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Any 2 stroke experts in the house?
mookaloid - 2/3/12 at 10:53 AM

Hi folks

got one of these Description
Description and it wont start

I have changed the spark plug and put fresh fuel in but no joy - worse than that I have blisters on my fingers from pulling the cord

Any suggestions please?

Put it in the bin and buy a new one cos it's an antique might well be the answer here

Cheers

Mark

wilkingj - 2/3/12 at 10:59 AM

Have you checked to see if you have got a spark?
Have you tried a different plug ie its breaking down under compression?
Is there any compression?

Is the petrol fresh?
Have you tried it with a squirt of WD40 in the carb inlet or a whiff of Propane or Butane from a blowlamp (with no flame of course )
I have often tested old engines that have been standing for a long time and the fuel has gone stale, or the carb is blocked.
The Gas in the Intake gets round all those issues and proves the engine will run.
Just dont do it for a long period, as there is no lube oil in WD40 or Propane / Butane, after all it is a 2Smoke .
Its a good check, we used to do this at my mates jetski business, as its simple to do, and bypasses all the fuel system.
If the engine fires up, then check the fuel system.

Daft Q's really...(sorry)

Just my 2 Reils worth.



[Edited on 2/3/2012 by wilkingj]

r1_pete - 2/3/12 at 12:55 PM

You have primed it haven't you? there is usually a plastic squishy bulb which you pump until it goes hard (oo er missus) to pressurise the fuel, exhaust heat keeps it pressurised.

MikeRJ - 2/3/12 at 01:10 PM

quote:
Originally posted by wilkingj
Just dont do it for a long period, as there is no lube oil in WD40


There's plenty of oil in WD40, probably more than a 20:1 petrol/oil mix, though how suitable it is for a 2 stroke is another matter!

Start with the obvious - is there a spark, and is fuel getting through (does plug get wet)?

JAG - 2/3/12 at 01:19 PM

Check;

Is there fuel getting through? does the plug get wet if you try to start it? If you turn the engine over does the air coming out of the exhaust smell of fuel?

Is there a spark? Take the plug out, earth it somehow and then turn-over the engine - do you get a spark?

After that I'd probably take the carb' off and just check there's no old fuel residue blocking any jets. This is most likely if the engine runs on pre-mix fuel/oil and has been standing for a while. Give it all a good clean inside and put it back together and try again.

Next check how the spark is generated; CDI or magneto type ignition? Magneto's have points and adjustment or lack of can lead to no spark.

Keep plugging away (pun intended) like this and eventually it will probably fire. Two-strokes are such simple things it's unlikely to be broke beyond repair.

My chainsaw (similar size and age) was a skip find - but a little bit of work soon had it running and it's now been a great tool for over 10 years

Peteff - 2/3/12 at 01:22 PM

Top handle saw with no chain brake, don't start it is my recommendation.

RichardK - 2/3/12 at 01:39 PM

Yeh as said,see if you can chack for compression or just break it down and pay special attention to the carb using carb cleaner and an air line a thin wire.
About the only thing you may struggle with is if the crank seals have perished and you no longer have crank case vacuum, everything should be easily spotted when apart.

Fetch it round and I'll have a shifty at it

Cheers

R

MikeRJ - 2/3/12 at 03:31 PM

quote:
Originally posted by Peteff
Top handle saw with no chain brake, don't start it is my recommendation.


Good point - not the most user friendly of machines.

mookaloid - 2/3/12 at 04:45 PM

ok

It has a spark - brand new plug fitted today

it has compression

fuel is getting through because it comes out of the exhaust after several pulls. - I have stripped the carb and it looks brand new certainly not blocked in the jets

there's no primer.

Can't see any points - are they under the flywheel cover thingy?

Crank seals might be shot but without stripping it down I can't tell

Perhaps you could pop round Rich and have a look?

RichardK - 3/3/12 at 11:56 AM

How much compression, min for me would 130 ish psi?

Not coming round to yours,right dodgy area,blokes in balaclavas wanting to rob you

When you moving out?

Cheers

Rich

batteredoldsupersport - 3/3/12 at 01:44 PM

I'm new here and no 2T expert. However the usual snag at this time of year is the carb bunged up with stale oil and fuel. Before you start stripping it down you can often get them going by fitting anew plug as this will be gummed up too. If you can't get a new plug take it out and give it a good heating in a gas flame, it burns the crud off and this sometimes helps.

David Jenkins - 3/3/12 at 04:49 PM

Getting the plug really hot, putting it back while still hot and pulling the starter is always worth a try.

I hate 2-strokes - they're fine when they work, but absolute bar-stewards when they don't, especially if they've been flooded at some time.

owelly - 3/3/12 at 05:47 PM

If there's a spark, the flywheel could have moved on the crank. Woodruff key failed or some just grip on the taper. Plug wet or dry?