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Post by urbanmadness on Apr 20, 2015 15:03:34 GMT -5
That means we have ruled out the petcock. From there we put the petcock back in line and then do the same to the filter. With those two things ruled out, we can move on. then we will start checking for vacuum leaks.
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Post by urbanmadness on Apr 20, 2015 14:56:48 GMT -5
yeah. And then plug the vacuum line that goes to the petcock.
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Post by urbanmadness on Apr 20, 2015 14:47:01 GMT -5
yes, you just need to ground it. Revisiting the vacuum petcock.. If the diaphragm is ruptured, cleaning it won't help. by pass it for now to rule it out but only if your tank is above the engine. If it is in the floor, then you can't bypass it because it's actually a vacuum driven fuel pump. Plenty of spark with both plugs(I keep a spare) Gas tank is above the engine. So I should be able to get a gas/out petcock with a shutoff and no vacuum line from ace, yes? Meanwhile I killed my dang battery. just get a piece of fuel line, and run it from the tank nipple straight to the fuel filter. That will take the petcock out of the equation. Also make sure fuel is flowing thru the fuel filter in the correct direction. There should be an arrow on the filter that indicates the direction the fuel should flow. |
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Post by urbanmadness on Apr 20, 2015 14:31:57 GMT -5
yes, you just need to ground it.
Revisiting the vacuum petcock.. If the diaphragm is ruptured, cleaning it won't help. by pass it for now to rule it out but only if your tank is above the engine. If it is in the floor, then you can't bypass it because it's actually a vacuum driven fuel pump.
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Post by urbanmadness on Apr 20, 2015 14:23:54 GMT -5
just bring an extra spark plug with you. Better then removing and replacing a spark plug out of hot head. (better for the bike too)
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Post by urbanmadness on Apr 20, 2015 13:47:00 GMT -5
fuel filter? Installed backwards or plugged? Just something else that gets overlooked.
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Post by urbanmadness on Apr 20, 2015 13:27:27 GMT -5
It's not the airbox hose.
Check to see if you have spark when it "dies".... could be a bad coil.
The coil and CDI's sometimes go bad, and quit intermittently. usually when they heat up.
Other things to check, Vacuum petcock/fuelpump, and intake manifold. Make sure it's tight around the carb.
Just read that your valve last is set to .005. It will make less vacuum if they are too loose. Try .003 intake and exhaust. (just for diagnosis) If the pump or petcock has a diaphragm rupture, is would do all kinds of misbehaving, including killing the fuel supply (yes I know you smell fuel but it its coming thru a vac line, you will have fuel in the wrong place)
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Post by urbanmadness on Apr 20, 2015 8:54:18 GMT -5
After hooking a wire to the engine, if that doesn't do it, then try the same thing with the frame. A wire from the neg term on the battery to the frame.
Grounds on older bikes can give fits.
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Post by urbanmadness on Apr 20, 2015 8:50:56 GMT -5
I'm going a different way. This to me doesn't sound like a fuel problem.
When it dies and won't start back up, are you sure you are getting spark? I'm thinking bad CDI Module.
AND you would smell gas if it wasn't firing.
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Post by urbanmadness on Apr 19, 2015 22:35:18 GMT -5
The cam is not the problem. Weak tendioner, maybe. I dont know if the side plsy is excesive or not. A little play is normal. Check the side play on your old stock chain.
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Post by urbanmadness on Apr 19, 2015 15:52:40 GMT -5
ok... general maintance is pretty easy. Most complicated item is adjusting the valves. And the idle problem sounds like valve adjustment.
You asked about General Maintenance, so here it goes.
Valves should be adjusted every 1000 miles or so
Oil, should be changed every 500 or so.
Belt should be inspected at 1000 miles. I just replaced them at 2000 miles. Variator weights need to be inspected when you have the belt off. Lub the clutch needle bearings at the same time.
I'm sure others will chim in.
Tools needed, 1/4" drive socket set (easier not to over tighten bolts). Feeler gauges that go down to .003" (I use what they call go/no go feeler gauges), cheapo impact wrench (harbor freight has one that works well for under 50 bucks), a couple of impact sockets (I just bought a set) A decent set of screwdrivers, a flash light. A drain pan that will fit under the engine. You also might want to pick up a set of combo wrenches.
Things that make it alot nicer to do this kind of work are a "magnet on a stick" cause you will drop stuff, and a magnetic dish for putting screws, nuts and bolts in and a small tool box.
Note: wrenches and sockets should be metric.
I know this list sounds a bit more complicated, and it makes the job(s) sound more complicated but these bikes are really simple machines and a good way to learn.
As always, ask questions, read the "How to's" and you will do just fine.
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Post by urbanmadness on Apr 19, 2015 13:44:46 GMT -5
Do you have wire and crimpers? Make a jumper wire from the negative from the battery, and then run it to a bolt on the valve cover. See if the problem goes away.
It's acting like a bad ground wire.
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Dead scooter
by: urbanmadness - Apr 19, 2015 13:36:53 GMT -5
Post by urbanmadness on Apr 19, 2015 13:36:53 GMT -5
May I ask why you need to replace the carb, as opposed to rejetting it (which would most likely need to be done on a new carb anyway?)... also what size is the engine you currently have... is it a 150cc?
BBK kits on a 150 don't offer a huge displacement bump (unlike the 50's) and a well tuned 150 will out perform a poorly tuned 150 with a BBK kit.
A new piston, barrel and head are pretty cheap. The engine probably dropped a valve, but when you put it together, make sure you jet that carb, or it's gonna happen again. It's time consuming, but it will keep it alive.
Do it right the first time, and keep asking questions. Uni filter isn't always a good mod either. They run lean with a uni, unless you re-jett. Same with a header.
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Post by urbanmadness on Apr 19, 2015 13:24:02 GMT -5
The other thing to look at, is weights. Not all weights are the same width. Make sure they move freely in the ramps. You can mix and match weights, but they must be staggered.
Tuning the variator, of course makes a huge difference with these bikes. By and large the biggest bang for the buck on a 150 as the bbk kits don't make a huge difference unless you are stroking them.
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Post by urbanmadness on Apr 19, 2015 13:16:08 GMT -5
I always leave mine on unless I have to work on the fuel line or change the filter , or if you are working on the carb. Always shut it off when you turn off the bike. (I'm really bad about it on my bike, actually, but it is best practices) The purpose of the petcock, is for the carb. If the carb has a leaky needle valve, it keeps it from flooding the cylinder with fuel when the bike is sitting. this keeps it from hydro-locking on start up. I had one go bad on a bike that had sat, and I ended up with about 1/2 gallon of fuel in the crank case because the previous owner bypassed the petcock. |
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