New ignition system: need advice!

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81mhr900ss
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New ignition system: need advice!

Post by 81mhr900ss » Fri May 24, 2019 12:10 pm

I am waiting for my new Sachse ignition to arrive for my 81 MHR; the new Dyna coils and HT leads are here as is the new Shendingen regulator. I had read a number of positive references of Shendingen regulators being used on older bevel 900s and figured that my old Ducati Electronica regulator may not be the best protection for the new stuff. I just test-fitted the Shendingen FH200AA regulator and it's way too long to fit on the frame where the old one goes; it interferes with the battery. Have any of you installed a Shendingen regulator and if so, where did you put it? I'm probably going to relocate the new coils under the tank so up front may work but I have an oil cooler there which makes things a little tight.

While you are at it if you have any recommendations regarding relocation of the Dyna coils and the Sachse box, I'm interested to know. I've seen several installations already; up front, back under the tank.

Thanks in advance for any help.

Rick

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Gardner
Diana
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Location: Davenport, Ia

Re: New ignition system: need advice!

Post by Gardner » Mon May 27, 2019 7:21 pm

When you time the Sachse ignition you will need to know when the front piston is exactly at the top of it's stroke. I used a 1 inch travel dial
indicator on a magnetic base with a 2 inch extension to reach down the spark plug hole. They supply an led indicator light that you temporarily
hook up and then you watch the red led and the dial indicator at the same time as you are rotating the crankshaft. When the red led goes out at the same time the piston is at the end of it's stroke you tighten up the trigger wheel setscrews and that's it. You have to remove the clutch/timing cover every time you adjust the trigger wheel but it doesn't take too long. I use a short 8mm allen head bolt in the end of the crankshaft to rotate
clockwise. Just don't forget to take that bolt out when your'e done! Take both spark plugs out to enable a smooth rotation. I do put the spark
plugs in the caps and lay them on the head fins so they spark. I once worked on an ignition that would be damaged if you didn't do that, so now
I just do it on all of them. I also use a piece of steel around 10 inches tall to attach the magnetic base to. Sure runs smooth and idles nice
when your'e done.
1978 SD Darmah
1979 SSD Darmah
1981 900SS
2017 Desert Sled
1982 Bimota HB2

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81mhr900ss
Mach 3
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Re: New ignition system: need advice!

Post by 81mhr900ss » Mon May 27, 2019 10:56 pm

Thanks Gardner: As you are aware, the Sachse instructions are not good so every little bit of advice will help. The mounting instructions are probably the worst I've ever seen for anything I've ever bought:

3 Mounting
• Remove all Bosch components, the trigger wheel on the crankshaft, too.
• Mount the new sensor plate again (with the original 9mm guide sleeve on the bottom).
• Put the wheel guide sleeve on the crankshaft and then put the magnet wheel to the stop
on the sleeve.
• The M30 nut can now again be mounted (with medium strength thread lock).
• The sealing of the cable feedthrough occurs by the provided screw connection.


Maybe this will make more sense when I have the parts in my hand; it's the "wheel guide sleeve" stuff that doesn't make sense yet.

I squeezed the new Shendingen regulator in the original spot a few days ago and repurposed the original coil brackets for the new Dyna coils; it will be attached to the old frame brackets for the Bosch units. It's already taken a whole week and a bit since my order and the Sachse unit isn't here yet but should be any day now. Tomorrow, I'll get the bike prepped for the Sacshe installation.

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Gardner
Diana
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Location: Davenport, Ia

Re: New ignition system: need advice!

Post by Gardner » Tue May 28, 2019 5:50 am

The wheel guide sleeve is a bushing with a key way that slides on the crankshaft. The trigger wheel slides onto it and the setscrews are tightened after timing it. In the future if you have to remove it, you just slide it off the crankshaft as one piece without disturbing your timing.
I find the key way is too tight and do a little adjustment with a needle file. Otherwise you would have to tap it on the crankshaft and future
removal will be tough. I added a small plate of aluminum under the tank to attach the velcro they supply. I use ignition curve setting 7 but
you can play around with the others. The sensor plate just replaces the old pickups.

