Aprilia rs 125-trouble starting arghhh

[frenchy]

hi guys, my second post on here.

basically, my rs 125 wont start.
-if you try off the ignition, it makes a horrible sound and wont fire, so i bought a new spark plug although the old one seemed to be sparking fine, also replaced battery and ensured it was FULLY charged. still no joy. After many many bump starts, finally she fired up, bt then cut out, however this could be due to a lack of petrol etc...as i had removed the tank and used a squeezy bottle just to make sure petrol was getting through. All of the other electrics seem fine, horn, lights etc work.

Now even though it started after countless bump starts it doesnt seem to want to start again and definately not from electric start.

i removed the spark plug to compression test it, the meter didnt pick up a reading. i was turning the engine over by hand (would this have effected it) ? i wouldve thought i should get a reading, may be not all the high even if there was an issue.

When i got the bike it had been partially stripped and the previous owner had bought a car and lost the will to put it back together so the carb etc was all disconnected. (i reconnected this np). He claims he had redone the top end recently...

Soo, any help would be greatly appreciated it, dying to get it started, up and running to use for commuting to uni.

Any tips on how to clean out the carb etc too?




by the way, anyone have any info on getting insured on 'big bikes'....i was thinking of getting a gsxr 600 and having it restricted to 33bhp to be legal, bt previous insurer said they couldnt insure me as most young lads remove the restrictions straight after etc.

however, they would insure me on a gsx-750 for £650. (dnt really want a gsx though, much prefer looks and performance of gsx-R..all be it restricted)
and insurance for my rs125 is £250 a year.

[paulcdb]

might help if you posted in the right place... like maybe The Workshop

not exactly news is it?
____________________
Excersise is rubbish!
If your healthy you don't need it... if your sick you shouldn't do it.

[frenchy]

gd point, thanks.

[stirlinggaz]

hi,
definitely do a compression test, with a decent screw in tester (gunson one in halfrauds is good & cheap enough) as sounds like it wasnt rebuilt properly.
& return carb to stock settings, after cleaning it out & blowing through with compressed air. (take a note of what jets are in).
try running it with the air filter foam element out. (might as well wash it while its out) & stick a LITTLE fuel down the plug hole before starting.
rs's cant be a c*nt to start if they have been left sitting for a while, you could try some "easy start" or "start ya bastard" (excellent name)
are you saying it has a kick start? (only aprilia rs125 to have a kick start was the sp)
what is the "horrible sound" & where is it coming from? (might be the starter bendix)
what spark plug you using?
let us know how you get on,
cheers,
GAZ
edit : i know you said the battery was fully charged, but charge it up again & test it with a multi-meter, as voltage reading on LCD is notoriously inaccurate.
& every rs i have owned (had 6 or 7 now) needs a really good charge to start & have all been a bitch to bump start. (unlike the mito which will bump with a push off with both feet,lol)

[frenchy]

recharged battery with trickle charge just to make sure its definately full. ill follow your advice and clean carb, filter etc etc. also, the compression meter i used wasnt a screw in, just had to push it in, rubber bung on the end type thing, so couldve been losing compression through that too. im thinkng the top end was not rebuilt correctly.

My bike does not have a kickstart (annoyingly).

Just got the paperwork back from the DVLA and year of manufacture is 2000, not 2001 like i originally thought.

funny you should mention bendix, thats what i suspected. i think the little carbon bush or w.e it is has gone, or needs replacing at least. the start motor/bendix is where the horibble sound comes from, its hard to describe, its not a grinding sound, its like a clunking/clicking/wierd rattle type sound. im nt 100% sure that the starter motor is engaging properly to turn the engine over sufficiently.


The spark plug im using is a Br10. ( although ive looked about and different places stay different things, some say br10, some say br9.) Is it br10 as my bike is fully derestricted?

I think the carb is 34mm btw, should the bike be rejetted after this? if so, how do i know it has been. (sorry if this is a daft question)

[stirlinggaz]

Hi,
if it has the standard carb, then its the 28mm., unless someone has upgraded it.
(the 34mm carb was only standard on the older rs)
spark plugs (as recommended by rotax) :
BR8 for restricted version
BR10 for full power version OR
BR9 for full power version if you dont intend red-lining it continously.
i have always found the BR9 to be more suitable, as it wont foul as easily & the bike will usually be easier to start..
definitely test compression, as hard starting can be a sign of low compression & sometimes just new rings will cure this.
(get a good tester on it, test it 2 or 3 times & post results)
the clunking noise you hear will likely be the bendix gear rather than starter motor.
the starter motor does take a bit of punishment due to where its situated & can be re-furbished, though might be easier just to replace.
still tempted to think its just the usual clunky starting issue, caused by a low battery or/+ the bike being sitting around for a while.
AND the carb needing cleaned & set up properly,
(theres a good guide on here by Kickstart about dellorto carbs)
cheers,
GAZ

[skills]

I had the same sort of problem with my RS 125, I do not know alot about bikes but I do know that the problemm was something pretty simple. I'll find out exactly what this problem was and get back to you. Hopefully it may be able to help you too.
____________________
Billy. Loved my aprilia rs 125, also love to find the kids who nicked it. Soon as the insurance pay out i'll be buying another. https://www.apriliars125.co.uk

[SillyMe]

Yeah check the float chamber, had loads of trouble with mine, the floats them selves were filled with petrol so couldn't maintain hight to shut off the needle valve. This alone will make these bike run horrible, Full of gunk too. Give it a good sorting pal and try again.



