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I'm having a hard time getting started after the engine is hot.
I've read all the threads that suggest modern gas offers less "float" and so the carb float level needs to be adjusted accordingly.
Since I don't have a glass float bowl to help judge, can anyone offer any measurement guidance on float height adjustment for modern gas?
That might be the cause of your problem. But you may want to check other things too. Make sure your cable ends are clean and shiny. Make sure the grounds are clean and the nuts are tight on the starter solenoid and the ground points.
That might be the cause of your problem. But you may want to check other things too. Make sure your cable ends are clean and shiny. Make sure the grounds are clean and the nuts are tight on the starter solenoid and the ground points.
Thanks Abe.
I just redid all the electric connections, they are shiny, tight, and protected by dielectric grease.
I'm also getting some drips out of the carb, but only when it's hot. I've seen threads about the need to reset the float for modern gas, and for those with a glass bowl, it's easy to see when you have an overfilled bowl. For me, I just feel like I'm guessing....
Hard starting when hot could be caused by a few problems. If the fuel level is to high it may be spilling gas into the intake, flooding the engine or it is getting too hot. Do you have a gasket stack spacer between the carb and manifold? Also be sure your heat riser is operating correctly and not stuck directing heat to the intake. A general rule will place the top of the float level with the body when the carb is held upside down.
Hard starting when hot is usually caused by a rich condition. Next time it happens try holding the pedal to the floor to allow more air in (Do NOT pump the pedal, you'll make it worse. Just press down once and hold it there.) If it starts more quickly than it has been, under those conditions, you've found the issue. Also, you stated that fuel is dripping outside when hot, that also indicates the hard hot start by way of too rich, i.e. if it's dripping outside it's probably dripping inside as well.
One thing I've found, back when there were more 1904s around, is the hollow screw just inside of the inlet fitting, which attaches the needle and seat and float hinge to the body of the carb is a common suspect. The gasket that seals it is normally pretty tough to tighten properly without a good, wide driver that will span the slots. Not much chance of easily finding those kinds of screwdrivers in these days of fuel injection so you may have to make one from a flat piece of metal and use a crescent wrench across it to tighten the fitting. Get it tight but don't get too crazy, you don't want to strip the body. Sorry I can't give you more info on how much to tighten it, if there ever was a printed spec it's probably going to be difficult to find. One more thought... as I recall the float hinge assy. will try to rotate as you tighten the screw. Try to find something you can place under it that will buck it up as you torque the screw. What happens is the gasket will allow fuel to continue entering the bowl even though the needle is closed. Not a big deal when driving around as the engine will probably use more fuel than the gasket is leaking. The problem begins when idling or just after the engine is shut off and there is residual fuel pressure, which can actually increase as the fuel heat soaks without airflow under the hood. That fuel overfills the bowl and drips inside and outside the carb. Of course this is all academic provided all other portions of the carb are working and sealed correctly. I just recall it being an issue with 1904s as I recall pattern issues with other types of carbs. Crossing my fingers for ya!
Hard starting when hot could be caused by a few problems. If the fuel level is to high it may be spilling gas into the intake, flooding the engine or it is getting too hot. Do you have a gasket stack spacer between the carb and manifold? Also be sure your heat riser is operating correctly and not stuck directing heat to the intake. A general rule will place the top of the float level with the body when the carb is held upside down.
Thanks Jim.
I do NOT have a gasket stack spacer installed. I was hoping to find a phenolic spacer, but I guess the go-to for the 1904 is just a stack of standard gaskets?
Thanks also for the info on the heat riser. To be honest, I wasn't sure what the heck that was.... I checked, and it does seem to move freely.
If I don't get any results from the gasket stack, I'll pull the carb again and check the float height.
Hard starting when hot is usually caused by a rich condition. Next time it happens try holding the pedal to the floor to allow more air in (Do NOT pump the pedal, you'll make it worse. Just press down once and hold it there.) If it starts more quickly than it has been, under those conditions, you've found the issue. Also, you stated that fuel is dripping outside when hot, that also indicates the hard hot start by way of too rich, i.e. if it's dripping outside it's probably dripping inside as well.
Yup. I thought the same. I can't seem to reproduce any dripping out of the carb with cold, only once it's hot.
I'll try holding the pedal on the floor during the next hard start to confirm.
