8 inch low on the dip stick with the engine level and then later when you check the level park the tractor in the same place. The oil level on those engines can vary by quite a bit by not being in same level position and also it's common thing to see a really high level after the engine has cooled.
Installing a white or red Briggs in-line fuel filter is a good thing on those engines.
Just curious?
What gaskets are you replacing?
Do the needle/seat test that slomo and I suggested.
Seeing raw fuel in the manifold is not a good thing. Probably needle/seat leaking.
Also install a 60-70micron fuel filter. You say you installed a NEW carb and it's still same O. The Briggs red filters are about 150 microns are ok for gravity feed and can be used on fuel pumps feeds but the white finer filters are about 60 microns for fuel pump small engines. Using a 60-70 micron can cause a engine to starve for fuel when under a heavy throttle load. Probably trash particles getting to the carb, could even be old fuel lines.
Sometimes just cutting a old fuel line to install a filter will send trash downstream between the filter and the carb.
Thanks for all the tips and advice. I did replace all the fuel lines a few years ago, but I the filter is past due. I always use non-ethanol with some seafoam added to try to help keep everything clean. Try to keep the fuel system as clean as I can. I’ll look into trying to pressure test and see what I can come up with. Going to probably clean valves and cumbuation chamber over the next couple days and then I’ll be able to hopefully put back together this weekend or early next week. I would put it back together just to do the needle valve testing but I don’t have much spare time right now and have needed to do a thorough run through for over a year now.With the intake manifold showing raw gas the carb being tested has a leaking needle seat. You need to get that corrected before doing the other things.
If you don't have or want to purchase a Mityvac 8500 that does both vac and pressure you can find a blood pressure bulb on fleece bay for around $10 that will do the pressure test of the needle seat.
Sometimes you can inspect the needle tip under a magnifying glass and good light and clean the seat with a q tip.
Just a little hint. You might see two different brass seats in those carb kits, the one with the larger hole is for gravity flow and the small hole seat is for pressure feed.
I've ran those type carb's with the larger seat hole on those type carbs on their pulse pumps with no problem if they are good going in at first and using a white fuel filter and non-ethanol gas so as to keep everything clean.
Thank you. Set it and will check on it after a while.Mac
Tip the carb upside down
Apply pressure
it should hold 3 psi for hours and pop off he seat between 7 & 15 psi with nothing more than the weight of the float holding it closed
You can not test it on the engine unless you are pumping a liquid in there to make the float lift up and seal against the seat
Only 1 needle & float in a carb
Re-read what Bert said.How long should I leave it sitting to check for a leak? So far I’ve sat my carbs few hours each and saw no leak. I then sat one over night with a 1 psi drop over 10 hours.
it should hold 3 psi for hours
I was wondering more if it is normal to see a little drop over that long, or if it is indefinite amount of time it holds psi. When trying to research I see most people only test for about 10 minutes. I’ve worked a lot on my vehicles, but I’m new to working on small engines. Sorry for all the questions but just trying to figure out how to diagnose.Re-read what Bert said.
Here below
Thank you again. I’ll update in about a week when I’m able to get to everything. Good info on diagnosing. The tank is almost completely empty so I’ll probably just run the rest of the fuel into a tank I have for bad gas. Maybe the last batch I got from the gas station was old fuel or something. I’ll go get some new non-ethanol gas and follow your procedure.Yes, what you are seeing is normal.
Time to install and make a test run.
Sometimes a small prayer service helps on them Briggs just before doing the first test run after a operational procedure.
let us know how it acts.
When you start the engine let it idle and look into the carb throat. You should not see raw fuel being dumped. If you are seeing a mist of raw fuel when idling the carb is running too rich and the engine will not be smooth.
After its run and warmed up, if the carb has a adjustable idle jet do the smooth adjust with the engine idling slow then kill the engine and go back in about 5 min's and see if you see any raw gas in the intake below the carb.
On them old twin carbs that are really flooding severely gas will come out the top of the carb vent hole and can be seen with the air filter removed. The bowl vent hole is beside one of the air filter hold down screws.
When they are flooding this much the needle/seat usually is loaded with lots of trash or the fuel is bad and has a sticky substance that causes the float to stick. (the sticky stuff will actually get through the fuel filter at first but will eventually clog the filter also. The gas tank will smell like molasses when almost empty of gas. The molasses gunk is settled in the bottom of the fuel tank and the tank has to be removed for a good cleaning/flushing.
