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Discussion Starter #1
Hi all,

first of all thanks a lot for reading. I just joined the forum to try and find some help on some issue:
I've got this Suzuki EN 125-2 bike which I haven't used in a long time (2years). It has been kept in my back garden for all this time and I'm now getting it back on the road.
I have had to change the steering lock after somebody tried to nick it. so, new ignition.
I changed the battery, and the electrics work ok: all lights work fine, the fuel gauge works etc.

As there was some fuel left in the tank I tried to start the engine and failed. I filled the tank halfway, and still the engine won't start. Using the choke, the engine starts straight away, but then the idling is not stable at all, it judders and the rev fluctuates. Sometimes the engine dies off if I put the choke back halfway.

If I try to rev up the engine to keep it running, the rev drops and it dies off immediately.
I checked the air filter, and nothing looks wrong / obstruated.

So reading a couple of threads here and there, I found there could be several causes:
- something happened to the fuel as the bike stayed unused that long and something got blocked
- the spark plug is dead
- the new ignition does not deliver enough to either start without choke and / or maintain the engine running

I don't have any experience in car / bike mechanics and only have a limited understanding of how it all works, so thought I'd ask the experts opinion before I start taking things appart :)
Also, I cannot really take it to a garage as it is not MOT'ed / Taxed / insured

thanks in advance for your help,

Vince
 

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few things
1st how long are you leaving the choke on for. from a cold start ( sitting more than a few minutes) you should leave it on for a min or 2 before backing off ( till the engine warms up). its not just a method of getting the bike to start.
if the bike starts at all then the ignition switch should be fine ( barring a loose wire)
plugs are cheap (ensure correct gap). and check your air intake/filter for obstructions/dirt.

before you do anything major.
drain the fuel, and clean the tank (swishing some alcohol around in it and drain again) and properly dispose of waste fuel/sludge
clean/replace any fuel filters and check petcock (also tends to get gummed up.)
fill the fuel tank and add 2 oz of carb cleaner (b12/gumout). repeat for a couple of tanks and at least once every few thousand miles ( you can use the oil change schedule).
run the bike for a little. let sit for a bit then try the bike again.
you should also change the oil/filter. another fluid that doesnt like being left to sit for years.
check your rubber parts for cracks/tears.
get street legal.
 

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Nice job slozomby.

I suspect that it is bad gas (or petrol, rather) that is the main problem. Ditto on the oil and filters being changed. Could have rust in the tank now, if it sat that long in the garden I would almost bet on it.

All of these things are great ideas, and at the very least will be a good starting place. If the problem isn't anything that was mentioned, just know all of those things need done regardless. Good luck.
 

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P.S.

If you use some fuel stabil next time it is going to sit for more than a month, you probably won't have this problem again.
 

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Discussion Starter #6
Hi guys,

thanks a lot for the replies and the good advice! I've just got a spark plug socket so will check that first, then look into the filters and clean the tanks as suggested...
Are the things mentioned requiring a lot to take appart on the engine? As I mentioned earlier I'm ok with all the basic stuff (changing plugs, cleaning air filter etc) but start getting lost once it becomes a little more complicated...

thanks for the tips anyway!
talk soon
V
 

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The spark plug and ignition are fine- plugs do not go bad just sitting and if the ignition switch was bad the bike would not crank. This is a very, very, easy one: the carb needs to be cleaned. It is as simple as that.

A gummed up carb is found on basically 100% of bikes that sit for a time with gas in them. Gasoline/ petrol breaks down into a varnish in only a few months, so while the bike was sitting for two years a LOT of varnish built up, clogging the small internal passages, and the jets. They do not flow enough fuel being partially clogged, so when you either push in the choke or rev the engine more air gets in but more fuel does not, so the bike runs poorly because the air-fuel mixture is too lean.

The varnish most likely not only did a number on the carb, but also gummed up the inside of the fuel line, fuel filter, and the fuel tank. Remove the carb, take it apart, and completely clean it, or as you have little mechanical knowledge let a trained mechanic do it. Replace the fuel line, and the fuel filter, both of which are very easy to do yourself and very cheap, so it is not worth trying to clean them. Visually inspect the inside of the tank as well as you can, and it it looks really bad rinse it out and put in fresh gas, if it looks pretty good then just put a some 'in the tank' carb cleaner in there and in the next couple tanks of gas.
 
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