2 stroke not starting

**GrayWolf** · 27th May 2012, 18:36

Was the bike standing a long time before the rebuild?
is it a high miliage rebuild on a bike that was 'in use'?
If standing for a long time maybe the crank seals became dry? Or if an in use higher miliage one.. then possibly the top end rebuild has put extra 'pressure' inside the crank cases and caused a blow by on the seals? Either would end up with fuel/air getting 'through' but extremely lean mixture..

**bogan** · 27th May 2012, 18:39

Originally Posted by tigertim20

yeah, thats what the startings were.
I asked because the shops are closed so I cant go buy a new plug right now, what I CAN do right now though, is tinker, so thought it was worth asking if id overlooked anything else I could fix, seems the general consensus is no, it will just be the plug, so now I have to sit, wait, and twiddle my thumbs until tomorrow after work!

I've had some good experience with cleaning up fouled plugs, bit of turps/petrol/acetone and a brass wire brush, then some fine sandpaper on the ground strap and electrode. Might have just been excess oil form the rebuild fouling the plug, get it running and rev the tits off it!

**tigertim20** · 27th May 2012, 18:42

Originally Posted by Mungatoke Mad

A 4 STROKE

I have two of those in the shed as well, and they bring enough problems of their own!

Originally Posted by GrayWolf

Was the bike standing a long time before the rebuild?
is it a high miliage rebuild on a bike that was 'in use'?
If standing for a long time maybe the crank seals became dry? Or if an in use higher miliage one.. then possibly the top end rebuild has put extra 'pressure' inside the crank cases and caused a blow by on the seals? Either would end up with fuel/air getting 'through' but extremely lean mixture..

I dont really know to be honest, it came to me from a couple of young guys who I dont think were too kind to it (you can see my build thread for more info in that regard) so I dont really know.

In all likelyhood, its just the plug, which I will try and swap out tomorrow, and hopefully it fires up and problem solved.

If it ends up being much more complicated than that, Ill probably get fucked off and sell it as it is, my circumstances changed recently, and I can no longer afford to throw large chunks of cash at toys at the momment

**RideLife** · 27th May 2012, 19:20

Still useing 91 octane?

**tigertim20** · 27th May 2012, 19:35

Originally Posted by RideLife

Still useing 91 octane?

yes, should I not be?

**RideLife** · 27th May 2012, 20:35

yes, 91 usually helps two strokes start easier in my experience. Just checking you hadn't just made an octane change.

**5150** · 28th May 2012, 09:36

I had a similar issue with my old CR250. Same thing was happening. Every time I threw a new plug at it, it would start and run for a minute or two and die. Went through about 5 new plugs and still no luck. I pulled off and cleaned the expansion chamber which was dirty as hell. But what the main issue was, about a week or two prior I dropped the bike (slow crash in a wet grass) and broke the little perferated pipe inside the muffler (the one that the packing goes around) The packing moved and basically clogged up the muffler. The effect was similar to sticking the old potatoe in the pipe and bike could not breath out.

So to cut long story short, pull your expansion chamber off. Make sure it is in good and clean condish. Do the same with your muffler. Repack fresh if necessary and make sure there is nothing brocken or foreign inside.

**Fast Eddie** · 28th May 2012, 14:00

Originally Posted by tigertim20

If it ends up being much more complicated than that, Ill probably get fucked off and sell it as it is.

holla at me when its sell time haha

u can clean up old plugs aye shouldn't need to buy a new one.. but a single plug is pretty cheap.

if it was going before the wiring in of an hour meter and not after, maybe something happened there.. although if its sparking n shit.. one of those gay things eh

good luck

**jasonu** · 28th May 2012, 16:48

Originally Posted by tigertim20

have a slight issue.
Bik just had new top end, and has been run three or four times since the rebuild - each time only for about 5-10 minutes.
The other day I put an hour meter on it, and fired it up, no problems.

Next day, I wanted to take it out. I fired it up without an issue, and let it warm up, it was warming up fine for about 5 minutes or so, and as i was walking towards it to get on it, it died and wouldnt start.

I have tried removing the spark plug and kicking it over in case it was flooded,
checked the plug (which was new with the rebuild) and it is clean
spark is a strong blue spark
pulled carbs apart and cleaned and rechecked float height

still wont start

tried whipping the plug out and throwing some fuel down the hole and plug back in and kicking it over, - no go

just pushed it to the top of a big hill and tried to bump start it coming down, to no avail.
The best I managed coming down the hill was it would fire once every 10 or 12 revolutions.

what am i missing here?

1991 CR 125

http://www.youtube.com/watch?v=G-tCIRJH9p0

**Parlane** · 28th May 2012, 17:19

Is your battery all good?

Don't get me started on battery problems >: (

**F5 Dave** · 28th May 2012, 17:21

And here's another Turkey (with all due respect hehe) Its a CR! if you don't know. . . , Sheesh!

**Kickaha** · 28th May 2012, 17:22

Originally Posted by Parlane

Is your battery all good?

Don't get me started on battery problems >: (

CR doesn't have a battery, here's another vote for a new plug, it's always the first thing to change when a two stroke doesn't go properly, dunno what it is about them but cleaning just doesn't seem to work as well

**pete-blen** · 28th May 2012, 17:41

did you get your fuel mixture right ?..fuel oil ratio
Has the oil started to separate & sitting on the bottom
of the tank?
Reed valves closeing..they do lose there memory and don't
fully close after time..