wanted - moto giro bike

Dellortoman

Hero member
on the advice of the VAPE tech folks I ordered some peculiar NGK plugs that have three ground tabs circled around the center electrode, I test fitted on my spare Gilera head, they were a tad longish, so used three spacer washers to get installed length perfect, fitted to the bike and fired up, oddly enough engine sounds noticeably different to me in a good way.

Spark plugs with multi ground electrodes have been around for ages. I've seen them with electrodes numbering from zero to four. Of course, the manufacturers of each type of plug claim that theirs is best. But you'd think that if any particular configuration offered a significant advantage over the others, then everyone would be using them.

Er, hang on ... everyone IS using a particular configuration - the single electrode type.

I've read reports that say the extra metal in the multi-electrode type tends to conduct heat away from the initial flame as it first begins to form (flame kernel) resulting in a slower burn rate. So you may get the same result by using a conventional plug and retarding the ignition a tad. It would be helpful if Vape actually gave you access to their pre-programmed ignition curves (yes, I'm still pissed off about the conversation I had with Vape on that subject).

Also, additional ground electrodes surrounding the centre positive electrode tend to block the passage of the flame front, further slowing down the flame propagation and leading to a less reliable and less stable flame.

The impression I get from a little bit of research is that the fewer ground electrodes the better, to the extent that no ground electrode at all is ideal for the best flame propagation. Surface gap plugs (no ground electrode) were favoured by Kawasaki on their 2-stroke triples for a time. However, not having a ground electrode offers no opportunity to adjust the spark gap. The spark just jumps from the centre electrode to any random spot on the outer grounded part of the plug. I guess that's why single ground electrode plugs that allow an adjustable gap have become the default plug type.

This technical paper contains a lot of jargon and test result charts, but it seems to support the points I stated above. https://www.sciencedirect.com/science/article/pii/S2090447912000883
 
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Paul LeClair

Administrator
Staff member
Hi Cam

I read your info with interest re the spark plugs. The VAPE technical folk highly recomended them, not sure why. As you found out, they are keeping closely guarded secrets about their ignition for no apparent reason....

the only way I can see to change timing with the VAPE system to advance or retard by small amounts is to pull the rotor and relocate it in relation to TDC. I currently have so much LocTite 680 on the crank end and rotor that puling the rotor may not be all that easy even with the dedicated puller... :rolleyes:

For now, once my Sudco carb parts order arrives I am going to concentrate on dialing in the VM18 Mikuni on a dyno with an exhaust gas analyzer

I have arranged to go look at a non running project condition 1968 Ducati 250 Scrambler next weekend, needs a complete motor re-build apparently. I am now learning aboutDucati narrow case vs wide case engines and frames, different heads, etc.. Not interested in a "desmo", would be happy with a conventional head, less of a learning curve if I venture down the old Ducati single path.....
 

bazzee

Hero member
Location
Sydney
I have arranged to go look at a non running project condition 1968 Ducati 250 Scrambler next weekend, needs a complete motor re-build apparently. I am now learning aboutDucati narrow case vs wide case engines and frames, different heads, etc.. Not interested in a "desmo", would be happy with a conventional head, less of a learning curve if I venture down the old Ducati single path.....
Have you considered a two-stroke? No cams at all...
Cheers,
bazzee
 

AJ

Senior member
Hi Cam

I read your info with interest re the spark plugs. The VAPE technical folk highly recomended them, not sure why. As you found out, they are keeping closely guarded secrets about their ignition for no apparent reason....

the only way I can see to change timing with the VAPE system to advance or retard by small amounts is to pull the rotor and relocate it in relation to TDC. I currently have so much LocTite 680 on the crank end and rotor that puling the rotor may not be all that easy even with the dedicated puller... :rolleyes:

For now, once my Sudco carb parts order arrives I am going to concentrate on dialing in the VM18 Mikuni on a dyno with an exhaust gas analyzer

I have arranged to go look at a non running project condition 1968 Ducati 250 Scrambler next weekend, needs a complete motor re-build apparently. I am now learning aboutDucati narrow case vs wide case engines and frames, different heads, etc.. Not interested in a "desmo", would be happy with a conventional head, less of a learning curve if I venture down the old Ducati single path.....
Applying heat will help you getting the rotor fixed with Loctite off. 680 is only good up to 150 degrees C
 

Dellortoman

Hero member
Be very careful applying heat to the VAPE rotor to un-stick the Loctite. 150°C can damage the alternator system.