The sealing of the cable feedthrough occurs by the provided screw connection. They supply a really nice stainless fitting to replace the plastic one for the cable to pass through the cover. I slide some 1/4 heat shrink tubing over the white cable and shrink it on to make it look normal.
1978 SD Darmah
1979 SSD Darmah
1981 900SS
2017 Desert Sled
1982 Bimota HB2

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81mhr900ss
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Re: New ignition system: need advice!

Post by 81mhr900ss » Wed May 29, 2019 12:00 pm

Thanks again. I just removed the old pups they really are in very good condition, even the wiring is still flexible. I tested the pups multiple times and got good, consistent resistance (228 and 232 ohms) even when wobbling with the pup wires; only 25k kms on this bike. I fiddled with a jewelers' screw driver to try and release the pins from the connector but gave up and cut the wires so that I could remove the old pup block. Maybe it will be of use to someone trying to restore a bike to OEM spec. Maybe I'll recoup some of my Sacshe/DynaTek/Shindengen expenses!

I was also thinking about making the white wires black using sheathing but none of my local stores have any so heat shrink may be the way to go.

wdietz186
Cagiva Alazzura
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Re: New ignition system: need advice!

Post by wdietz186 » Thu May 30, 2019 6:33 am

Just a reminder, the engine turns clockwise[ as viewed from the left side of the bike] not like the belt drives or most everything else out there.

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81mhr900ss
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Re: New ignition system: need advice!

Post by 81mhr900ss » Sun Jun 09, 2019 6:52 pm

Some closure: the Sachse system was a really easy fix. Testing and timing is really easy (despite what I read in earlier threads) and I ended up attaching the little black box to the rear mudguard adjacent to the new Shendingen regulator. Bike fired up easily on the first kick. I'll do a write-up once the bike is broken in a bit.

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Gardner
Diana
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Re: New ignition system: need advice!

Post by Gardner » Mon Jun 10, 2019 6:03 am

That's awesome! Glad you're getting some riding in.
1978 SD Darmah
1979 SSD Darmah
1981 900SS
2017 Desert Sled
1982 Bimota HB2

andybaggies
Cucciolo - the Lil Pup
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Re: New ignition system: need advice!

Post by andybaggies » Sat Jun 15, 2019 11:55 am

Good to hear some feedback on the Sacshe as I've just fitted & timed the exact same system to an engine that's still on the bench and it was as easy as the guys mentioned.

I suppose the only difficulty is finding exact TDC of the front pot as all timing is taken from this point, the system measures the speed of the crank to adjust timing rather than rely on pickups. I used a timing wheel & a torch plus a good 40 minutes farting about setting & checking & rechecking TDC. BTW I have one of these which at first seemed quite pricey but has since proved absolutely invaluable https://www.lasertools.co.uk/product/5181 and of course cheaper on ebay.
I use ignition curve setting 7
That's the one I thought of using as it's the closest to the Bosch's steps but I notice it has 2 more degrees advance above 4K. How good were these steps in the first place? I see Sachse's default setting is curve 2

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81mhr900ss
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Re: New ignition system: need advice!

Post by 81mhr900ss » Sun Jun 16, 2019 9:50 pm

I had promised a proper description of my new electrical set-up and I will do this soon but I wanted to respond to Andy's comments regarding set-up of the Sachse system. As anyone who has looked will know, the Sachse instructions are on-line and suck; all they really need is a light edit and a few more pictures. After reading as much as I could on the Internet I ordered the system and as expected, once I had the bits in hand, things were more clear.

I removed all the old Bosch bits, cleaned everything and then very patiently fitted the "wheel guide sleeve" onto the crankshaft. As advised by someone who had done this before, I did not force the sleeve onto the shaft and over the key; I used a small file to remove a tiny amount of metal from the key way on the sleeve until the sleeve was a tight, by-hand, push fit. If I had not done this, there would be no way to remove this sleeve once it is on the crankshaft. I did this job a little bit at a time until the sleeve pushed on tight but could also be pulled off by hand; there was no slack; tight fit! One watch out is the little Woodruff key; it's loose enough to pull out by hand once the Bosch trigger wheel is off so if not careful it could, conceivably, fall out and get lost.

