Thumper Club Forum

Technical => Bike Problems/Questions => Topic started by: guest1406 on June 20, 2014, 02:28:48 PM

Title: Shakedown ride shook the spark
Post by: guest1406 on June 20, 2014, 02:28:48 PM
Hi there,

After two years of building the project, I finally insured and took it for its first ride!! Exciting, believe me!
Yet it broke down ..

After riding nicely about a mile or so it suddenly backfired and stalled. I pulled over and tried to start it again it but nothing. So a push to a friends house (Including two bloody hills!!) it was.

On inspection I checked the plug and spark, no spark. So I changed the coil for a brand new one, exactly the same -  still no spark. There's power to both terminals on the coil. That's as far as my electrical knowledge spreads.

Any suggestions?

Mackenzie
Title: Re: Shakedown ride shook the spark
Post by: 500 T C on June 20, 2014, 06:20:01 PM
When you say you checked the spark plug, was it wet with fuel? If its an NGK, they do not like getting wet with fuel,I had experience of this happening,was the choke still being used?  Was the engine warmed up and off the choke?                         Suggest  using another new spark plug. Just thought,  I would throw a few clues in. Good luck.
Title: Re: Shakedown ride shook the spark
Post by: Propellor on June 20, 2014, 06:22:29 PM
Power to both terminals on the coil? Shouldn't it be just one terminal? The other being earth?
Title: Re: Shakedown ride shook the spark
Post by: guest1406 on June 25, 2014, 02:28:47 PM
Plug was brand new, and then cleaned before trying for spark. At the moment I'm just trying to get a spark.

Pick up came yday, it was switched over and still no spark, thankfully an original coil was delivered today and I'll try that.

Mackenze
Title: Re: Shakedown ride shook the spark
Post by: 500 T C on June 25, 2014, 04:57:27 PM
 Yeah , in my experience  spark plug was brand new, and cleaning it makes no difference, I assume its an NGK?Just try  another plug, before looking too deep.
Title: Re: Shakedown ride shook the spark
Post by: guest1406 on June 27, 2014, 06:27:14 PM
Plugs were changed over to see if it was the plug as soon as i realized there was no spark.

Coil came, still no spark!!

On intense wire inspection i came across a very warped and melted CDI. So thinking that may be problem another one has been ordered. Serves me right for buying moody Chinese parts!

Mackenzie

Title: Re: Shakedown ride shook the spark
Post by: Moto63 on June 27, 2014, 06:37:20 PM
Oh dear the curse of the chinky Chinese parts strikes again, hopefully you,ll get it sorted soon mate. Keep ya chin up. Regards Michael
Title: Re: Shakedown ride shook the spark
Post by: guest1406 on June 27, 2014, 06:48:42 PM
Yeh my own fault!

Cheers! Hopefully it does work - if so i have the chance to be a rider for an Italian Vogue Magazine shoot!!

I'll let you know how the cdi goes when its here!

Mackenzie
Title: Re: Shakedown ride shook the spark
Post by: Moto63 on June 28, 2014, 11:22:52 AM
Sounds interesting, what is it you,ve built? Must be something nice if vogue want it gracing their pages. Can you post some photos? Always interested in seeing specials.  Regards Michael
Title: Re: Shakedown ride shook the spark
Post by: guest1406 on June 29, 2014, 02:08:38 AM
Started life out as 2003 Suzuki Van Van. With some extensive modification it is now quite different! modifications include:

- GN250 engine, top end rebuild with a 300cc barrell and piston
- Mikuni TMX38 Flat Side Carb, rejetted with K&N Filter
- Extensive frame modifications for engine fitting
- Rear frame loop
- Relocated hidden battery box
- Hidden electrical box
- Relocated ignition switch and headlight switch
- Remote front brake master cylinder
- Custom made hidden simplified wiring loom
- Ball end levers with indicator toggle switches built in
- Mini Koso speedo
- Bates style headlight with yellow vinyl wrap
- Two into one wrapped high exhaust
- Powder coated satin black
- Bare metal 2.4 gallon Harley Sportster tank
- Bare metal narrowed mudguards
- Custom fiberglass seat base and seat upholstery

Follow our blog - c o c k neycustoms.blogspot.co.uk (Although as of recently EVERY picture has been wiped off)

First day of life - www.youtube.com/watch?v=VgN7BywznfM



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Title: Re: Shakedown ride shook the spark
Post by: Moto63 on June 30, 2014, 07:13:48 AM
Sounds and looks interesting , certainly different. (No bad thing in my book) sounds like you,ve put a lot of time, effort and most likely money into it?  How did the vogue shoot come about, do you have links with the publication or did they just spot your blog and pick it up from there? Either way hope it all pans out well for you in the end and I,ll have a look on your blog spot as I,d like to see the bike in it,s finished form.  Keep us posted of developments.  Regards Michael
Title: Re: Shakedown ride shook the spark
Post by: guest1406 on June 30, 2014, 10:01:16 PM
Cheers Michael! A fair bit of money yes! But honestly the way I see is, two years ago at the start of the build I knew nothing about bikes, and now I'm half confident around a bike and its opened so many doorways!!

