Guys......I was chomping at the bit all the way to the shops to fetch my air filter only to find out that they didnt have any - practically reduced me to tears.
Hopped online and bought one last night, received the email earlier today saying its been dispatched....praying it arrives tomorrow !

This evening Im going to fit the carb, tighen up the plug.....check the air snorkel for rags etc, then wait out the delivery .

Are there any tips how best to get the air out of the fuel line when reconnecting the carb ? - or do I just fit, open the fuel tap and choke...and hope gravity does the rest ?

In addition....Oothef, haha....are you kidding ? (or not? )

Seems a good way to lose friends...

Also....even though the air filter housing has a mesh over the pipe to the carb intake port....is it safe to run the bike without the filter (even to check its working?) - Id need to ride the bike as that is where I was experiencing the problems (only once gears engaged and me pulling off)

Lastly, great idea.....once the bike is up and purring.....Ill work my way around and give it a service.....loving this, learning plenty!

Will be back with an update once the filter arrives......fingers crossed !!
Thanks for all the help..!!

Good luck

You guys are LEGENDS !!

It works !

I have worked it out - the hole(s) in the exhaust are blowing directly into the air filter snorkel.....need I say more .

I fitted the carb, I wedged some cloth between the exhaust holes and the snorkel.....the bike started 1st time, I rode 40 meters.....bike pulled fine .

Hoping the filter arrives today so I can fit it, and gonna make a plan to get a exhaust system replaced before we ride ANYWHERE.

Guys, thanks a bunch, I really enjoyed this !

PS - Was going to take the bike to the garage to get the exhaust replaced...or should/ can I do it myself ?

You've got this far......The worst thing about exhausts is that the nuts have a tendency to seize on the studs in the cylinder head, if you are going to have a go, get some quality penetrating oil and give them a good dose, leave to soak then give em some more and maybe some more! Use a good socket/ring spanner, preferably 6 point and see if they crack. Sometimes it helps to tighten them a fraction to break the corrosion, if they don't slacken easily watch it as the studs can sheer, sometimes running the engine to get them v. hot may help but watch it cos the exhaust will take your skin off! Having said all that they may come off no bother......
Make sure you get a new gasket with the exhaust and when refitting don't tighten tight until everything is nicely aligned so as not to stress anything.
You can do it.

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Just seen the "loosing friends"
friends as well as spark plugs have to be tested, after the shock you can usually run faster and further than they can, so long as you are not laughing too hard to concentrate on your evasion techniques.
My first encounter with high tension voltage was as a kid, I started one of my dads lawn mowers and it went on to full bore and I could not stop it! I pulled the HT lead off and was possessed by an evil indescribable power until the effer finally stopped and I walked away with a nonchalance I didn't really feel.
Cartoons have it off to a tee

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Thanks Oothef...will be sure to pick one of my tub mates ! - haha

Been at the bike again....and got a few thoughts

- To check compression without a gauge......at the risk of embarrassing myself. I hear placing your thumb over the plug hole and pressing the starter, the compression should blow your thumb off the hole. I presume this is because the stater motor turns the engine, causing the piston to move resulting in the desired compression one is checking for ?
Also....the piston would only create increased pressure around the plug and never a vacuum (across the 4-strokes) ? - ie: your thumb would not get pulled ? and this is because when the engine is on top dead center on the exhaust stroke, both the inlet and exhaust values are open simultaneously for a moment...so no vacuum (and stroke 2, top dead center on compression....is obviously "compression" ? - apologies for the ignorance.

- When one checks this....what is done with the HT lead (?) and spark plug ? - is this left with the plug attached and resting against the bike ? - or plug removed ?

- 3rdly.....Seriously !! - How do you check the plug for a spark...without me getting a shock or offending a mate ?

Thanks for the info on removing the exhaust system. All went ok, took a bit of heave-ho but the header holts came lose. The big problem I had was trying to seperate the header from the muffler (to remove the system from the bike chassis)....which I couldnt do, so I had to take the neanderthal approach of breaking off the muffler at the weakest, most rusted point and sliding it all though...it worked.

XR125 exhaust systems also appear fairly scarse online. Ive ordered one through Honda (will be about GBP180) with a few bits and pieces....gaskets, clamps..)...seems ok to me ?

Odd question....I could not find the header gasket on the exhaust Ive removed ?? Could it be that the gasket has COMPLETELY changed shape and is almost "merged" with the exhaust port vent ? - Will it require some muscle and screwdriver to remove ?

Hoping to receive all the bits and pieces end of this week so I can get into part 2 of my Mr Fix-it course .

Yet again.......thanks all for all the help !!

I don't know that the thumb compression test really tells you much as low compression will still push your thumb off, but try it.
If you leave the plug in the cap put it out of the way, or rest the threads on the engine where you can see it and you can watch for the spark, a strong one is fat and blue.
Is there a lot of carbon in the exhaust port? try scraping it off carefully with a small screwdriver or similar. Gaskets tend to be compressed in, but you can see the joint with careful inspection, they often take some persuading out.
A thought... Keep it clean, whether just the plug out or a full strip down don't let muck enter as it will lead to wear.
When replacing the exhaust use anti-seize/copperslip on threads and joints, it'll make it easier next time(maybe new nuts?).
If you're going to get into spannering on your own bike/s get a manual, they can save a lot of blood, sweat and tears and have all spec. for servicing(and everything else). Valve clearances need checking.
I've used David Silver for Honda spares, always been good for me.
(not recommending, but I've started bikes up with no exhausts on, just for the terror of it! just start, rev rev n stop brill!)

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Hey guys, Im back.

Took a while to get all the bits....but now fitted and running !

If I give the throttle a burst from idle, the revs hesitates as if it may want to stall...but then climbs perfectly. This didnt happen pervious to the exhaust replacement, new airfilter etc..

Could this mean the pilot screw needs an adjustment ?

I will take it for a ride tomorrow to give it a bit of a stretch.
Cheers

The slight hesitation is not uncommon on some older carb bikes - they were set a bit lean for emissions

Get the bike well & truely warmed up and then try - and if it still stumbles on initial pickup, play with the pilot screw.

If the range of 0 - 4 turns doesn't cure it, you may need to go up a size on the pilot jet :confused1:

This problem can be more pronounced on the bigger singles which seem to hesitate/stall due to their size & flow characteristics like my XL500R.

Pigford.....took the bike for a quick spin, did a few blocks and the bike appeared fine, no hesitation at all. Perhaps it just needed a good rev....hadnt ridden it for 3 weeks.

Im off to Cornwall this week on my xt600, gonna give the panniers, tent etc a bit of a shake.....once Im back I will continue on the 125cc service....oil change, brakes etc..cant wait, this is like a drug !

Thanks for all the help....chat soon

PS - Im amazed that we got the bike to start, let alone run properly.....once the carb was in my kitchen in a bowl of petrol, I thought that it was all over...never to start again....haha, what fun !!

Pleased you're up and running again, it's great when it all works, the real test is when it doesn't..........How I set carbs (on singles) get it warm, set tick-over then screw mixture screw in and out slowly, find fastest tick-over point, re-set tick-over and try again. If it's already running O.K. note how many turns out the mixture screw is before you start then you can always revert back to that if there's no improvement.
Have a good shakedown in Cornwall, always liked Crantock just outside Newquay, dunes, beach, river...Enjoy

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