I had already set-up the front pot to TDC by chopstick; yes chopstick. This meant that the woodruff key was already pointing to front pot TDC. I added the magnet wheel and aligned the ID timing mark with the Woodruff key and loosely tightened one of the three magnet wheel grub screws. I pushed the magnet wheel on far enough so that when the crankshaft lock nut was in place it would not be touching the magnet wheel; the Sachse manual explains the importance of magnet height relative to sensor position for the system to work. Using a flat edge across the crank case and a small ruler, I estimated how many mm the magnets were sticking out from the edge of the crankcase.

I replaced the old Bosch pups with the the new Sachse sensor plate and used the same technique to estimate how many mm the sensors were inside the edge of the clutch case cover. I can't remember the number but was surprised to find them exactly the same, i.e. if the magnet wheel is placed just far enough on the wheel guide sleeve so the lock nut can be tightened and not touch the magnet wheel, the magnets and sensors will be aligned. To test, I put the cover on and my little Sachse test LEDs lit up and shut off just fine as I rotated the crank. A good time to mention my crank rotation tool; a hex head bolt from my bolt collection that fit perfectly onto the end of the crankshaft and an Allen key. Cheap and worked fine.

Now is where I'm probably going to get some flak but whatever, my technique worked. I did not have timing lights and a dial gauge. Someone wrote that the job can't be done without a dial gauge measuring the front pot TDC but using my chopstick stuck into the sparkplug hole, I could feel and see very clearly exactly when the piston stopped moving up and started moving down again. I set the pot at TDC, pulled the case off, loosened and turned the magnet wheel the tiniest amount to better align the ID mark on the magnet wheel with the crank Wooduff key and then put the casing back on, turned the crank and watched the test LEDS go on and off. The red light went off exactly at chopstick TDC on the front pot and again on the rear pot TDC. I cranked the motor maybe 10 times with perfect results. I then pulled the casing off, Loctited and tightened all three magnet wheel grub screws, put the casing back on and tested again; nothing had shifted. I bolted the casing on and tested again; nothing had shifted.

A day later, the bike fired up first kick and was at last running smoothly and evenly on both cylinders. I'm in limbo for another few days due to a registration/insurance delay but I did get to ride the bike briefly and it felt great; no misfires, rumbles, just smooth acceleration. I will report back once I've blown out the cobwebs.

I also replaced my old ND coils with 5ohm DynaTek ones, fitted up under the tank using the original hanger pieces from the ND coil block ally frame plus a few new bits I made myself and frame bolt points and old bolts from the Bosch units mounting plates. The Sachse unit is Velcroed to the rear mudguard adjacent to the new Shindengen FH020AA reglulator and behind the new fuse box (Amazon). The battery is also new.

Pictures:
Shindengen regulator - a tight fit, re-oriented with the the plugs exiting top left, attached to the original frame plate with one new hole and an ally bracket behind it. It clears the battery by about 3mm.
Image

Sachse unit, regulator and fuse box. Note the new ground point:
Image
Image
Image

DynaTek coils and HT leads with new NGK plug caps:
Image
Image
Image

Custom crankshaft rotation device:
Image

Speedrocker
Mariana
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Location: Northern Germany

Re: New ignition system: need advice!

Post by Speedrocker » Mon Jun 17, 2019 7:00 am

Nice, clear and cool report!
I´ll keep it in my mind,..whenever i `ll have some serious trouble with my orign. ignition-system, i will probably change it to an Sachse system...
...and i must repectfully say: Your MHR is clinically clean ! Top Bike !! Congrats!

Greets,
Joe

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81mhr900ss
Mach 3
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Re: New ignition system: need advice!

Post by 81mhr900ss » Mon Jun 17, 2019 9:21 pm

Hey Joe: The red zip ties are critical; red makes things faster!

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Craig in France
Cagiva Gran Canyon
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Re: New ignition system: need advice!

Post by Craig in France » Tue Jun 18, 2019 12:55 am

Excellent post, Rick. Glad to hear things are working well and thanks for taking the time to do the write-up.

Appreciated.

Craig

andybaggies
Cucciolo - the Lil Pup
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Re: New ignition system: need advice!

