That extinguisher is not working as a proper reservoir, exactly like Froth suspected.The hose is connected to the nipple and the nipple is connected to the hollow rod that's inside the extinguisher and submerged in coolant. But it might be sucking some air through a hole on top which I have blocked with a screw. But I have noticed some coolant leaking from that part. But it's really mild.
The OEM "reservoir" has high/low fill lines to be filled to after purging the air from the system.That extinguisher is not working as a proper reservoir, exactly like Froth suspected.
I don't know if you have determined if the fan is running/turning on but I described test for that in this other overheating thread.I will make a checklist of all the points mentioned and go over them one by one. It could be the wiring as I did some modifications to them. It could be the extinguisher, so I will run the hose directly to submerge it.
What should I be looking for concerning the backfire or afterfire (whichever it is).
The hose is actually the stock hose, I just wrapped thin wire around it and painted it red. But there could be a slight leak. So I will see if I can drill the top hole bigger to run the hose all the way down.Two more points related to over heating...
So after looking at your pics I get what look you are going for now, I guess it would be "Rat Bike".
I've seen enough rat rods to know stock elements are usually replaced with something uncommon, ie a shifter mounted outside the the drivers door (if it has a door!), brass plumbing hardware, beer can overflo, or in your case a fire extinguisher.
I'm not sure what that red square thing on the right side is, under the tank/against the motor, but it could be restricting air flow.
The hose size from the rad to the extinguiser looks to be way bigger than stock.
This could limit the ability of the vacuum to pull coolant from the tank.
I suggest you cut off the internal tank tube, drill out the passage way/elbow to accept a hose similar in size to the stock hose.
I understand the big hose wrapped in red you have now is a design element, so to keep it, thread the smaller/stock size hose thru the big hose/thru the drilled out elbow and down close to the tank bottom.
And angle cut the hose so it doesn't sucked onto the bottom of the tank.
Usually just removing the mufflers will cause miner drivabiliy problems. remove/messing with the air box will cause MAJOR drivability issues and a rabbit hole you don't want to go down if you can avoid.I was just reading something on causes of backfires, and it mentioned that running too rich or lean could cause backfires. (I am sure you gentlemen already know that) but I am just learning as I go. I used to ride bikes back in the days, but never owned one.
I noticed the fuel filter that's between the ****pit and the fuel pump it doesn't get fully filled. Could it be that the pump is sucking air that's causing the backfire?
I just want a bike to get back in practice. So far I have become a better mechanic than rider.By removing the airbox you have reduced the ventury affect and created increased air flow.
Taping over about half of the filter length might get better drivability and avoid going done that jet rabbit hole.
Something that's adjustable/cheap and you could use RED duct tape to go along with your RED color scheme
If your plan is just ride to bike nights ok but a bike that bogs or spudders is not good for riding in traffic, regardless of "power".
Restricting the air is way cheaper to do than increasing the gas, other options to reduce the air flow are putting a big washer with a smaller than carb center hole between the filter and carb, and my favorite stretching 1 or more wool socks over the airfilter...you could use RED socks
By "seems to run weak" and "it struggles between 900 and 1000 rpm" does it stumble/pop/ or just not rev??The bike seems to run too weak. The carbs are rebuilt and clean. It was running fine before, but now with 3 turns out on the pilot screw, and the idle screw almost a quarter in, it struggles between 900 and 1000 rpm. View attachment 288973
What have I messed up this time?
The battery is an old battery and it's drained out, I use a booster to start the bike. Could the weak battery causing it to run weak?
Oh boy!🤷🏽♂️By "seems to run weak" and "it struggles between 900 and 1000 rpm" does it stumble/pop/ or just not rev??
And was "it was running fine before", when before?, why are you still messing with it?
I don't really understand how putting the filter element back on/without the foam could be restricting the air flow.
Why not try some tape as I suggested earlier, it would take a few minutes and cost nothing.
I see where no one else is responding here anymore.
You have so far ignored most of my advise and gone off doing other things that did nothing.
Turning the mixture/idle screws in and out will not fix anything for you and now you are questioning the battery.
I'm gonna have to bow out it this point and let you continue on without anymore input from me.
good luck on your quest,