The rotor comprises permanent magnets for the alternator. Excessive temperature can turn them into permanent non-magnets. The critical temperature varies a bit with the type of magnet, but I'd recommend that you don't let the magnets get above about 80°C. The magnets are secured around the inside of the cylindrical wall of the rotor, so be careful to apply heat to the hub area only.

Use a small butane torch and just play it around the centre of the rotor and exposed crankshaft end (you'll have the nut off the shaft at this stage). If you're quick, you may be able to get the thing off without much heat finding its way to the magnets. If the process is taking a while, try wrapping some wet rags around the outside of the rotor to keep it cool.

Also, there's a bunch of holes around the rotor hub. You may want to consider covering those holes with some kind of heat shield (maybe allow your wet rags to wrap over them). You don't want heat diverted from your gas torch flame getting in through those holes to heat up the inside of the rotor. Otherwise, it'll become like a little oven inside. Apart from overheating the magnets (both alternator and ignition pickup), it could also burn the insulation lacquer on the stator windings and potentially melt the plastic insulation on the ignition and alternator wires in there.

Actually, you're fortunate that there's a recess for the nut in the centre of the rotor. The gas flame will tend to be deflected straight back towards the torch rather than splay out across the face of the rotor, so you should be able to concentrate the heat into that area without too much risk to the rest of the system.

vape rotor.JPG
 

GregT

Hero member
Location
Hororata NZ
I have arranged to go look at a non running project condition 1968 Ducati 250 Scrambler next weekend, needs a complete motor re-build apparently. I am now learning aboutDucati narrow case vs wide case engines and frames, different heads, etc.. Not interested in a "desmo", would be happy with a conventional head, less of a learning curve if I venture down the old Ducati single path.....

Been there with 250 springer Ducatis. Only really a few key areas. The oil pump is one. I always replace the bronze bushes the shafts run on as excessive clearance sees oil bleed out of the pump body. The big end. Must be pulled down and checked as a minimum. Valve springs. last one I did there were only two options available - slightly too strong and slightly too soft. Effectively race or road. Get good at shimming bevels too. Time spent setting up the bottom end always pays off on these.
Someone in the US does replacement wiring harnesses for them too. Correctly colour coded. Which was a relief after one that had been wired using purple wire for everything....
 

Vince

Hero member
I thought the ignition came off the taper with a bang and that's what caused the engine stoppage. Plus didn't I get grief about using Loctite on a taper? So what came away with a bang and got eaten up? I am as usual confused. Lots a talk about an allowance in case shimming on Ducatis, some art instead of Science required.
 

Paul LeClair

Administrator
Staff member
Hi Vince

yes, in the Moto Giro the bloody rotor came spinning off the end of the tapered crankshaft and banged around inside the engine cover. As the rotor also contains the ignition timing trigger the engine quit.

Since then I have slathered the rotor and crankshaft end with LocTite 680, using the separate activator spray to help it set up.

Then it was suggested that I change the ignition timing advance or retard a bit re spark plugs, carb settings etc, but at this point after my "repair" the only way to do that I can see with the Vape is to move the rotor on the crankshaft end however many degrees I want to advance and retard. Tough to do now that I have basically glued the rotor in place with the Loctite 680 retaining compound since returning from the failure at teh Moto Giro.

Going to dyno the bike using an exhaust ratio analyzer once my Sudco sourced carb parts arrive, see how that goes, and see if the rotor comes flying off on the dyno.......
 

bazzee

Hero member
Location
Sydney
Hi Vince

yes, in the Moto Giro the bloody rotor came spinning off the end of the tapered crankshaft and banged around inside the engine cover. As the rotor also contains the ignition timing trigger the engine quit.

Since then I have slathered the rotor and crankshaft end with LocTite 680, using the separate activator spray to help it set up.

Then it was suggested that I change the ignition timing advance or retard a bit re spark plugs, carb settings etc, but at this point after my "repair" the only way to do that I can see with the Vape is to move the rotor on the crankshaft end however many degrees I want to advance and retard. Tough to do now that I have basically glued the rotor in place with the Loctite 680 retaining compound since returning from the failure at teh Moto Giro.

Going to dyno the bike using an exhaust ratio analyzer once my Sudco sourced carb parts arrive, see how that goes, and see if the rotor comes flying off on the dyno.......
If I understand things correctly it seems like the Vape system has some fundamental issues. It would be nice if the rotor was fixed in position with a key, fairly standard practice. Also some (documented) switch or software adjustment would be useful.

