Bike dying without throttle/idling

[RaptorJ]

Hey, first post. Just bought myself a cagiva raptor 125 2007 5000 miles, good condition.

I ran it out of fuel the other day, warning light didnt come on! started it a few times thinking it was engine troubles so must have really dried it out.

Now after refuelling it wont start, im a novice but im not completely useless. Iv checked the carb and jets and the filter in the carb, no blockage. Also checked fuel is flowing into the carb and from the fuel pipe which it is heavily.

Also checked the plug, a little sooty but sparking still. Annoying thing is, it bumpstarts fairly normally, and the bike then runs as normal when accelerating off. When coming to a stop without throttle it dies, or when trying to let the bike idle it quickly dies.

Admitidly the bike would often cut out when cold unless it has a lot of choke or is revved a little.

Anyway, any ideas guys? Im going to replace the spark but i dont see this making alot of difference really :S?

Peace and safe riding, Joe

[Matt-]

Welcome to the wonderful world of 2 strokes

Sounds nice bike with only 5000 on the clock...

So idling seems to be a issue at low revs.

First thing I would check now you have done all of the above is, the air filter make sure it's cleaned & sealed ok, also check for leaks between the air filter and carb on the manifold, get some WD40 & spray it around the manifold and see if it bubbles, if it doesn't its good you don't have any air leaks, also one thing I would do is clearing your cylinder, ignition on, fuel off, turn the throttle all the way back, and try & start it for about 10 seconds ( this will push any crap out you have in their )

Once you have done that try & start it as normal.

Good luck

Matty
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RIP jack (wheelie king), you will never be forgotten.
Current Bike's - Road Legal TZR 125 Pitbike, Aprilia SR50R 2010

[RaptorJ]

Thanks pal.

Yeah the bike been abit of trouble but to be honest I have learnt a lot from the bike going wrong because of all the research i have done trying to fix her.

I also kind of enjoy thinking of all the things that could be wrong and going through them. Just irritating when you've run out of ideas as to what could be causing it, and you want to take her for a ride.

The air box isn't as sealed as it could be I don't think, I could probably do a few things to get the box lid on tighter. Im going to give the filter a good clean and dry, and try running the crap out of the engine like you suggested.

But since the problem began I have like i said bump started it and taken her up and down the road surely this would have cleaned the crap out, someone suggested fiddling with the idle screw. Im also going to upjet all three jets to the correct derestriction size.

It just doesnt make sense though, the bike was running fairly well other then a few idling problems before, why would it go from this to not starting or idling at all just because I ran out of fuel when i no the jets are clean and fuels getting there?

It cant be a compression problem because when I got her going she rode at normal speed.

We even tried pouring a little fuel down the spark plug whole and sparking her but nothing. So we know the engines getting fuel and a spark, so the only other thing could be air. But why would running out of fuel suddenly stop air from getting into the engine when idling.

Only thing i could think of was the carb over flowing when trying to start her stopping the air getting through if this even makes sense.

Sorry for the complex reply lol as you can tell its frustrating me slightly but i'll try some of the things mentioned and let you know!!!

[Matt-]

Yeah it's very enjoyable as i have had load's of problems with my Honda NSR (simlour problem)

Spray some WD40 on the air intake manifold which connects filter to carb & also on the manifold where the carb is connected to the Reeds
if their is any leaks it will make idle higher and erratic.

Replace the jet's with de - restricted jets if it's a standard full power version, if it's got a aftermarket exhaust you will need to up jet further on standard de restriction jet's.

Adjust the Mixture & Idle jet as it say's in the workshop / Service Manual then with the carb fully cleaned, with also checking of the needle valve, make sure it's seating ok and the rubber is not split / damaged, also check float height & make sure floats don't have petrol / liquid inside.