The vogue shoot came about through a friend (blackskullslondon.co.uk) who's wife knew someone who wanted a few young bikers for a video a shoot. Its something for the young London bike scene and few of us fit the bill!

I'm in process of updating and re-picturing the blog at the moment.

Also new CDI comes tomorrow so I'll update the topic soon!

Mackenzie
Title: Re: Shakedown ride shook the spark
Post by: Moto63 on July 01, 2014, 07:30:39 AM
Young motorcyclists you say, that,d count me out then. DOH.  Still good to see "young" lads (girls?) getting their fingers dirty and then hopefully enjoying the fruits of their labour. Keep up the good work we need more young guns getting into bikes and we need more special one off builds. Regards Michael
Title: Re: Shakedown ride shook the spark
Post by: guest1406 on July 02, 2014, 10:16:46 AM
Haha cheers Michael!

Well yesterday I fitted the new CDI!

She started! A test drive around the block she was fine! Did a quick compression too and got 151 which is surprising

Another test ride .. . Happened again. A backfire, loss of power and no spark. Curse of the CDI

Im beyond CDIs and electrical components, but it was getting really hot when attempting to start and very rarely it would throw a spark out.

Any suggestions? I'll be ringing the wiring guy tomorrow and see what he says

Mackenzie
Title: Re: Shakedown ride shook the spark
Post by: Moto63 on July 02, 2014, 11:59:17 AM
Sorry mate but sparks are defo not something I,m that good with so anything I might suggest might just put you back further still. I,m feeling for ya, soul destroying stuff but keep at it, it WILL be worth it in the end. Keep me posted.  Regards Michael
Title: Re: Shakedown ride shook the spark
Post by: themoudie on July 02, 2014, 07:20:53 PM
Aye Mackenzie,

This link will not provide comfort, but seems typical of the palaver that you and others have with old GN250 ignition.

GN250-ignition-woe (http://www.perthstreetbikes.com/forum/f14/any-advice-appreciated-gn250-problems-155867/)

I can only suggest as others have here and on other sites to other folks with the same problem, clean all the connections, be methodical and expect to be a very long time. In your case the CDI appears to be the problem, but have you identified why it blew in the first place? It would appear that that fault still remained when you connected up the replacement unit and that too has gone 'PHUT'! ???

If it helps, view the wires as water pipes and some maybe leaking in hidden places, where they maybe chafed or subject to regular pushing or pulling. Wires may also be covered in verdigree behind covers or within connectors and are out of sight. Pull each joint, multi-connector apart in a systematic order and clean and protect with ACF50 or replace as you go along. Tedious, yes, but as you previuosly said you wont be paying somebody else to do what you can do and you'll be learning as you go.

Source of wiring supplies. Link: Vehicle_Wiring_Products (http://www.vehicle-wiring-products.co.uk/)

As the Python song goes "Always look on the bright side......!"

Hope this helps.

My regards, Bill.
Title: Re: Shakedown ride shook the spark
Post by: Propellor on July 03, 2014, 05:48:56 AM
Mega frustrating, after putting so much work in. Hopefully your sparky geeza can sort it.

Are you using a cdi unit specifically designed for this bike?

From what I can gather there are two basic types. Ac-cdi, which don't require a battery as they generate a pulse from a coil on the "flywheel". And battery cdi, which use the dc supply from the battery and convert it via a mini inverter, built in. Apparently this type need a battery in good health. I presume you have this type as you have said you've got voltage at the coil?

Another possibility is that you're using a 6 volt version on a 12 volt system? Or vice versa. Dunno. Just (feebly) throwing ideas up.

Good luck.


Edit: maybe you're using a cdi unit for the "bike" (van van) whereas you should use one (and wire a circuit accordingly) for the "engine" ? Is that a possibility? I don't know enough about either bike to be sure.
Title: Re: Shakedown ride shook the spark
Post by: guest1406 on July 09, 2014, 02:16:15 PM
Hi All,

Sorry for the delay in news, been a few busy days.

In the end we knew it was coil. The coil used was a mini universal one which just wasn't compatible with the circuit, additionally i don't think the moody Chinese copy of a cdi helped either .. .

So I ordered a brand new GN250 coil first class and it arrived at 1pm on Saturday. Bearing in mind I had work from 2pm to 10pm and we had to be in Dunsfold aerodrome (50 miles away) at 10am sunday morning. It was a mad rush and i ended up finishing the bike up at 1am sunday morning. It turned out it just needed the original coil.

I was very nervous for the bikes 100+ mile drive on its first day, but it made it with very minor issues that can be easily dealt with. The shoot was good fun, a good experience and the model ended up posing on my bike for a while!! i'll definitely get some pics when the mags out in September or so.

So now its just fine tune and adjust pretty much everything but im happy with the outcome!

Mackenzie
Title: Re: Shakedown ride shook the spark
Post by: Moto63 on July 11, 2014, 07:17:34 AM
Nice one, knew it,d be worth it in the end for you. We'll done. Looking forward to seeing the pics, the curvy lines, the sleek poses. And some of your bike too.   Regards Michael