Hard/No Starting

[STEVENM63]

Okay, I'm determined to get my 250 nc on the road this summer, but first I have to get it to start and run. With Bob's help I have had it running briefly last summer, but I had to kick and kick...and kick, even when it was warm. Now that I have some time I'm working on it again. The way it stands now, I'm not getting it to fire at all. I do have white/blue spark (new plug), but it won't fire even with starting fluid.

What should I check next? I'm in need of at least a few puffs of smoke to preserve my enthusiasm LOL.

Steve

[JimF]

I'm no expert, but you have spark, you have fuel (at least when you spray starting fluid in) and if you are feeling the resistance of compression when you kick you have all the ingredients you need to at least here the popping sound of an engine struggling to start.

So my thinking would be that one of those ingredients is missing. The most likely culprit is the fuel. Are you sure the carb's slide is up and out of the way of the intake tract when you spray the starting fluid in?

On a similar note I had a similar hard starting issue when I was lighting up my first Ducati 250 for the first time. I had the carb slide too high when it was at rest (no throttle twist), and so the carb was well off the start/idle circuit. I figured it out when I had the rear wheel in a stand off the ground and I spun the wheel as hard as I could. The engine fired up and immediately ran at several thousand RPM. Duh! It all made sense then. I lowered the slide at rest and the bike idled and starting became easy.

[STEVENM63]

Okay, I just did a 40 kick workout before lunch, LOL. Jim, I made sure that the slide was down (I readjusted the stop to make sure). I did get a barely perceptible cough on a couple tries, but nothing else. I opened the throttle and checked the intake, viewing through the carb, and saw gasoline vapor. I also removed the plug and saw a fog of gasoline vapor in the cylinder through the plug hole. While I had the plug out, I rechecked the spark and I was still getting spark.

What am I missing? Could my timing be off, allowing some or all of the fuel mixture to escape before the plug sparks? That might seem logical, except for the fact the the engine has run before (albeit at higher rpms and wouldn't idle)

Steve

[JimF]

Geez, I don't know. Could you have poor/leaky compression? Could the timing of the spark be at the bottom of the piston travel rather than the top?

Somebody much smarter than me (that's pretty much everyone else on the forum) needs to chime in.


Jim

[amartina75]

I'm not sure what all you've done to the bike. have you checked the compression? or the ignition timing? did you have the timing gears apart at all or the advance unit out? if your advance unit is off by 180deg you will not be getting spark at the right time. same goes for your oil pump gear if it's not lined up your spark will be off.

if you are getting fuel and you are kicking the bike over 40 times (in that I mean using the kickstart lever to rotate the engine) you are wasting your time and energy. after several attempts of starting your plug would most likely be soaked with gas. if it is not you might have a fuel problem.
be careful with the spark plug threads if you are pulling the plug often they are prone to stripping.
I find it easier to get a bike started for the first time with the slide set higher then it would be at a normal idle. it's easier then holding the throttle open slightly while you are kicking the bike. once you do get it started then adjust the idle down.

you should start with the basics one by one, if you are not getting a soaken wet plug with all the kickstarting you are doing I'd start with the carb.
good luck

[STEVENM63]

Well, maybe 20 times,lol. Thanks, I will check timing, advance and compression. Strange because I was able to start it before and take it on a short ride through the neighborhood. I need to pick up a degree wheel and some other supplies to check the timing. On that note, Ducati doesn't make it easy to set these bikes up. I can set the timing on my Hondas visually on the side of the road. Anyway...

[amartina75]

it only takes a few minutes to check your compression, so there is no reason not to do it first off.
if you tried starting the bike 20 times even you should be flooded as hell, so if you are not then I think you have a fuel problem. if you have never touched anything that would change your timing then I would expect it to be close enough to run, but should still be checked if you never have.
as for starting the bike you should position the piston just past TDC before kicking hard.
I do this by slowly pushing down on the lever until the compression builds and makes it harder to go any further.
then move the lever down another 10 degrees or so
then reset the lever and kick hard and all the way through.
if you are not following a similar procedure then you will have trouble getting the bike started

[STEVENM63]

I will check compression as well. One question with your starting procedure. I move the kick start lever until I fill the resistance of the compression stroke, however, I don't move the lever the additional 10 degrees that you refer to. How would that affect the ability to start? Just curious.

[amartina75]

you are wasting some of the energy you are using to kick the bike over because you are starting before TDC and have to get past the built up compression first. that is probably not your problem but still would be better to rotate the engine past its compression build up before kicking

[Nick]

Please stop jumping up and down on the kickstarter, you're only going to ruin the mechanism. Use push starting only until you get it running properly.

Your carb is almost certainly messed up (low speed circuits probably plugged, at the least). Strip carb completely, soak all metal parts in lacquer thinner — not solvent, not carb cleaner, not brake cleaner, but lacquer thinner!. After about an hour blast clean with compressed air. Check that all jets are clear, etc. Refer to manual for information.

Or, try another carb. Or, pay someone who knows what they're doing to rebuild your carb or show you how to set it up, it will be money well spent.