This is another no-spark problem. I've done a fair bit of searching and found various references, but I'm still missing information that I'm hoping others can provide.

Background - secondhand 07 GG TXT Pro 250. Been going OK for the past few months since I've had it, starts pretty easily. About a month ago I fitted lights (GG original headlight, LED tail/brake. Fitted my own wiring rather than try to sort through the various existing connectors) ready to get Recreational Registration on it, all seemed OK. Yesterday I fitted an additional LED number plate light. Tested OK in the garage.

Yesterday I went for a ride (more of a trail than trials ride). Dropped the bike (low speed, very minor) and found the carb overflows loosing lots of fuel after standing it up. Hard to start. Rode a bit further and found it tended to die/miss a bit when popping the throttle for logs. Stoped the bike to help my son and couldn't get it to start. When I checked the fuel tank I found the breather had locked closed and lots of pressure in the tank. Topped up tank to be sure. Bike would fire a few times then die. Eventually gave up and walked/towed the bike back to the long descent. Once rolling downhill tried roll starting. At first it would fire once, then it gave up totally. 1/2 km of roll start attempts at good speed downhill but nothing doing. Trailered it home. Checked it at home, no spark.

So far I've tried:

• New plug
• disconnect kill switch
• disconnect all lights
• check HT lead resistance (7.3 Kohm)
• check trigger coil resistance (259 ohms)
• check trigger voltage spinning engine with drill (1.5 Vac - this seems low?)
• check yellow (main windings) stator wire to ground (1.2 ohms)
• check voltage from yellow wire when spinning modest RPM (500?) (15V)
• removed regulator from circuit and connected yellow from stator to yellow to CDI (these are direct connected internally in the regulator)
• removed the potting from the back of the regulator to check the diodes that are reported to fail, there was some slight discolouration on the potting in that area (both check OK).

I have an ignition that matches the 2003 Ducati Digital diagram.

I've found various posts that give resistance and voltage figures for the ignition with two sets of stator windings, but not for this version.

So now I'm a bit stuck. I don't know how to isolate the problem further. I'm suspecting one of the following:

1. Trigger coil faulty - the references to the early version ignition suggest the resistance should be higher than I'm reading.Jim Snell mentions these are the most common failure in these systems.
2. CDI/coil faulty - others indicate this is the most common failure.
3. Regulator faulty - currently trying to work out how best to test this. Doesn't seem likely given that the bike wont go even with the regulator totally bypassed.

Trouble is I really don't know how to test these to isolate which is giving the trouble.

Or I'm missing something and it's something else :-)

In the interest of helping others, here are other links I've found that help shed some light on this problem.

Regulator diode repair - I believe the diodes are p600 power diodes, but someone else might verify that.

Resistance readings (older style ignition)

Jim Snell on revisions not actually useful for diagnostics, but sheds some light on what's out there.

Pickup coil meter readings and replacement

The Hell Team resistance chart

Edited December 18, 20178 yr by bikerpet
Added links

Know it doesn't help with your Ducati system but I threw mine away and replaced with the Kokusan system and never had another problem. I note the tank breather was blocked, have you tried starting with tank cap off the bike? Wouldn't be the first dodgy breather I have heard of!

There were many problems with the Ducati systems on the GG trials bikes, and like petert above, we replaced quite a number with Kokusan and never looked back. Most of the problems I have seen were with the regulator, the aluminium cased unit, which if you look at the green potting underneath, you may find a brown discoloured over heated area which invariably is a sign of a component that has cooked. The regulator would need replacing. There were two types, identifiable by having a black or a blue connector. I think one was for the 300, I don't know which colour though. Are you able to borrow another regulator to try out? If you are in the UK, then GG UK should be able to help with this part. Good luck.

Bye, Peter B.

Following out of interest as I have the same bike.... starts ok just now.  Ordered a new plug recently as it decided to take a bout 10 kicks when I stopped last time I was out just before I got back home, was going OK up to then but I know they can be problematic.

I'm sorry that I can't contribute a solution to the problem at hand, but can anyone say which years(s) and which model(s) of GG had Ducati ignitions and which had Kokusan?

And I too had an issue with a faulty tank breather valve; the valve failed and a vacuum would develop in the tank and starve the engine of fuel. And in debugging the problem I'd check the fuel level by removing the cap and unknowingly temporarily "correct" the problem. Doh!

Edited December 18, 20178 yr by d2w

Thanks for the replies everyone.

I took a punt on the advice of The Hell Team and bought a new coil/ignition unit. Problem fixed. My old unit was way off the specs given in the Hell Team resistance chart - mostly way high (double or triple) so I figured this was the likely culprit.

Interesting to see that it seems split between people who report the regulator being the common problem and others saying the coil/ignition unit gives trouble. Sounds like both have their flaws!

I'm now gradually digging all the green potting out of the old ignition unit to see if I can find the faulty component - at the price of these things I can invest a few hours in research! If anyone has already investigated this I'd love to hear from you. If I eventually clean it up and find a faulty component I'll report back. It's not particularly hard digging it out - cut apart the black case then with a plastic chisel quietly dig away. Not sure my electronics skills will be up to isolating the fault if it's not obvious though.

 

On 12/18/2017 at 6:27 AM, d2w said:

can anyone say which years(s) and which model(s) of GG had Ducati ignitions and which had Kokusan?