Also even though it's running ok it could still have bad compression, anything under 100 PSI is BAD and will need a rebuild or ring's or what is damaged, little thing you can do if you can't get hold of a compression tester is stick your finger over the spark plug hole and if it blows your finger off it's ok " well not exactly " it should be over 120 PSI if i am correct, it will be due a rebuild soon anyway as 7000 Is top end time

Hope this helps & Good Luck

Matty King
____________________
RIP jack (wheelie king), you will never be forgotten.
Current Bike's - Road Legal TZR 125 Pitbike, Aprilia SR50R 2010

[RaptorJ]

My friend has an NSR hes been helping me out, he let me ride it hes de restricted everything but the exhaust and its dam fast when the revs pick up scared the hell out of me haha!

My exhaust is the standard one i think he said something about it being good anyway because of the straight downpipe cant remember exactly. I dont think this needs adjusting for the de restriction not too sure! Thinks its just three jets and the air snorkel.

I'll try the finger thing, to begin with though i guess i should get the compression tester at some point anyway. And I take it spraying the WD around the places you mentioned needs to be done with the engine on, have to find out how to actually get the engine started and idling first. Engine literally does not stay running unless theres a hand twisting the throttle back a little!

[WannaBeDude]

Or do what was advised on 125 thread you made.
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Jogging on, destination living.

[RaptorJ]

[WannaBeDude]

https://www.125ccsportsbikes.com/forums/index.php?showtopic=99358
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Jogging on, destination living.

[RaptorJ]

If you read the thread you'll see I'm asking what size fuel jet I should use, it's a different topic.

I asked them if they new about my starting problem and no one had anything to say on the subject they just gave me advice about de-restricting which i'm grateful for.

[Matt-]

Use the search option in " 125cc sports bike forum " just search jets after your bike model, if its standard you should be able to look in a workshop manual & see the standard de - restriction jets.

How're things, any more news ?

Matty

[RaptorJ]

I have ordered the jets and the plug there on the way, I cant do alot until they come but i was just going to take the air box out and clean the filter, it is wet.

I have just noticed though when tried to start it a sec ago alot of fuel dripping out of a breather tube from the bottom of the carb. I dont no if this is normal or not but I dont think it is?

When I took the bike apart the otherday i remember noticing that the tube had come of the carb so could maybe there was so much fuel flooding the carb that the pressure blew the tube of? hmm

[WannaBeDude]

[RaptorJ]

Well no I havent done any of this things, all the advice those guys gave me where about upjetting and what to do when i de restrict my bike, they said if you upjett do compression tests etc, and when i do upjet i will do those things im not going to ignore them

However I dont care about de restricting the bike at the moment, the problem is when i bought the bike it was running fine. I ran it out of fuel and now it wont start.

So im trying to get advice at the moment on what running out of fuel could have done to the bike to cause it to stop starting lol?

So once the bike is running normally in its standard restricted state, I will then start worrying about de restricting it. Get me lol. Im not asking a group of experts about one thing, then ignoring them and what they tell me to do and asking someone else the same question without trying.

I made that thread about de restricting my bike when the bike was running well, however my bike broke a few day after i wrote that thread?

Understand what i mean lol?

[WannaBeDude]

https://www.125ccsportsbikes.com/forums/index.php?showtopic=99132

So not a blocked jet issue then.

The carb filter and the fuel TANK filter need checking, also make sure you route the fuel line when you put the fuel tank down, as it sits in a grove, finger fuel line into grove, lower tank down crouched down looking and routing, once tank is a few inches from closed, let it ease down.

Put a new spark plus in, BR9EG or BR95EGV.

Also, did you ever undue the main jet bolt that was stuck - and did you check your floats in the carb are undamaged and working A ok.

Where is the carb needle sitting, what notch, is the choke working correctly.

Whats your batterry volt -

Just about eliminating things to fault find and know what condition your bike is in.

Make a new thread on 125 after you've done the above ... keep this one going aswell, but RB mito and Hevo etc, will have the checks and answer you need.

They wont bother helping if you dont do the things asked / checks.
____________________
Jogging on, destination living.

[RaptorJ]

I think I've come to the conclusion that the carb is flooding, fuel leaks out when I press the starter. And the engine only runs when the throttle is open and more fuel is allowed to exit he carb. When i try and let the bike idle not enough fuel is escaping and it floods.