Yep, going to be looking into a few things. One thing I noticed is the linkage seems pretty loose with the governor. When at low idle it won’t rest against the idle screw. Going to try to figure that out. Maybe the gov screw loosened up on me somehow or something like that. If not that I’ll go back to musical carbs and see if they all act the same way or not.The faster it goes the more fuel per minute it needs
The way to diagnose your problem is to tackle one possibility at a time, eliminate it then look at the next
You should see no drop. Any drop at all indicates a leak.How long should I leave it sitting to check for a leak? So far I’ve sat my carbs few hours each and saw no leak. I then sat one over night with a 1 psi drop over 10 hours.
Take some pictures of what you are seeing. Post them up here. Words can get mixed up and the message doesn't get across. Of course a video of everything wrong would be priceless.Should there be gas settled below the carb at all?
What do you mean by this statement??? (are you talking about the engine or the video or what???)
You say: Takes a while to start as well
AND take the breather off and look into the carb throat while its running and see if you see a stream of gas when it's running at idle. Leave all the breather metal OFF THE TOP OF THE CARB while testing, it's just in the way for seeing things visually. The reason I ask you to do this is if you see any stream of raw gas in the carb throat at idle the engine is trying to run rich and flooding. The engine is intermittently loosing one cylinder and we need to try and determine if it's due to fuel/ignition or what. I've heard them Briggs twin L-heads lope like that at low rpms due to carb flooding (needle not seating when idling) and/or a magneto not firing on both cylinders strong. Most generally the 3/4 cam sound loping engine due to flooding at low rpms and can be seen as raw gas being sucked into the manifold throat.
Also post up a video of the engine at idle????(and leave the top of the carb exposed)
AND the test suggested in post #33 only take couple minutes.
I hear symptoms of a engine that is maybe flooding and only running on one cylinder for while and when both cylinders run it picks up speed is why the surging up and down
In your VERY FIRST POST you said:
I SHOULD ADD THAT IT'S RUNNING ON BOTH CYLINDERS.
What made you so sure of this???
Do you know how to make a static governor adjustment???
If not re-search such on-line and come back to us with any questions about such.
You can also find some videos of how to probably even showing your engine.
Sounds good. I’ll be out of town but when I’m back I’ll do those things you mentioned. It is actually a different muffler on it, but the youtube video in the video about the governor is an instructional one I found. It’s hard to come by the stock muffler that fits the MTD frame at a reasonable price so I was able to use a muffler from a zero turn instead. Saved myself $100 or so and my neighbor is welding the pipes for me. Also, I actually do have that repair manual. Been referring to it a lot as I’ve been trouble shooting. Might be getting some more needle valves as I’ve polished seats but still have leaks. I’m sure it will be solved here at some point…Your one picture is really dark and We cannot see what you are indicating that you see gas pooling in both cylinders????????????
Something to keep in mind on those engines is when they are not warmed up or hot and when you turn the key off the spark stops the governor goes wide open and the carb is dumping max gas into the intake manifold while the engine is coasting to as stop. If the engine is hot you will see gas vapor coming out of the carb throat. If the engine is cold you will see raw gas in the intake manifold below the carb because it's not hot enough to vaporize rapidly.
Some later model engines use a Anti Backfire Solenoid (ABS) on the bottom of the carb and it reduces the gas going into the manifold when the key is turned off.
Also you WILL FIND on some of the opposed twins that some engines ALWAYS require an immediate full choke for a quick start even when the engine is hot. Nothing is wrong, just the nature of the beast.
Do you have the Briggs service manual for that engine????
If you are going to keep that ENGINE you might want to eventually invest in a
Briggs Twin cylinder l-head service manual 02-271172 at about $30
Not to take anything away from this site, but here is a link to a site that has a really good small engine reference library for all kinds of small engine service manuals, but you have to be a member and post for awhile BEFORE YOU ARE ALLOWED TO VIEW AND DOWNLOAD SUCH.
Professional Power Equipment Technicians & Education Network (PPETEN) • Index page
With some searching few years ago I downloaded a freebie Service manual, BUT I also found a used manual on fleece bay at a reduced rate and just purchase such for the shop use.
Just a hint about static governor adjust. Ignore left/right/CW/CCW rotation of the shaft in the videos.