Cheers,
bazzee
 

Paul LeClair

Administrator
Staff member
If I understand things correctly it seems like the Vape system has some fundamental issues. It would be nice if the rotor was fixed in position with a key, fairly standard practice. Also some (documented) switch or software adjustment would be useful.

Cheers,
bazzee
there are 4 switches on the ignition control box but VAPE declines to share what each does or changes. Cam started figuring them out, but no idea why it is supposedly such a big secret. If I had known that going in I am not sure if I would have proceeded to buy the Vape, not that there are a lot of alternatives..... I was mostly after the 12 volt conversion and good charging to run bright lights. I am aawre of a couple of people that still runt eh Vape for the 12 volts but are using points and mechanical advance, simple to do.

myself, i am eyeing the end of the cam that typically drives the poitns as a potential drive for a small supercharger..... :eek: :cool:(y)
 

Dellortoman

Hero member
I don't understand VAPE's business model if they think that keeping their range of advance curves secret is a good idea. From the point of view of a potential purchaser of a VAPE ignition, it pretty much makes their product a non-viable option. I think it's an arrogant attitude for them to withhold the advance curve information, thinking they know better than their customers what advance curves they should use. I actually told them that, but then they stopped communicating with me. For all they know, they may have a customer who's crazy enough to fit a supercharger, which would need something quite different than their default ignition curve.

Paul, if you're ever tempted to ditch the VAPE ignition, it would be a simple modification. Most of your wiring would remain intact. You could keep all the 12V VAPE alternator and RR for running your lights and accessories. All you'd need to swap out is the actual ignition box. If it were my bike, I'd choose an Ignitech unit. It could use the existing VAPE pickups and coil and would give you fully programmable ignition.
 

GregT

Hero member
Location
Hororata NZ
Put f....ing points on it for Gods sake.
A lesson in how to make a simple machine not run by complicating it.

Paul
Tend to agree. All it needs is about 15 degrees of retard at cranking speed with the advance all in by around 2000rpm.
Wait till he gets onto the Ducati. 6V ignition - and the points cam on some models don't give enough dwell.
 

Paul LeClair

Administrator
Staff member
Ah ... the good old days of points. No time for vehicle maintenance today though, as I have to go out and patch up the wattle and daub walls of my hut with some nice fresh cow dung. Then I can relax and put the old black billy on the fire for a nice cup of gum-leaf tea.
had me laughing out loud, my wife just called up from downstairs asking what I was chuckling about........
 

Paul LeClair

Administrator
Staff member
Put f....ing points on it for Gods sake.
A lesson in how to make a simple machine not run by complicating it.

Paul
I was thinking in addition to points could go back to acetylene lighting on the bike as well to further simplify things, and maybe hire someone to walk in front of the motocrycle to warn the horses and pedestrians a motor vehicle is coming.
 

Vince

Hero member
Convert it to electric, really useful in Canada and Oz as it's all tiny trips. The hardest to start and the least reliable bike I ever owned was an XT 500 Yamaha with Points ignition, if it was slightly out of tune you could kick it for days. Guess why my right ACL is in 2 pieces after years of that abuse. The SR 500 road version had an EI, I was so envious of them.
 

Paul Marx

Hero member
Location
France
I was thinking in addition to points could go back to acetylene lighting on the bike as well to further simplify things, and maybe hire someone to walk in front of the motocrycle to warn the horses and pedestrians a motor vehicle is coming.
How many hours a year is your non working electronic ignition going to save you during the 10s of thousands of miles you're going to be doing on that Gilera? Get serious, get a working bike.
That bike was used to transport Italian workers to the fields and factories. It needed to be reliable. If points was good enough for them, and for the bike, they would be more than sufficient for your needs.

Ducati singles don't allow any approximation.

Paul
 

Paul Marx

Hero member
Location
France
Convert it to electric, really useful in Canada and Oz as it's all tiny trips. The hardest to start and the least reliable bike I ever owned was an XT 500 Yamaha with Points ignition, if it was slightly out of tune you could kick it for days. Guess why my right ACL is in 2 pieces after years of that abuse. The SR 500 road version had an EI, I was so envious of them.
Just done 2500km along with 2 bikes with a reputation for hard starting.
A 500 XT and a 350 MAC Velocette. Both started first kick, hot or cold.
Very user dependent though.

Paul
 
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