colint
Registered user
Anyone out there with any experience in twin plugging is the ignition timing on a twin plus conversion the same as the standard timing R100GS
Twin Plug ignition timing
- Thread starter colint
- Start date
Beemerboff
Registered user
You need a different curve, and a bit less advance.
The curve on the Boyer Micro power is excellent, and your dyno guy will set the advance for you - the optimum figure varies about 6 degrees from bike to bike.
But get it right and it works real well mine pulls like a train from 2300 revs in top.
The curve on the Boyer Micro power is excellent, and your dyno guy will set the advance for you - the optimum figure varies about 6 degrees from bike to bike.
But get it right and it works real well mine pulls like a train from 2300 revs in top.
Are you thinking of having it done or do you have a bike with it already done?
If you're thinking of having it done I wouldn't bother. They're are easier and cheaper ways of getting more bang for your buck.
colint
Registered user
Just bought an airhead that has been converted it runs fine but just something to bear in mind for the future it has the Motorworks replacement "bean can"
Motorcycle Michael
Registered user
fayeslane
Registered user
I 've got a twin plugged R80g/s which performs very much like a single plug 80 but with more parts, bottom plugs vulnerable and the integrity of the head compromised. Best & easiest performance mod I have don is to chuck a set of Moorespeed pistons into an R100GSPD.
Motorcycle Michael
Registered user
I thought your Cafe racer was a Moorespeed? when Moorespeed were building my engine I spoke to Richard about twin plugging and was told there was no need to Twin plug his engines.
I fitted a twin plug setup a few years ago to an airhead and then spent weeks messing about with ignition timing - everything from bending ears on the bean can to various settings on the timing and never managed to get a decent compromise on the timing. In the end I simply turned the bean can by hand until it got the best tickover and acceleration and then checked it with a strobe. It was virtually bang on the standard timing mark. The only discernible advantage was that it had a very good tick over. There was no obvious improvement when the bike was put on the dyno. If I retarded the ignition top end power was compromised with little or no improvement to the bottom end power. I gave up in the end, put the bean can ears back where they started from, and ran the bike on the standard ignition timing.
I've always been a fan of the Boyer Microdigital ignition but a recent experience with there twin plug unit (mirrored by Roger Chatterton) has left me with some doubts about their units.
The biggest issue with twin plugging is ignition timing. You need less advance at lower RPM. At higher RPM the twin plugging works against you so you need more advance further up the rev range (that's why the bean cans advance unit needs the "Ears" bending to allow more advance) in practice how do you quantify it? unless you have complete access and control of a Dyno you are never going to find a setting that works. The hassle of adjusting the bean can means you will have to strip the unit away from the Dyno before returning and trying something else - this is going to cost a small fortune. The only other option is to opt for an expensive, programmable ignition that you can adjust with a laptop but again it's lots of dyno time and hundreds of £
There's a good article on Gunsmoke about Twin Plugging http://www.gunsmoke.com/motorcycling/r100gs/dual_plug/ You can pick up on the authors frustration over the ignition.
I fitted a twin plug setup a few years ago to an airhead and then spent weeks messing about with ignition timing - everything from bending ears on the bean can to various settings on the timing and never managed to get a decent compromise on the timing. In the end I simply turned the bean can by hand until it got the best tickover and acceleration and then checked it with a strobe. It was virtually bang on the standard timing mark. The only discernible advantage was that it had a very good tick over. There was no obvious improvement when the bike was put on the dyno. If I retarded the ignition top end power was compromised with little or no improvement to the bottom end power. I gave up in the end, put the bean can ears back where they started from, and ran the bike on the standard ignition timing.
I've always been a fan of the Boyer Microdigital ignition but a recent experience with there twin plug unit (mirrored by Roger Chatterton) has left me with some doubts about their units.
The biggest issue with twin plugging is ignition timing. You need less advance at lower RPM. At higher RPM the twin plugging works against you so you need more advance further up the rev range (that's why the bean cans advance unit needs the "Ears" bending to allow more advance) in practice how do you quantify it? unless you have complete access and control of a Dyno you are never going to find a setting that works. The hassle of adjusting the bean can means you will have to strip the unit away from the Dyno before returning and trying something else - this is going to cost a small fortune. The only other option is to opt for an expensive, programmable ignition that you can adjust with a laptop but again it's lots of dyno time and hundreds of £
There's a good article on Gunsmoke about Twin Plugging http://www.gunsmoke.com/motorcycling/r100gs/dual_plug/ You can pick up on the authors frustration over the ignition.
You can say that again Rob .....
..... least I got a full refund ! I'm certainly in no hurry to repeat all that mucking about ! And , if my bike hadn't been twin plugged when I bought it, I probably wouldn't bother doing it either. My other GS PD is the original single plug, and when riding it I can't say that I notice a whole lot of difference between the 2 bikes. Twin plugging does give you a spare coil though !!
Motorcycle Michael
Registered user
I own 2 R100R's. One twin plugged,the other stock. They were both in standard trim at the time of this comparison.
The twin plugged bike was ridden to Germany by a previous owner for Wunderlich to convert,I have the receipt somewhere,and the owner then went on a European tour!
Interestingly,Wunderlich also modified the airbox with shortened tubes and holes in the top. I tried this later on the purple bike but couldn't get it to work.
Having ridden them back to back I can say that the twin plugged bike was better in every respect,even at twice the mileage of the single plug bike and I still own it today. It's the black Cafe Racer at the front.
For me at least,twin plugging works but I agree that ignition timing is critical. I later twin plugged the purple R100R ,middle bike,and it took me ages to get it right. Worth it though.
Mike.
The twin plugged bike was ridden to Germany by a previous owner for Wunderlich to convert,I have the receipt somewhere,and the owner then went on a European tour!
Interestingly,Wunderlich also modified the airbox with shortened tubes and holes in the top. I tried this later on the purple bike but couldn't get it to work.
Having ridden them back to back I can say that the twin plugged bike was better in every respect,even at twice the mileage of the single plug bike and I still own it today. It's the black Cafe Racer at the front.
For me at least,twin plugging works but I agree that ignition timing is critical. I later twin plugged the purple R100R ,middle bike,and it took me ages to get it right. Worth it though.
Mike.
Attachments
Beemerboff
Registered user
I set the timing on my twin plugged 1000cc R80G/S the same way as Rob, just back from fastest tickover then acceleration runs up a decent sort of hill, and I ended up with the mark only just visible, 26/27 degrees advance.
Which sort of supports the guys who tell you that the correct advance varies by up to 6 degrees, bike to bike.
But I dont know what pistons were fitted or other mods were made when the PO fitted the 1000cc barells and twin plugged it at the same time, but I do know the Boyer Micropower works much better than whatever he did to the ignition.
I have used Boyers for years without any problems, the main weakness with them seems to be that the are not sufficiently foolproof , and are too easily damaged by inexpert handling.
Which sort of supports the guys who tell you that the correct advance varies by up to 6 degrees, bike to bike.
But I dont know what pistons were fitted or other mods were made when the PO fitted the 1000cc barells and twin plugged it at the same time, but I do know the Boyer Micropower works much better than whatever he did to the ignition.
I have used Boyers for years without any problems, the main weakness with them seems to be that the are not sufficiently foolproof , and are too easily damaged by inexpert handling.
Similar threads
