ducatipaso.org

Maybe most important:
It`s a 90`s Ducati.

Something is out of whack...false neutrals are not the norm even for Ducati

paso750 wrote:Assuming that the carbs are synchronized

I can't see why they shouldn't be. It had the full-wax treatment before I rode it, that was back in May if this year. It has started well and run perfectly in the interim. Up until the starter shat itself, it was running superbly! I didn't touch anything other than the starter and the alternator case/water pump.

paso750 wrote:and the spark plugs are ok

Should be! They're less than 2000 kilometres old, with a girly-man riding it.

paso750 wrote:for better starting there are basically 4 cures. Fresh fuel...

98 Octane, 20 litres. The good stuff. Less than 2 weeks old.

paso750 wrote:the wiring mod for the coils

Where would I locate this? Is it difficult?

paso750 wrote:stronger coils (like Dynas) and a proper (thicker & better) wiring for the starter and grounds.

Are the coils an easy-replace? The wiring to the starter appears pretty heavy duty as it is, and the bike cranks like fury with the new starter. (That's good, right?)

paso750 wrote:The first three will improve the starting the last the cranking. (the first two are a must) If all this won`t help you should definitely check the clearance pick-ups to flywheel.

G.

What is this clearance pick-up to the flywheel you speak of?

I have wiggled and poked just about every electrical connection I can get to. I tried flipping the run/kill switch while cranking. I have heard a few pops from the engine, which would seem to indicate some sparking action.

Knew I shoulda boughta Gixer...

higgy wrote:Something is out of whack...false neutrals are not the norm even for Ducati

Thanks Higgy. I suspect so. It seems obvious no company could release a bike with this many neutrals in it. I will solve the no-starting problem first, and then worry about this issue.

Where would I locate this? Is it difficult?

It`s easy, just remove the orange wire that goes to both coils, isolate one end and connect the second to a relay. Then run a wire (1,5mm² will be absolutely sufficiant) with a fuse in it from the battery to the relay. Then the relay needs a ground connection and an Y-wire that runs to the coils. That`s it. The relay will be activated by the starter button and the coils will get the full battery voltage w/o any voltage loss. Looks like this

Are the coils an easy-replace?

It`s possible that you`ll need to make a new mounting bracket, not sure about that (would need to check). The wires at Dyna coils are connected with ring connectors, not spade connectors like the original ones. With aftermarket coils you`ll also need new spark plug wires. All in all I`d say it`s easy.

The wiring to the starter appears pretty heavy duty as it is, and the bike cranks like fury with the new starter. (That's good, right?)

Yes, it is. There was a long discussion on the P750 forum about this. Larger wires reduce the voltage loss. IMHO the size in this case is not really the issue, but the quality of the original wires and connectors is. They degrade, creating higher resistance, voltage loss and heat. If the starter cranks fast and freely you`ll be ok with your old wiring. Still you may think about changing it in future.

What is this clearance pick-up to the flywheel you speak of?

Simply said at a certain flywheel position the pick-ups send a pulse to the CDI unit which then controls when to fire the spark. The pick-up signal/output should be 0,5-0,6V when cranking, 1,6-1,9V at idle. As pick-ups and flywheel don`t touch the distance between them is important. The manual states 0,9+/-0,15mm. Good is 0,7-0,8mm for street use and 1,0-1,5mm for race use. If there are starting issues with cold engine one can reduce the clearance by 0,2-0,3mm. (if the issues are in the high revv range one can enlarge the gap by 0,2-0,3mm).

I tried flipping the run/kill switch while cranking.

This is only necessary if the bike doesn`t crank at all. If it`ll crank by flipping the kill switch this will indicate a possible problem with starter relay, ignition switch or run/kill switch. Same if the bike won`t crank but it will if you slap the starter relay slighty. All this is not your problem.

What spark plugs are you using ? It seems Pantah engines run better with Champions. However even if you`re using different ones you may experience some problems when running but it should still fire up.

G.

Thanks so much G, for taking some considerable time in your efforts to help me. It seems the very first thing is to yank the plugs, inspect them, and replace with a couple of new Champions. I am a big fan of good plugs and spend an absolute kings ransom on them for the Porsche.