Well I can speak from experience here as I too was ripped with an Aprilia RS125. I got it really cheap off ebay and realised there would be something wrong, but it still stood me in credit after I fixed it.
It's a very common thing i'm afraid.

When you said the engine sounded really bad after the initial fire up, this indicated to me the top end needs a rebuild.
It's difficult to tell without a proper compression test becasue my barrel was OK(No scratches), I had it rehoned anyway and fitted a 10th of a milli oversized Vertex teflon coated piston kit. Trickly little job.
If you need to go down this route you will need top end gasket kit, you may need jubilee clips for the hoses as a result of not having the correct Aprilia tools to remove the hose clips fitted as standard, and a few cable ties for the wiring loom. You even need a special tool for the reed block, this keep Aprilia mechanics in work, but you won't need to remove this.

When the carb isn't set correctly on these they don't run I'm afraid, I believe they are designed to fail. Horrendous but true. Keeps people in jobs and scampsters in pocket.
These helped all the way, they specialise in Aprilia's
https://www.pjme.co.uk/
https://www.pjme.co.uk/

https://www.swiftcover.com/motorbikeinsurance/faq/
Follow the instruction and fill in the fields, you will be issued with a load of qoutes starting with the cheapest.
Just call the brokers who give you the best qoutes direct from the number given.

Sorry guy's gunna hog this thread with a few pics too.

https://img193.imageshack.us/img193/5821/dsc00075xs.jpg

Make sure the two stroke feed is set up correctly!
https://img135.imageshack.us/img135/1194/dsc00072z.jpg

Rehoned for 10th of a milli oversized piston kit to be installed.
https://img718.imageshack.us/img718/3623/dsc00074ee.jpg

Notice the white cable ties.
https://img412.imageshack.us/img412/1606/dsc00067rz.jpg

And finaly the beast here self running like a dream.
https://img176.imageshack.us/img176/1914/dsc00077by.jpg
____________________
Once made equal to man, woman becomes his superior.
The man who says "I may be wrong, but -" does not believe there can be any such possibility
Owned and rode: Honda 100H, Honda MBX 125, Kawasaki AR 125, Suzuki RG 125 Pepsi, Honda NSR125 RK, Honda NRS 125 race bike, Suzuki GSXR 400 Bandit, Aprilia RS 125 O2, Honda CG125, Kawasaki KMX 125, Aprilia RS 125 O6, Suzuki XT225 and now Honda XR 400. ( A few scooters and other dead beats in between)

[SillyMe]

Just one more thing, if it is a top end job it cost me no more than £150 plus the train fare to Wolverhamton and back.
____________________
Once made equal to man, woman becomes his superior.
The man who says "I may be wrong, but -" does not believe there can be any such possibility
Owned and rode: Honda 100H, Honda MBX 125, Kawasaki AR 125, Suzuki RG 125 Pepsi, Honda NSR125 RK, Honda NRS 125 race bike, Suzuki GSXR 400 Bandit, Aprilia RS 125 O2, Honda CG125, Kawasaki KMX 125, Aprilia RS 125 O6, Suzuki XT225 and now Honda XR 400. ( A few scooters and other dead beats in between)

[121game121]

I have exactly the same issue. My Aprilia RS 125 1999 wont start, bought off ebay for cheap but caus it had MOT done in July 2010 i thought there wont be much work needed to be done.
Bought new battery, fitted a bigger main jet. Tried starting it a few times and it just struggles then dies out.
Now going to buy a new spark NGK B8 ES.
Anyone know how to do a compression test? Newbie to bikes.

[N cee thirty]

hmm,is it sparking ?

is the plug getting wet ?

if you wanna do a compression test get a tester off ebay,or take out the plug and put your thumb over the hole and turn over the engine with the throttle fully open,it should blow your thumb off but not a good test really
____________________
'00 Aprilia RS50 > '92 Honda CG > '99 Yamaha Fazer > '91 Yamaha RXS > '79 Suzuki X5 > 01' Honda Cg > 07' Honda Cg > 82' Kawasaki Z200 > suzuki gsxr 400 gk73a > honda vfr 400 NC30 Mod 2 Passed 09/06/2011

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