 

When I was fighting with my Ducati system I was in contact with Jim to help find a solution and he sent me all of the following information which was very helpful and interesting. This is word for word what Jim sent me. Hope this helps!

 

As I remember it, in my 25 years, GG had In the older engine Trials and Pampera bikes that ended in 2002

Motoplat

Ducati

Kokusan

Leonelli

 

In the Pro models

2002 Kokusan (one year only system like the used one that I just sold. VERY good system, almost no problems ever.)

2003-04 gen. 2 Kokusan, also very good

2005 Ducati first gen with programmable CDI, (we had to buy programming software and interface hardware for this and it only worked in Windows 95 which was already obsolete by that time.. I have a Windows 95 vintage PC still operable solely for programming these CDI units. grrrrrr. Perfect example of how much the old GG lacked simple common sense. - some stator failures that year, especially on the 300cc bikes for some reason.)

2006 Ducati second gen., and back to Kokusan in 250/280 bikes

2007-08-09 Kokusan but different again

2010-11-12 they were using whatever they could find at the time but mostly Kokusan but sometimes Ducati

2013 Hidria early versions but another version of Kokusan on the Raga Replica

2014 Hidria early version and the new "D/C" version on the Raga Replica 30th anniversary edition

2015 Hidria hodge-podge as they spiraled into the final closing.

Any of these faults manifest themselves as difficulty hot starting? Or could I put that down to being tired and wedged in some rocks?

Stator Removal

How do you get the stator and pick up coil off?

Its been a long day.... but don’t have a small enough spanner as get the flats on that LHS boss on the coil. Can you lock it up with a couple of nuts and screw it out?

13 hours ago, miner said:

Stator Removal

How do you get the stator and pick up coil off?

Its been a long day.... but don’t have a small enough spanner as get the flats on that LHS boss on the coil. Can you lock it up with a couple of nuts and screw it out?

If I remember correctly it is some odd size like a 7mm. Whatever size it is, I don't have a wrench for it.

As sad as this sounds I usually use Vise-Grip (locking pliers) or regular pliers to get that out.  Might be able to do the jam nut technique.

Cheers for that... stopped short of locking the mole grips on it and couldn't get enough purchase on it locking the nuts to crack it off.... was able to clean up everything in there without taking it off but it definitely would have been easier with it out of the way.

Put the cover back without the gasket for now as it was falling to pieces.  Stumbled on some chats last night about the venting of the casing which I found interesting... saw some stories about people sealing the casing but running a breather up behind the tank.  Others leaving a gap to allow air/water to escape which I couldn't quite get my head round till I saw the amount of water marks coming down from the pulsar coil gaiter.... looks like these are prone to letting water in?  Could this be why there's a chunk out the gasket at 5'o-clock?  Is it worth sealing this up with silicone?

Other point I read was about pressure build-up due to air windage inside the compartment.... flywheel is massive compared to a 2T Kokusan MX/EXC flywheel and proportionally a lot more (almost all) of the space taken up so I guess there could be something in this (can be fatal for turbomachinery... not sure about a wee 2T engine), MX/EXC there's a lot of air gap for the weight to spin in so no issues I guess.  Is this a thing?  Or just something I stumbled across to be ignored?

 

On 24/12/2017 at 3:17 AM, caleb93 said:

 

 

When I was fighting with my Ducati system I was in contact with Jim to help find a solution and he sent me all of the following information which was very helpful and interesting. This is word for word what Jim sent me. Hope this helps!

 

As I remember it, in my 25 years, GG had In the older engine Trials and Pampera bikes that ended in 2002

Motoplat

Ducati

Kokusan

Leonelli

 

In the Pro models

2002 Kokusan (one year only system like the used one that I just sold. VERY good system, almost no problems ever.)

2003-04 gen. 2 Kokusan, also very good

2005 Ducati first gen with programmable CDI, (we had to buy programming software and interface hardware for this and it only worked in Windows 95 which was already obsolete by that time.. I have a Windows 95 vintage PC still operable solely for programming these CDI units. grrrrrr. Perfect example of how much the old GG lacked simple common sense. - some stator failures that year, especially on the 300cc bikes for some reason.)

2006 Ducati second gen., and back to Kokusan in 250/280 bikes

2007-08-09 Kokusan but different again

2010-11-12 they were using whatever they could find at the time but mostly Kokusan but sometimes Ducati

2013 Hidria early versions but another version of Kokusan on the Raga Replica

2014 Hidria early version and the new "D/C" version on the Raga Replica 30th anniversary edition

2015 Hidria hodge-podge as they spiraled into the final closing.

 

On 18/12/2017 at 7:27 PM, peterb said:

There were many problems with the Ducati systems on the GG trials bikes, and like petert above, we replaced quite a number with Kokusan and never looked back. Most of the problems I have seen were with the regulator, the aluminium cased unit, which if you look at the green potting underneath, you may find a brown discoloured over heated area which invariably is a sign of a component that has cooked. The regulator would need replacing. There were two types, identifiable by having a black or a blue connector. I think one was for the 300, I don't know which colour though. Are you able to borrow another regulator to try out? If you are in the UK, then GG UK should be able to help with this part. Good luck.

Bye, Peter B.

 

I have a GG 2004 TXT 280 pro I need a new ignition system for can you tell me where I can get a kokusan ignition system for it ?

thanks 

What is the ignition system you have on there at present and what is causing the problem? Try The Hell Team in Sydney for a Kokusan system. Bye, Peter B.