Originally Posted by CBeav
One thing I've found, back when there were more 1904s around, is the hollow screw just inside of the inlet fitting, which attaches the needle and seat and float hinge to the body of the carb is a common suspect. The gasket that seals it is normally pretty tough to tighten properly without a good, wide driver that will span the slots. Not much chance of easily finding those kinds of screwdrivers in these days of fuel injection so you may have to make one from a flat piece of metal and use a crescent wrench across it to tighten the fitting. Get it tight but don't get too crazy, you don't want to strip the body. Sorry I can't give you more info on how much to tighten it, if there ever was a printed spec it's probably going to be difficult to find. One more thought... as I recall the float hinge assy. will try to rotate as you tighten the screw. Try to find something you can place under it that will buck it up as you torque the screw. What happens is the gasket will allow fuel to continue entering the bowl even though the needle is closed. Not a big deal when driving around as the engine will probably use more fuel than the gasket is leaking. The problem begins when idling or just after the engine is shut off and there is residual fuel pressure, which can actually increase as the fuel heat soaks without airflow under the hood. That fuel overfills the bowl and drips inside and outside the carb. Of course this is all academic provided all other portions of the carb are working and sealed correctly. I just recall it being an issue with 1904s as I recall pattern issues with other types of carbs. Crossing my fingers for ya!
Wow. I never would have known to check there. Great info. Thanks again!
One more thing to check on any old vehicle is the lead from the coil to the distributor (not the coil wire.) The lead passes through the distributor body, under the breaker plate and up to the points. Many times that lead will appear o.k. at the points but underneath the breaker plate the insulation will have cracked and/or fallen off causing an intermittent short to ground condition and a no start condition. Normally I wouldn't suggest looking there as it wouldn't necessarily be a hot start only issue but, as it happens, that's exactly how it occurred on my 215 shortly after I bought it. Maybe the wire flexed when it got hot? Fifteen minutes and a piece of wire later it was fixed.
Thanks Jim.
I do NOT have a gasket stack spacer installed. I was hoping to find a phenolic spacer, but I guess the go-to for the 1904 is just a stack of standard gaskets?
Thanks also for the info on the heat riser. To be honest, I wasn't sure what the heck that was.... I checked, and it does seem to move freely.
If I don't get any results from the gasket stack, I'll pull the carb again and check the float height.
A stack of gaskets will work, The factory one was a stack stapled together, at least on all the 223's I have had. I've never seen any other spacers made from other material for a 1V carb. I made one from aluminum back in the 70's when I built the engine, probably not the smartest idea but I have never had a hot start problem and I run a 180 thermostat. After initial start up in the morning the rest of the day just requires a turn of the key and I don't even touch the gas pedal.
That heat riser in the exhaust manifold directs heat to the bottom side of the intake below the carb. Good luck, hope you find the problem.
A stack of gaskets will work, The factory one was a stack stapled together, at least on all the 223's I have had. I've never seen any other spacers made from other material for a 1V carb. I made one from aluminum back in the 70's when I built the engine, probably not the smartest idea but I have never had a hot start problem and I run a 180 thermostat. After initial start up in the morning the rest of the day just requires a turn of the key and I don't even touch the gas pedal.
That heat riser in the exhaust manifold directs heat to the bottom side of the intake below the carb. Good luck, hope you find the problem.
Thanks again HiBall, and Beav.
Turns out, the gasket stacks seems to have been it.
I added four more gaskets to the one I had in place already.
Went out for a 5 mile drive and I don't seem to have any leaks, or any trouble getting the engine started once hot.
Man, it sure is great to get an easy fix once in a while.
One more thing to check on any old vehicle is the lead from the coil to the distributor (not the coil wire.) The lead passes through the distributor body, under the breaker plate and up to the points. Many times that lead will appear o.k. at the points but underneath the breaker plate the insulation will have cracked and/or fallen off causing an intermittent short to ground condition and a no start condition. Normally I wouldn't suggest looking there as it wouldn't necessarily be a hot start only issue but, as it happens, that's exactly how it occurred on my 215 shortly after I bought it. Maybe the wire flexed when it got hot? Fifteen minutes and a piece of wire later it was fixed.
Beav -
Can you give me any tips on removing the breaker plate to get to the wire? I was out there today, but couldn't see how to get back there after removing the rotor.
Do I need to pull out the whole distributor?
Look closely at the washers on the connections inside the dizzz, some are nylon and some are brass. Make sure you didn't switch them so instead of an isolated connection, you have a short.
I took the wires out again last night. For the parts intended to connect, I cleaned them and added dielectric grease. For the parts intended to be isolated, I made 100% certain they weren't shorting out anywhere.
but I have never had a hot start problem and I run a 180 thermostat. After initial start up in the morning the rest of the day just requires a turn of the key and I don't even touch the gas pedal. 