Im just not really experienced enough to now find out what is wrong with the carb thats making it flood, iv looked at the float but i cant tell if its okay or not.

[WannaBeDude]

Lots of info inc pic and even vids of starting her will help lots and allow peeps to help.

I dont know how to fix um btw, just not to blow um up
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Jogging on, destination living.

[RaptorJ]

I'll get some pics up of the opened carb although i have to upload them to facebook then get them of there cause I have no computer lead for my phone! I just lifted the float up and down and it moved the little metal pin its connected to by a few milimetres when i lift the float up

I have cleaned the carb filter its fine now.

And remember the bike was running fine until i ran her out of fuel, the needle is on the second notch from the bottom.

Choke was working fine when I was starting the bike before all this happened. I have checked the spark and also ordered a new one already!

Its 2007 with 5000 miles on the clock my friend was said the condition seems excellent

That link you just posted is a thread I made just after i bought the bike, I took it to a garage and the jets were just blocked. Since then the bike ran pretty well, then I ran out of fuel and cant start it again. Think thats why we're getting confused lol!

[WannaBeDude]

As said above - FUEL TANK filter ? check that - check if you have an inline filter somehwhere on the fuel lines aswell - not standard but many stick them on.

Sounds like its flooding ... tbf im just trying to help you get the answers, can't provide sure fire answers like others here or on 125 can.

I use their help to not blow mine up etc, and have a chap that dont rip me off when he does work for me, which is why i use him more than needed.

Where are you in UK ?
____________________
Jogging on, destination living.

[RaptorJ]

Yeah i do appreciate it man, I work 5 or 6 days a week so I just wanted to check the obvious first and leave the difficult things till last. My stepdad hates me working on the bike like hes paranoid im going to get oil on the drive or something. I'll have a look for the fuel filter and check that, fuel is running freely as i have removed the fuel line from the carb and turned the tap on.

I live in kent, thanet. Ring any bells?

[WannaBeDude]

[Matt-]

[RaptorJ]

Yes I did have the carb apart previously to check the main jet size but we were very careful with it. I then put it back together and started the bike and it ran very normally i used it for a few days it was fine. Then a few days later as said i ran out of fuel, pushed her to a garage, filled her up and she wouldnt start unless i bumped her and rode her with alot of throttle, my friend then came over the next day, we didnt touch the carb and bump it again and found that the engine only stayed running when the throttle was applied.

We then cleaned the carb filter and jets none of which were blocked and that didnt solve anything

So gotta think what part of the carb could of been damaged by running the bike out of fuel thats now causing it to flood.

And nope, i have the restricted snorkel and the de restricted snorkel. Im running her on the smaller snorkel and the normal jets.

My pal just seemed to think that upjetting the idle jet would allow the bike to idle without throttle but that doesnt make sense as the bike was previously running fine with the normal jets.

If have read everything you guys have said so if i forget to repy to a suggestion im not ignoring it im just rushing between laptop and bike lol and writing very quick so sorry if im repeating myself too

[RaptorJ]

And yes it is perhaps looking like a float issue, the floats do not have holes in, and i will try to check they are measured correctly. I will clean the airbox, a dirty wet filter would be the cause of the bike idling poorly but doesnt explain why the bike wont even fire up at all iv been told

[jeddy11]

If you run it out of fuel then the obvious thing is its sucked some crap / shite into the carb or fuel tap filter etc...

All needs stripping and cleaning again even if you think it looks ok...
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Fuelly My Z1000SX
cbt 06/08/11 mod1 (second go) 01/08/12 mod2 21/09/12
Varadero Viking YBR125>Varadero125>ER6F>Z1000SX !!!

[Matt-]

Yes that would be a good place to start, on my NSR the float height was incorrectly adjusted allowing more fuel in which made it flood out if the air filter side of the carb, this fixed my problem the same as yours when I adjusted it

If its a foam filter get some washing up liquid, wash it out with soapy water then rinse fully and allow to dry,if it requires oiling then oil it with some light gear oil so its a little damp.

Good luck

Matty