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Derbi GPR50 starting problems

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Sallyt
L Plate Warrior



Joined: 18 Aug 2008
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PostPosted: 18:43 - 18 Aug 2008    Post subject: Derbi GPR50 starting problems Reply with quote

Hi, new to the site so hoping someone will be able to help.

Bought a Derbi GPR50 nude (2005) for my son in May and have had nothing but major problems with it since.

Bike was fine at first then suddenly wouldn't fire, Ended up changing carb completley and seemed to be ok for a while. Then starter motor went, spring on armature was buggered. While trying to find replacement starter bike would bump fine, two steps and it would catch.

Got second hand starter motor, fitted it and no joy. Down to local garage who said starter motor was shorting out battery so got another starter motor (second hand again), worked fine for 2 days and then spring on this one went.

Now the bike won't even bump start, just locks up. When you hit the starter switch there's just a clicking noise from starter relay (i think!!). Spark plug has got a good spark but only know that as put it on another bike to check, unsure if sparking on GPR. Got compression and fuel. Can't understand why it wont even bump???? Any help greatly appreciated. Thanks frustated mum!!!!
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tutton
World Chat Champion



Joined: 04 Jan 2008
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PostPosted: 21:30 - 18 Aug 2008    Post subject: Reply with quote

The clicking relay means you battery is dead flat...
Should still bump tho..
i think some bikes dont bump very well with flat batterys but sumone will probably disagree.
____________________
Past: '05 Peugeot XPS '99 Aprillia RS125 '94 FZR600R
Current: '02 ZX636 A1P '51 CCM R30
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Sallyt
L Plate Warrior



Joined: 18 Aug 2008
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PostPosted: 22:29 - 18 Aug 2008    Post subject: Reply with quote

Battery was put on charge overnight so don't think it could be that unless the battery is useless aswell!!! Will try another though just in case.
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saikouslx
Renault 5 Driver



Joined: 06 Apr 2008
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PostPosted: 22:44 - 18 Aug 2008    Post subject: Reply with quote

check the reed valve gaskets. If it looks abit ragged just use some instant gasket, then that shud do the trick. Thjats what was worng with my GPR, altho that was a 1999 one. But doesnt change principle!
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ballbag
Two Stroke Sniffer



Joined: 12 Apr 2008
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PostPosted: 13:06 - 19 Aug 2008    Post subject: Reply with quote

you can check if the GPR is sparking by removing the sparkplug, connecting the HT lead to the plug and placing a bit of the plug on the cylinder head (so that its metal on metal). Push the starter button and you should see the spark plug sparking... if not take it to a mechanic..

remember to hold the spark plug by the HT lead or you might get a nasty shock .. I know this.. Rolling Eyes

Derbi's are normally pretty reliable. Have you checked all the fuses?
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samj6
Renault 5 Driver



Joined: 07 Nov 2007
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PostPosted: 20:48 - 19 Aug 2008    Post subject: Reply with quote

my mate had exactly the same problems but with the 125 faired gpr i can't remember exactly but i think it cost him bout 300 to get it sorted and it's still dodgy every so often!! Think it was the ignition coil and something else Confused lol sorry not much help really
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prawny1
World Chat Champion



Joined: 28 Jun 2005
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PostPosted: 00:04 - 20 Aug 2008    Post subject: Reply with quote

If the soleniod is just clicking and it wont turn over with a bump id be looking to see if something from the starter has jammed up against the flywheel stoping the engine from turning, you said it has had starter troubles in the past so check there.
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Sallyt
L Plate Warrior



Joined: 18 Aug 2008
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PostPosted: 21:12 - 20 Aug 2008    Post subject: Reply with quote

Hi all, thanks for all your replies, only just checked my e-mails!!

Ok so first of all, got new battery and nada, nothing, zilch!!

I have checked reed valves a while back but as i've had problems with the carb before i'm loathe to touch it again! Might have to be a last resort.

No spark from plug when using starter switch. Remember i'm just getting a clicking noise when depressing starter switch.I have checked the main fuse located right by the battery and that's fine, any others to check???

Flywheel moving freely.

Just been out to garage and it stunk of petrol, noticed fuel leaking from carb, so float probably stuck. Took out spark plug and turned flywheel and loads of fuel came out of spark plug hole. So that's probably why we can't bump it with that amount of petrol in it. Took tank off and petrol is pouring out of one pipe of the vacuum pump on tank.

