Newbie SFC 1000 doesn't start

When was the last time it ran ok?
Maybe it sat for months or longer and the carbs are gummed up inside the float bowls.
Maybe the previous owner started it ok but that could have been a long time ago.
Also, try draining tbe tank and carbs and adding fresh fuel.
I bought an XL 250 once that would not start.
Turned out the previous owner had pissed in the fuel tank one night when drunk.....
 
"I bought an XL 250 once that would not start.
Turned out the previous owner had pissed in the fuel tank one night when drunk".....!!!! :o :D :D 8), lol... funny as fook that 8)
 
Having no filters and a"sports" exhaust shouldn't matter at this stage. It's a big old beast, a Laverda triple. Pretty crude.

FWIW, "pumping" the throttle shouldn't be necessary either under normal circumstances,  though might be worth a try in your situation. Only a little though. The Dellortos will chuck a lot of fuel down if you pump a lot.

But TBH, I can't recall ever actually flooding a triple. Fouling the plugs once started, yes, but not flooding it.

You should be able to get some kind of "bang" on choke & a closed throttle.

On the standard ingition you do need a pretty healthy battery as if the voltage drops, the engine will turn over (slowly) but the ignition won't spark.

But if you've got a spark and the engine is spinning over and, as you say, you get "wet" plugs....something should go "bang".

Take a step back, clean the plugs, check the fuel is on, fully charged battery (it shouldn't sound "tired" at all when you spin it over), 1/2 choke and hit the button :-)

Good luck. Happy to fly out to Samara to take a look if you're paying ;)

Must be a fascinating place to be living.



 
Grant said:
When was the last time it ran ok?
Maybe it sat for months or longer and the carbs are gummed up inside the float bowls.
Maybe the previous owner started it ok but that could have been a long time ago.
Also, try draining tbe tank and carbs and adding fresh fuel.
I bought an XL 250 once that would not start.
Turned out the previous owner had pissed in the fuel tank one night when drunk.....
Click to expand...

Ah! Good point. John L - with the fuel on, try just firmly tapping the float bowls with a piece of wood. Not too hard, but firmly. Could be one or more floats are stuck "down" and flooding the engine big style.
 
I removed the plugs again to see how they look after several attempts to start, and they seem very dry.

After I removed the left carburetor bowl and it looks very clean inside only petrol looks a little yellow.

I will empty the tank and all bowls and put new fuel inside tomorrow before my next try

I have to recharge the battery as well. Could this be a factor for not starting even when you use an external car battery as backup?

John
 
When you have a spark and the starter turns around quickly I?m almost shure it?s the fuel quality.
Better put fresh fuel in the bike. Today?s fuel quality is very poor and only good for storage for about a half year or so, because all the volatily stuf is evaporated and only the harder to ignite stuff (more high boilers) is in the tank / carbs after a long winter.
Also watch out while starting that you only put the choke lever say 2/3 and don?t turn the gas handle while starting because the choke circuit has it?s own air supply.
A few years ago I had the same in spring.
grtz and suc6,    Ren?
 
Once bought an old Triumph where the PO had put diesel in the tank and carbs for winter storage, forgot to tell me. I went through more or less what you are doing except kicking it over hundreds of times,until I realized I didn't smell gasoline, then the light came on!

Stu
 
Finding a spark is encouraging.

I presume you've checked that it has compression. If not, it would be worth doing. Engines need 3 things to fire - a spark, flammable mixture, and compression. You've got the first, working on the second, but haven't mentioned the third.

If the bike has been sitting for a while it could have rusty valves that are not seating properly. I recommissioned a 3C a few years ago that had been sitting unused for years. It had zero compression on 2 cylinders and 5 psi on the "good" cylinder. It was just poor valve seating due to dirt and rust on the valve seats and stems. I whipped the head off and cleaned the valves with a wire brush, then lapped them in by hand with grinding paste and the compression came up to over 100 psi on all cylinders, which isn't great but was enough to get it running. The piston rings were probably gummed up too, but I figured they'd come good with a bit of use. After a few hundred km, compression was up to 150 psi, which isn't bad for flat top (low compression) pistons. The bike has probably done around 10,000 km since then and is still going strong.

Let us know how you get on after draining the carbs and filling with fresh fuel.

If no success, you could give it a whiff of Aerostart or whatever the Russian equivalent is. In Australia it's called "Start ya bastard". That stuff doesn't need much compression to get an engine running. Hopefully once you get it running and warmed up, anything like poorly seating valves or gummed up piston rings will come good. Might be a good idea to change the oil after a the first hundred or so km.
 
"Engines need 3 things to fire - a spark, flammable mixture, and compression."
And don't forget timing!
But compression is a great point D-man, oiling up the cylinders wouldn't hurt. How long has it been since the bike was running?
 
Cleaned the carb bowls today. Fuel looks ok but down below floats some kind of residu like someone spit in it. Can I reuse the fibre seal/ring?

I will empty the tank tomorrow. Is it recommended to also remove the petcocks?

I am planning to try with fresh fuel before a compression test since I have no access to correct tools.

John
 
You can re-use the fibre seals if they are still in one piece.  They often part themselves when un-done.

Best to remove the petcocks while you're at it, lots of crap accumulates at the filters.  Also gives you the chance to get out any water that may have accumulated at the bottom of the front "flaps", these do show a tendency to rust through if water is allowed to remain for a lengthy period.

The petcocks have a LH thread, the tank stub RH.  Hold the petcock with a spanner and turn the hex nut only, should find a fibre washer sitting between petcock and tank within the nut.  This can also be re-used if it comes out in one piece.  If you only loosen the nut and screw out the petcocks, the filter may remain stuck in the tank stub, jammed by the paint chips and rust packed around the filter gauze.  Sometimes a pita to get out by themselves.

piet
 
Hi, As mentioned it would be good to remove the petcocks and I bet you will find a gel on the filters , this is mondern fuel as the fuel ages it starts to seperate and one of the things is this shit gel. Depends on which fuel and how much rape oil is in it.
Regards andy
 
I cleaned tank, petcocks and bowls. All really dirty like you predicted. Then I tried to start with 1/2 and 2/3 choke and support from my car battery.

Nothing happened, not a sign from fuel being ignited until after several attempts a very very loud explosion from the exhausts.

My heart still beats 200 or so...

and I never used the throttle

John




 
Did you replace the fuel?
Do the float bowls fill with fuel after turning on the fuel taps?
Do the taps flow enough fuel?
Once you have tried to start it are the plugs wet or dry?
Have you tried removing the plug caps and cutting 1cm off the HT leads and screwing the caps back on?
 
Forget to mention: filled-up with fresh fuel.
Bowls are full and fuel flows well through petcocks

Didn't have a look at the plugs. I didn't feel very comfortable after the explosion...(inside the building)

In the past when you used to much choke or throttle with old carburetor cars (overflow of fuel), the trick was not to use the choke anymore and apply full throttle (not moving) to have the cylinders breath again. Most of the time it then started with or without some backfire or fuel in the exhaust to ignite. Could this be the case?

Don't like backfire without air-filters attached.

John
 
That has worked for me with flooded dirtbikes after a crash. How long has it been since it ran, actually seen running by you. Have you changed the plugs,
tried Starter fluid, Either . Not much point in bump starting it without confirming spark on all 3.
 
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