If I am lucky, this might fix it. Sometimes I am spectacularly lucky. (For instance, I have never tried to fill a vehicle with oil without first checking the sump plug is fitted and torqued. )

Then I'll try the new coils and relay idea - I have an electrically competent workmate who also happens to have a Paso 906 (albeit a non-running one!) so I will ask him to give me a hand with that job.

Flywheel pickups would be my last option, as I have just put the thing back together again! ACK. (I was very careful not to change or alter anything under the alternator cover when it was apart, so they should not have moved from their previous "running just fine" clearances.)

Man, Higgy's signature really is correct isn't it? "Turning riders into mechanics since 1947". *sigh*

Mobius, getting stronger coils is definetely always recommendable but I`d first try the wiring mod only.
According to the manual the correct plugs for the 906 are the Champion RA6HC (0,6mm electrode gap - one should check also on new plugs). The Champions are the probably cheapest option but for some reason they work best. On the other side there are a few jap bikes that would run like sh** with Champions but purr like a kitten with NGKs. No idea why. It differes from engine to engine and ignition system to ignition system.
You may also try some starting aid spray. I use that quite often specially for waking up the bikes or lawn mower from hibernation. Good luck.

G.

higgy wrote:
Something is out of whack...false neutrals are not the norm even for Ducati

we will just have to disagree on this one - it's not just me, I've seen the subject come up over half a dozen times and have been out on a ride when it's happened to others - personally have had it happen on two 748's, one SS and my 750 Elefant. I would call that pretty conclusive but hey, waddo I know..

we will just have to disagree on this one - it's not just me, I've seen the subject come up over half a dozen times and have been out on a ride when it's happened to others - personally have had it happen on two 748's, one SS and my 750 Elefant. I would call that pretty conclusive but hey, waddo I know..

the fact that many flaws exist in many Ducati may make it typical,but even so typical is a long way from normal operation
The fact still remains something is out of whack. False neutrals are common issues in every single tranny ever made, not just your average duke

My paso ( immediatly blames the bike ) has a false neutral between 5-6 that more often than not . Ive never been able to figure why only this gear , a strip down ( for other reasons ) didnt shed any light .

Thanks to everyone for your great input!

I replaced the spark plugs and it fired up within 2 seconds on the first crank.

This starting issue has been interesting (and fairly frustrating too: What idiots thought it would be a good idea to make the same spark plug but with two different socket sizes?? 18mm Champions and 16mm NGKs! Aargh!) and I have read a lot about the electrical/starting issues for the Paso.

So, I have decided that I will replace the starter cables with the monster items described in another thread, and to install another relay. But those jobs can wait until winter, when the 928 is needed every day.

Right now it's time to enjoy the southern summer - and a damned good thing too! The price of 95 Octane just went over $2/litre - and the 98 I put in the 928 makes my eyes bleed. I put $160 in the Porsche the other day from almost empty.

When I started it, I also noted a total lack of crunching sounds - which I have heard in the past. Perhaps that single piece of engine case was the only one in there. I guess time will answer that question.

I remain super impressed with how knowledgeable and friendly everyone is here, and the time and effort people take to help out their fellow enthusiasts has bowled me over! I saved a huge amount of money doing it myself, and I still have most of the skin left on my hands - which is an added bonus!

There's only one tip I would give any new Paso owner before starting out on some home-based maintenance or repairs: make sure you have the necessary expletives for the job, and that you know how to use them correctly.

Cheers all.

Chris.

Most important of all - Good News Mobius! and just to re-iterate, this poster reckons that it is totally normal to stumble on a false neutral from time to time on your machine, so don't worry too much about it.

Yup. I think if I was 22 again, the false neutrals would really annoy me - because I would be riding at Mach 1 everywhere, risking life and limb. But now I'm so old I fart dust, and ride like it too - so it isn't really a big issue.

well its good you finally got her started etc etc. now you can let us know how you enjoy the 906 ride as we in the north are all frozen in. brrrrrrrrrr.

Chris, that`s good news. Actually almost a bit disappointing that the solution was so simple
But now you can help your friend to get his 906 running again.
Enjoy the ride !

G.

fully agree with G. time to get the other 906 up and running! good luck