RS125 Help - Won't Run After Carb Clean/No Fuel to Barrel

sinedtomuch · Banned Joined: 25 Oct 2013 Karma :

Hey guys first time poster, expert leecher ha

Right so I decided to clean my carb out this was because fuel wasn't getting into barrel and everytime I wanted to go for a ride i'd need to take spark plug out, grab fuel hose poor some down and it would fire and run as normal.

So I cleaned the carb out to try and amend this. Removed all jets etc used good carb cleaner, assembled again and it still wouldn't fire lol. So I added fuel into the barrel and went for a short ride which turned out to be really short as the bike wouldn't rev past 4k and whenever it hit 4k it would die if I didn't pull the clutch in. So I'm trying to get back home going at walking pace as the bike has no power what so ever now eventually having to push it up a hill.

The only thing I can think off is I have assembled it incorrectly but I have double checked it and everything looks fine.

Any thoughts before I totally rage out and destroy it?

Cheers guys

sinedtomuch · Banned Joined: 25 Oct 2013 Karma :

Things I have replaced thus far

Battery
Spark Plug BR9EG (it is a full power RS but halfords only stock this)

P. · Red Rocket Joined: 14 Feb 2008 Karma :

Buy a BR10 from ebay.

Remove the carb again, also remove the fuel hose and check for it being perished, any filters?

sinedtomuch · Banned Joined: 25 Oct 2013 Karma :

Removed carb again today, it seems the float chamber is just storing fuel as it was full once I disconnected it. Ive now got a BR10 and its in just now, waiting on the battery being charged atm.

I've just bought a pipercross air filter and cleaned the fuel filter. Both are very clean.

Just waiting on battery charging to test

P. · Red Rocket Joined: 14 Feb 2008 Karma :

Don't user that air filter, just grab a stock one and make sure you are using the stock airbox.

sinedtomuch · Banned Joined: 25 Oct 2013 Karma :

Right I changed the plug, took the carb out cleaned it again, went for a short ride seems to be a lot better. A big flat spot at 5-6k tho. My CDI bridge is snapped and I'm using the second top clip on the throttle

P. · Red Rocket Joined: 14 Feb 2008 Karma :

Can you ride through it with a steadily opening throttle or are you trying full throttle?

sinedtomuch · Banned Joined: 25 Oct 2013 Karma :

That problem seems to have been solved when I changed the plug. It now rides as normal besides the flat spot and the fact it doesnt start without fuel down the barrel

sinedtomuch · Banned Joined: 25 Oct 2013 Karma :

The BG9 plug was only a few days old and was covered in black carbon shit but it wasn't wet, completely bone dry. Does this indicate running oil rich?

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

Suggests it is rich, probably fuel wise. But if you have been doing lots of short runs then it might well foul up a plug rapidly. A 10 will likely foul up more quickly than a 9, and I wouldn't expect a 9 to give the problems you were having (rather issues when thrashed with the plug over heating).

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

sinedtomuch · Banned Joined: 25 Oct 2013 Karma :

Anyone venture a guess as to why fuel isn't flowing into the cylinder with me manually doing it? Because I'm totally stumped.

I've checked the inlet manifold for leaks there were none, tested with easy start spraying the manifold whilst engine running looking for rev gains, there were none.

Fuel is flowing into the carb, i'm not sure how to test the carb to see if its distributing fuel properly. The needle in the float chamber isn't stuck as the carb as been overhauled fully.

And lastly, what notch of the throttle should the clip be on? Mine is on the second one from the top and its still coughing and splurting at 5-6k really pissing me off and probably drivers around me haha

nathan k · Spanner Monkey Joined: 28 Mar 2012 Karma :

What colour is the spark? (hold the end against the cylinder, don't shock yourself, and crank the engine)

Is it a air box you're using? Race filters need up jetting by roughly 10 sizes.

sinedtomuch · Banned Joined: 25 Oct 2013 Karma :

Well i've replaced it with a new plug. I'm not sure what size of jets are in the carb atm as I only bought the bike a month ago and don't know if the guy upjetted or not. Is there a way to check what jets are in it the carb atm?

nathan k · Spanner Monkey Joined: 28 Mar 2012 Karma :

sinedtomuch · Banned Joined: 25 Oct 2013 Karma :

Its also worth noting I can't use the choke, If I was to use half choke it just cuts out therefore have to manually hold the throttle until warm.

God this list of problems wish I'd gotten a 4stroke haha

sinedtomuch · Banned Joined: 25 Oct 2013 Karma :

A slight update to worsen my mood a little,

So I changed the plug to a BR10, charged the battery, cleaned carb out fully adjusted float chamber. Fired bike up runs fine for a short while, go into third take it up to 10k RPM and it cuts out and won't start? There is a full tank of fuel and its set to on and does flow into the carb.

I have truly had it with this bike causing nothing but problems, spend more time trying to fix it and taking it apart than I do riding the bloody thing, if it wasn't so fun to ride I would have taken a hammer to it long ago haha.

sinedtomuch · Banned Joined: 25 Oct 2013 Karma :

update:

done a compression check, getting 140 PSI WOT cold engine so this is fine I assume?

spark is a small blue spark.

this would mean to me the problem lies in the carburetor.

Anyone care to back my theory up haha

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

Compression sounds fine.

One thing to check, when cranking over normally (with the plug in place) is it sparking? Use an inductive strobe light to check. If not then check the distance between the flywheel and the pickup. If that is too large then it won't trigger a spark properly.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

sinedtomuch · Banned Joined: 25 Oct 2013 Karma :

It definitely sparks when in place because when I pour fuel down the engine turns over fine. Only problem is I have to pour fuel down. Fuel flows into the carb but I can't check the fuel flowing from the carb into the cylinder

bypass2 · Spanner Monkey Joined: 12 Sep 2013 Karma :

when you took the carb of was there any or much petrol in the bowl. what are the float heights set at.try the myddle notch on the throttle slide clip.

sinedtomuch · Banned Joined: 25 Oct 2013 Karma :

Float bowl was full. I've adjusted the height now. It's now parallel to the metal when flipped. Waitin to try it out tomorrow

sinedtomuch · Banned Joined: 25 Oct 2013 Karma :

So now it won't even start with fuel down the barrel. I'm truly stumped.

bypass2 · Spanner Monkey Joined: 12 Sep 2013 Karma :

is the plug still sparking. have you tried bump starting it. you said its the full power rs so thats the one with the exhaust port rave valve would this stop it running if it was full of carbon or stop the petrol going to the barrel

Robby · Dirty Old Man Joined: 16 May 2002 Karma :

What have you done to the bike. Trying to diagnose problems like this is a difficult process if you've fitted silly jets or removed the reed block thinking it was restrictor.

If it won't start normally and the choke just kills it, and your carb is clean, I would be looking at what you have changed on the carb and setting it back to where it should be.

sinedtomuch · Banned Joined: 25 Oct 2013 Karma :

I was under the impression engines required compression fuel and air to fire. Compression test was done and came back all clear, added fuel down the barrel and the fuel/air screw is set at 2.5 turns out which is recommended. Only thing I can think of is the engine is flooded.

I cleaned the carb again earlier without adding fuel down the cylinder and plug did get wet so fuel is flowing again. The plug is sparking as I tested that before attempting to start it and its a fat blue spark. Put spark plug in and I can feel the engine is trying to turn over but never does. I did successfully bump start it earlier but its not running properly at all and cutting out when trying to take off.

Initially the only problem was the fuel flow only. Now its turned into much much worse.