The governor shaft and lever is most generally turned/rotated in the same direction
that forces the throttle wide open when doing the static governor adjust.
Also on that engine the big screw that moves back and forth as you increase and decrease the throttle is the max RPM adjustment screw.
Sometimes this screw has to be adjusted to get the governor engine speed corrected at max throttle. (especially if the governor does not increase the engine speed enough when the engine is under a load mowing.
That bolt's nut that holds the governor arm clamp secured to the governor shaft coming out of the engine on those engines has to be tight. If you limp wrist the nut the lever will slip on the shaft and the governor will not work correctly AGAIN because the arm did not stay secured/locked to the shaft.
But be careful and not twist off the bolt or break the clamp. Use a 1/4 inch drive ratchet and a 6 point socket.
Leave the breather off the top of the carb push it outside and let it run at medium speed until it gets warmed up and do hot engine tests, killing and re-starting the engine checking for running rich, etc.
You are gaining ground for now, but sometimes Murphy will spring up again.
Them are good old engines when not worn out and only require little bit of TLC for long term use. You will find they are user friendly to work on when you get familiar with them.
That is a unusual exhaust on that one. They usually dump out and the muffler bolts in that square slot in front of the engine in the frame opening.
Just unbolt the muffler and it drops down out of the frame and leaves the two exhaust pipes bolted to the engine.
Also do not see a mower deck.
You will find that,
Patience is your friend.
Had same problem last year. Fuel is leaking into oil. The first sign something is not right is rope cannot be pulled to start engine. Had to have it repaired. They removed motor and did there thing. Now it runs fine. Cannot tell cost because they did other things while it was there.It appears I’m getting fuel in my oil. I thought maybe it was a carb so I replaced and I still have the oil level increasing after a mow. I just checked compression and one cylinder is 95psi and the other is 100psi. Any thoughts as to what the cause might be? it is a twin opposed Briggs 42a707-2238-e1.
I should add that both cylinders are running. New spark plugs this season and the both look great when removed.
I also checked my Tecumseh 195ea and it had 90psi. Is that low enough to work on the valves?
Another step we all could follow. I keep mine in the garage but still can get filthy inside.Cleaned out the fuel can
Crazy thing is the can was pretty slimy inside like Forest mentioned could happen. It’s never seen ethanol, so I’m guessing I got old gas last time around. I know one place I won’t be getting gas from anymore.Another step we all could follow. I keep mine in the garage but still can get filthy inside.
Glad to hear she is a runner.
Good to know. I’m going to verify later but I have full throttle set at 3,300rpm right now. Set the screw to about the same length as the previous and fortunately it matched right up. Good to know about those top screws, I’ll be putting some loctite on those for sure.Sounds good.
see you made lots of changes. Correct exhaust with heat shield between the carb and muffler. You say you changed the throttle/governor plate.
I've seen different colored gov springs on those and sometimes when changing them or finding one gone when working on old engines I just throwed on a governor spring, not knowing what color it should be and had to make a slight bend adjust to the metal governor arm behind the throttle plate to get a smooth governor control.
Keep a heads up on them 3 screws that holds the air filter metal pan to the top of the carb. I put green locktite on mine to keep them from coming loose and going into the carb throat. I also put the carb on full choke when removing/installing them to keep one from falling into the carb throat.
I’ll be putting some loctite on those for sure.Good to know. I’m going to verify later but I have full throttle set at 3,300rpm right now. Set the screw to about the same length as the previous and fortunately it matched right up. Good to know about those top screws, I’ll be putting some loctite on those for sure.
I actually did this right after I read your previous post haha. I have some blue loctite gel and used that. Should be cured by the next time I use it.I’ll be putting some loctite on those for sure.
Red locktite is a big NO NO. red IS THE PERMANENT ONE.
Use green or blue and strange that it's so expensive now days.
You just need enough to keep the screw from backing out own it's own due to the running engine vib's loosening the screw.
If a screw can be backed out with finger pressure once it's loosed it will back out on it own and fall into the carb throat then into the piston/head area eventually.
I've seen it happen MAINLY DUE TO SOMEONE LIMP WRISTING WHEN TIGHTENING AND THEY WILL STRIP EASY ALSO GOING INTO THE MAGNESUM CARB, SO lOCKTITE WORKS GOOD FOR SECURING THEM SCREWS.
No need in using small lock washers just get them screws little bit secure.