Thats the latest guys. will leave it overnight to hopefuly dry out and try bumping again tomorrow. Any more ideas/comments all gratefully recieved. Thanks everyone.
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prawny1
World Chat Champion



Joined: 28 Jun 2005
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PostPosted: 00:42 - 21 Aug 2008    Post subject: Reply with quote

If its definatly the vacuum pipe that is leaking then it will have an internal fuel tap leak (just filling up the engine with fuel via the connection on the manifold,

If the main fuel pipe was leaking fuel (shouldn't with good vacuum fuel tap) the needle valve should have stopped the bike flooding so if the main fuel line is your culprit the needle valve could be stuck/worn or have a badly adjusted float hieght As well as an internal fuel tap leak.
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jake_Gpr50
L Plate Warrior



Joined: 13 Feb 2009
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PostPosted: 17:38 - 13 Feb 2009    Post subject: Re: Derbi GPR50 starting problems Reply with quote

hi im new to this website, i have a Derbi Gpr 50 2000model.

i have a problem with the bike starting, i took off the front mud guard to try and fix a couple of the brackets and i had to ride it around to and from collage and water kept on splashing up at all the eletrics and the bike kept cutting out. i got the bike home and took the coil off and dryed it with a hair dryer and i dryed all the eletrics and i have a spark and there is petrol getting to the spark plug "which i renewed aswell" but it just still doesnt want to start can any one please help me regards jake

email me on jakeglasgow@hotmail.co.uk Smile
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Old Thread Alert!

There is a gap of 330 days between these two posts...

DERBI DOCTOR 99
L Plate Warrior



Joined: 10 Jan 2010
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PostPosted: 12:17 - 10 Jan 2010    Post subject: Re: Derbi GPR50 starting problems Reply with quote

hello there..
i own a derbi gpr 50 race replica and i had serious problems with it starting and i had to bump it in every dry place possible and was starting to get on my nerves.
my solution is quite simple really... problems that could occur are as the followings below...

1. clean the exhaust baffle (rod with holes in the muffler) as carbon sticks to it and could suffercate breathing area so dip in a flammable substance such as parrafyn, burn the baffle and rub it with a wire brush or ..... buy a road legal race can, thats what i did.

2. check carburettion as it could be over-flooding your engine or your mixture is too rich- check float height

3. use better oil than what your already using (castrol is my recommendation)

4. lubricate the bike in every place apart from brake disks and calipersas you are masking a sheet of oil over them and obviously the brakes will not be able to grip disks

5. starter motor could have seized and could need anew.


6. if you hae worn out the battery the best thing is to buy a new one.

7. CHECK YOUR TICK-OVER SCREW! i had my derbi and the idiots put my revs ticking over at 1000rpm .. you want it ticking at more than 1000 and less than 2000.

8. weak spark, pick up coils too far from rotor
no spark, sooty spark plug or faulty rotor

9. if none of this has helped your bike is in need of a serious service, send in to the nearest dealer and if he is good enough he should charge you only 50 for full service check.

derbi has a regular occurance with starting problems and it all relies down to 2-stroke engines... their rubbish... good top end but 0% in reliability, you'll be lucky for a derbi to last you 10 months before it needs a new engine. dont hurt the bike and rev its butt off , keep it running nice and easily, 2/3s of throttle for first 100miles.
last and final thing, if you have had the bike de-restricted thats when the problems come in, shorten engine life and it just simply wont start unless you do something about it DO NOT DE-RESTRICT BEFORE 600 MILES!!.. my dad and the people at his work were draining my head with all of this information and beleive me, it worked.
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swiftb
World Chat Champion



Joined: 20 Oct 2008
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PostPosted: 20:12 - 10 Jan 2010    Post subject: Reply with quote

I think he may have fixed it or given up by now Laughing considering it was posted nearly a year ago
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ms51ves3
Super Spammer



Joined: 08 Jun 2007
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PostPosted: 20:18 - 10 Jan 2010    Post subject: Re: Derbi GPR50 starting problems Reply with quote

DERBI DOCTOR 99 wrote:
derbi has a regular occurance with starting problems and it all relies down to 2-stroke engines... their rubbish... good top end but 0% in reliability, you'll be lucky for a derbi to last you 10 months before it needs a new engine. dont hurt the bike and rev its butt off , keep it running nice and easily, 2/3s of throttle for first 100miles.
last and final thing, if you have had the bike de-restricted thats when the problems come in, shorten engine life and it just simply wont start unless you do something about it DO NOT DE-RESTRICT BEFORE 600 MILES!!.. my dad and the people at his work were draining my head with all of this information and beleive me, it worked.


Crap.
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swiftb
World Chat Champion



Joined: 20 Oct 2008
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PostPosted: 20:52 - 10 Jan 2010    Post subject: Reply with quote

Tis indeed crap.

Actually had a gpr50 (and still in the family) for 12 years and the only problem its ever had was a corroded plug cap.
Replaced lead, plug and cap for less than 10 and still running strong today.
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Dalemcgarry
L Plate Warrior



Joined: 12 Jan 2010
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PostPosted: 19:45 - 12 Jan 2010    Post subject: Derbi gpr Reply with quote

I have got problems with my gpr there is no fuel getting to the plug I have put on new fuel lines and a new vac but it's not the same size it's just a bit bigger. There is some fuel in the fuel line but not all the way maybe 1/4 and when you hit the starter a little bit of fuel comes from the tank and some bubbles small bubbles come out from the carb where the fuel line goes on can someone please help me get it started?
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Old Thread Alert!

The last post was made 9 years, 160 days ago. Instead of replying here, would creating a new thread be more useful?
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