Post by andybaggies » Wed Jun 19, 2019 11:03 am

Thanks for the full description Rick but it is worth noting there is an updated installation guide on the Sachse web site, see https://www.elektronik-sachse.de/shops ... bosch.html I found it did have a little more information & photos that made it quite easy to follow – a couple of read throughs before diving in helped a lot.
the Sachse manual explains the importance of magnet height relative to sensor position
On my Darmah this was pretty easy to do as the engine is still on the bench & with no starter motor or starter cover fitted, it was just a case of peering in and visually checking the relative positions. I did fully tighten the crank nut up & as you say it was bang on when the magnet wheel was pulled up to the washer. One thing to note is the bolt that held the original Bosch pickups, the one that goes through the clutch cover on the Darmah, was too large for the thread in the new pickup board. Easily rectified with a new bolt & spring washer mind.
I had already set-up the front pot to TDC by chopstick; yes chopstick
After having tried this method before in my youth and snapping too many of them & then trying retrieving the debris from inside the bore I decided a timing wheel would be a wise investment. It fits nicely on the aforementioned crank turning tool. At this point I almost felt professional, ho hum.

I just connected the ignition box up to a battery (with no coils fitted) & yes, it is a bit of a faff putting the cover on, checking when the led extinguishes, taking the cover off adjusting, putting the cover back on, checking again etc.

But it’s no more of a faff than other Ducati shimming jobs I can think of…
I also replaced my old ND coils with 5ohm DynaTek ones
Yep, I ordered a set of those as well & I’m just waiting for the frame to come back from paint so I can set to on the rewire. I’m keeping the old Darmah bracket at the headstock which has been modified to take the new connectors I’ve bought.

Originally where wires were joined together this was usually done on the connector terminal which always makes me wince as it looks all too crammed together. So where appropriate I’m planning on joining them away from the connectors with a single wire going to the terminal(s) and, now the airbox is going, this can be done in the space behind the bracket. I’m also planning on using a busbar with all earths coming back to it rather than relying on the frame (and having to scratch off the freshly applied paint).

Placement of the coils & ignition box is yet to be decided & your photo showing the latter on the rear mudguard does look to be the best option.

And finally a couple of follow on questions, does the Shindengen have an output for use with a generator light? & what map did you use on the Sachse?

Andy B

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81mhr900ss
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Re: New ignition system: need advice!

Post by 81mhr900ss » Wed Jun 19, 2019 9:10 pm

Hey Andy: you need beefier chopsticks!
A couple of things I missed mentioning:

I had read an earlier Sachse installation write-up that showed the old tab washer being reused for the crank lock nut but this made no sense to me; the old tab washer has an indent on the ID that locks/aligns it with the key slot but it can't do this with the Sachse wheel guide sleeve so it would just be a washer, not a lock washer; folding the tabs wouldn't be doing anything. I used Loctite on the nut and torqued it to 88ftlbs, the old Ducati manual spec. Of note my old Haynes manual spec for the same nut is wrong at around 58ftlbs.

Ignition box location: read Rob's set-up on the Ducati MS Forum. he squeezed his Sachse box up between the headstock and the old Bosch plates, using the detachable Bosch plates to hold it in position. Very cool but, the thing can't be accessed without removing the tank and when I tried, mine would not fit; it was tight by less than a mm. With all the old stuff gone, there's loads of room under the tank but I figured stcking it to the rear fender was really easy and really accessible.

I currently have the #5 curve chosen but only because I had read somewhere that someone liked this setting after trying several others.
I should note that I just got my bike registered and insured TODAY!!! YEAH! Test riding and relearning how to ride a bike tomorrow.....

I'm not sure I understand your generator light question but I will try to answer. The GEN lamp doesn't stand for generator, it stands for "general" On the MHR, the Gen lamp gets its power when the ignition switch is turned on; its simply states that it is seeing switched 12V from the battery, bike running or not. The later electric start models, including the Darmah are an exception; the GEN feed on a Darmah comes from the Motopiat volmeter. Low volts kills electric starter sprag clutches; I'm guessing that this is why the "Gen" lamp was repurposed on these models.

There is only one extra connection on the Sachse unit, #7, that sends a signal to an electronic tacho should you wish to install one.

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