Won't start, but have fuel and spark :s

S

Sammy D

New Member
Hi all.

I bought two engine kits and have them both installed on two bikes. Was out last night, with a friend. He turned his off with the kill switch and then couldn't start it again. It was pitch black and after some faffing we saw that one of the wires at the connector had come out, we plugged it back in and it still would not start. As it was too dark, we rode home normally to sort it out in the morning.

I've been fiddling with this thing all day and I can't get it to start. It even more annoying as I am a mechanic!!

The kill switch is fine, I've had it apart and no probs there. Engine will also not run with switch not connected.

Spark. I have a healthy spark visible in daylight. I have also swapped the CDI and plug from the other bike and it sparks just as well, as does the suspect CDI on the other bike. So that has totally ruled out the CDI and/or magneto and/or spark plug.

Fuel. The plug is stinking of fuel. No blocks anywhere. I've had the carb to bits and inspected for anything blocking jets that might be causing it to flood. All is clean. I've also left the plug out for a few hours to let some of the fuel vapour out after lots of failed attempts.

Air. I've had the filter off, it still won't run.

So to summarise, I have a good spark, a good amount of fuel, all the air it wants, but it won't run.

This brings me to the final point. Compression. Pushing the bike along with the clutch out, is hard and when trying to kick start it, it is just as hard as the kit on the other bike. The clutch does not appear to be slipping.

This engine was running very well yesterday. It was noticeable quicker than the other bike too. They are both running the same fuel/oil mixture.

I can't get my head around this! The other bike is fine, and even with all the bits from the other bike on the broken bike, it won't run! It could only be compression or clutch as far as I can see, and both of them seem totally normal.

Any clues guys?

Thanks in advance!:-||
 
Sammy,
What IS your fuel mix and what are you mixing? 32:1 is a good starting point. Sounds like its flooding a bit(allot) just to rehash, white wire terminated, blue to blue, black to black, kill switch to black and blue, carby not extremely tilted etc... as a mech, you know the three things you need for a motor to run. Suggest plug change and a long hill(check the plug wire too, I've seen them spark OUTSIDE the motor but not run installed. Hope that helped you.

Mac
 
Howdy Sammy, welcome.

I got no clue. (nor have an answer for you, snork) Seems just about every thing except Chinese gremlins has been addressed. Worst part is it will turn out to be some odd thing and cause you to slap your forehead. I think thats part of the design.

Please be sure to post what it turns out to be.
 
Thanks for your replies. Just reporting in. I've come to the decision that it's flooding massively. I've had the carb apart and bent down the fangs that operate the jet to try and shut off the fuel better. The carb is almost at about 45degrees forward tilt which is probably too much although it ran yesterday. Now for the killer, I've pulled the block away from the piston and turned the bike upside down and about a cupful of black fuel and oil poured out. I think that's my problem! I did that after watching a black liquid drip from the exhaust. I'm running around 20-1, I'm going to bring that up higher tomorrow. I can only presume that there was soo much fuel and oil in the crank case, that on compression, there was no vapour for the spark to ignite, just a black filthy muck.

So, jobs for tomorrow are to adjust the angle of the carb to a more level position, adjust fuel/oil mix and try again now the crankcase isn't like a puddle!
 
yea,
They can hydro loc(misnomer), fuel lock actually, pull the plug and give it a walk with the clutch out, should clear it. I've seen some "interesting" angles of the carbs, they work pretty well, even when steeply mounted.
 
any luck,... my first bike won't start either,...
same thing,... all looks good, spark, fuel,...

gonna try to walk out the fuel lock, thanks MAC,...!
 
the last post from Sammyd was 3 months ago. i wonder if he ever got it running?

or worse, the engine exploded from being full of fuel and he doesn't have any fingers left to type with...
 
ok,... I'm in the same boat as Sammy D was,..
AND, I can't figure out how to start a 'new thread' on this site,...?
so, till I get that straight I just reply on already started threads,...
but my motor won't start,..
it's a Lucky Early Bird 66cc
I got fuel in the line and to the carb,
got spark, checked it several times,
wired blue to blue, black to black,
got the kill switch disconnected,
all wires not in use capped, the white and the 2 from the kill switch capped at this time to avoid that being the problem,

keep hearing different gaps to have on the plug and different mixes to use,...
I have a 16:1 ration now (as suggested by the kit I bought) is that to rich for a first start ?
and .032 gap in the plug,...

I tried in my driveway several times, slighty down hill but was going pretty good when I released the clutch,... no go,
then took it to a big hill,... same thing, just not firing up,...


I'll try any suggestions,...

it is cold here, around 40 today, but the days i tried it I brought the bike out from in the house, so it was room temp,... now it's been out in the garage and is cold,...
__________________
"Don't let your meat loaf,...."
see my bar trick vids at
YouTube - heyscuba's Channel
 
2door said:
Choke open?
Tom
Click to expand...

uh,,, choke is arm 'up'
which means choke 'on'
which means choke 'closed'
right,...? that's the way it looks to me,...
I tried it up and then down and in the middle,
tried it with quick start, without,...?
what is most people's experience, motor's starting right up,..?
 
They're all different. Some love the choke, some don't need any. Only experimentation will tell you what your particular engine wants/needs to start easily. Typically it only takes fifteen to twenty seconds of running to get things stabilized then the choke needs to be open (off, lever down). Temperature will play into the time it takes. Colder days might require a longer half choke period. Warmer days will require less.
If you have fuel, ignition and air (choke off, open) then your engine should run.
Starting can be a problem until you find that just-right-spot and combination of air and fuel that your engine will like. Keep trying; you'll find it.
Tom
 
First Hello all!!!

I really need some help on this. I have spark ( stock spark plug ) fuel in carb, sparkplug wet with gas. Tried choke @ different positions, no kill switch, wiring on point. Checked carb for needle/ throttle movement, that seems good as well.

She sounds like she wants to start but no go.

Neebie here and this is my first built and this is driving me nuts. Will hate to give up and take to shop.

Any help will be highly appreciated

Thanks!!!
 
Well the first thing I would do is get rid of that stock plug, (there total crap!) Look for an NGK, B5HS, OR B6HS. And try try again....

Barring any compression issues, it sounds like your getting plenty of fuel for it to run.
 
I had same problem take your air filter iff they make it to where you have your choke still on also try starter fluid or wait till fuel evaporates but.your engine is fine u have juat a simple issue thats all as long as u have compressio. And hr head iant leaking look at ur magneto but just.cause u have spark dont mean it will turn over if just a lil oil gets on spark plug get a new one mine started after that
 
I had the same problem to keep it running i had to keep pushing the primer button to get home got home took out thottle needle and lookin the whole brass nut/jett came loose like wasnt attached open carb bowl screwed it in bike ran perfect
 
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