ok, granted, the motor has been sitting for a while. but ive redone pretty much everything. now im down to the last part and i wired everything up, for kick only. i have checked the battery, and its fine. but i got to kick it over, and its turning over but its just isnt quiiieeeet getting there to fire up. its very close. also, new oil and new gas... so i was just curious if anybody else had this problem? or if this sounds like a pretty familiar scenario to anybody? and as to what may be the problem... new starter solenoid also...thanks.
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carbs .
You should open them up and clean them. Have a search on the forum for some tips. If your bike has been sitting, there is probably some gunk built up in your carbs which is blocking some passages. Also check your fuel delivery (petcock, inline fuel filter, gunk in the tank) and check your carburetor intake boots for holes or cracks (the rubber things)
Do a compression test on the motor.
...and if it has even half-way decent compression...back to the carbs. I truly mean no offense, 'cause I've been there, but I always chuckle to myself whenever I hear someone say: "can't be the carbs, I just cleaned them."
...mine originally took 5 strip downs to get them clean enough. Now, 4 years later, I'm in the middle of doing it again. I had to refer to my own posts and my own pics to reassemble one of them.
...mine originally took 5 strip downs to get them clean enough. Now, 4 years later, I'm in the middle of doing it again. I had to refer to my own posts and my own pics to reassemble one of them.
Boilerhouse
XS400 Member
Matt, check this:
take the carb bowls off and make sure that the orifice that is in the bottom of the bowl is not plugged. This orifice leads to the chamber on the side of the bowl for the starting jet circuit that the post on the main carb body draws from. If this is plugged no fuel will get to the starting jet (choke) and subsequently the engine to start. Comprende?
take the carb bowls off and make sure that the orifice that is in the bottom of the bowl is not plugged. This orifice leads to the chamber on the side of the bowl for the starting jet circuit that the post on the main carb body draws from. If this is plugged no fuel will get to the starting jet (choke) and subsequently the engine to start. Comprende?
Compression is damn near spot on 150 in each cylinder. I can smell gas getting to the motor and I know for a fact the carbs have had a thorough cleaning. So I traced the wiring back to the ignition unit and there's a little hot spot on it. I'm putting all my money on that being the issue. But I'd still like to hear some input as to if anyone has experienced this with the ignition unit?
So your getting gas, but is the switch on the handle bars turn to the on position? what year bike was this? does it have a kick stand safety or some other device? Some of us create a signature line so that no one needs to ask what year bike we own.
See now, I know last year I was able to do a extremely stupid trick, but I knew my bike would start. How big of a hill do you have infront of you house??? like i said stupid trick, I only suggest it, cause if it doesn't work, you will have to climb that hill. A long gentle slope is all you need for my trick to work. but its risky. You could drop your bike, or run into something on the side of a road, (like a car, a lamp post, garbage can) since none of us think you have your carbs clean enough, put a whole can of seafoam into the fuel tank. Put the tank on PRI (Primary source for fuel) If that does work, it will smoke for some time, and then the engine will want to die, constantly till you can get the crap blown out of the carbs. There are a few more spots, like if your bike is a earlier than 81, you might need a points and a condenser. The sparkplug might be the issue, or the wires. When was the last time the oil was changed? or the valves check?
Well welcome to the group, and keep helping us with adding items to the thread, "Tell on yourself" I am in there once or twice
Tobie
See now, I know last year I was able to do a extremely stupid trick, but I knew my bike would start. How big of a hill do you have infront of you house??? like i said stupid trick, I only suggest it, cause if it doesn't work, you will have to climb that hill. A long gentle slope is all you need for my trick to work. but its risky. You could drop your bike, or run into something on the side of a road, (like a car, a lamp post, garbage can) since none of us think you have your carbs clean enough, put a whole can of seafoam into the fuel tank. Put the tank on PRI (Primary source for fuel) If that does work, it will smoke for some time, and then the engine will want to die, constantly till you can get the crap blown out of the carbs. There are a few more spots, like if your bike is a earlier than 81, you might need a points and a condenser. The sparkplug might be the issue, or the wires. When was the last time the oil was changed? or the valves check?
Well welcome to the group, and keep helping us with adding items to the thread, "Tell on yourself" I am in there once or twice
Tobie
Carbs are clean, spark plugs new, wires, new, switch is on, no kick stand safety, I've ripped everything off the bike except the bare essentials for the motor and the head and brake light... Oil just changed, new gas, and no hill, I live in the desert haha... And compression fine. The only things I could possibly think of would be the igniter unit because it wanted to fire up right at first then I looked and a fuse was blown so I tired it again and again then another fuse went, then from all this I traced a hot spot to the igniter unit. That's the only issue I've found with anything is that little hot spot... So I'm just curious now as to if anybody has had this issue with their ignition unit and if so did it do the same thing? And it's a 1980
Sounds like something is grounded wrong and or is shorting out.
Curious about the pic of the burnt spot in the wire you found can you take a pic?
vineyardmh
XS400 New Member
Pull spark plugs ....connect spark plug wires to spark plugs and ensure the spark plugs are touching the engine. Turn the engine over and see if you are getting good spark on both plugs. No spark - no run!
I am also finding the same problems. I replaced the coils, wires, and plugs, new reg/rec combo with the two plugs coming off of it. Recently took apart the loom to ensure that there were no breaks or shorts in the wire. New battery 2into1 exhaust new carb boots adjusted the needle valve on the carbs to run richer. Adjusted air screw out 4 full turns( in Denver, not much o2 in the air). Reset the gap and the timing to be dead on. New gas new oil. I have spark. 78 xs 400 motor on 80 xs 400 frame. It just will not turn over.
Sorry Matt don't mean to hijack this thread butt sounds like we are the same boat
Thanks in Advance for any help
Sorry Matt don't mean to hijack this thread butt sounds like we are the same boat
Thanks in Advance for any help
So I went back to the drawing board and couldn't figure it out wiring wise, then it dawned on me to switch the could wires around... I just out the plugs from one to the other and vice versa... Because it was sounding a lot like a misfire and would occasionally backfire really loud... But as soon as I switch the cool wires it fired right on up no issues. Been riding it since.
It is always the simple things
Have you sprayed some starter fluid down the throats to see if it will fire up?
BTW, it'a not an "air screw", it's an idle mixture screw. More turns out=richer, not leaner on a BS34.
