Forth-coming article by the Paul K on his premature demise of the exhaust valve guides.
The following modification might be looked at as a tiny fix, but has saved me at least US$800 -- and perhaps even more if I initially knew about the following: One of the most annoying thing is when my Ducati refuses to start, as the starter slips and stutters. First I thought this might be a problem for bikes with lightened flywheel and/or synthetic oil, since installing the Nichols flywheel the starter-sprag has acted up three times... and it didn't matter how new the sprag was, soon enough it begun to slip -- often making it impossible to start the motor. As you might understand from reading some other entries of this web-site, I believe Jon Nichols is a brilliant mechanic (and manufacturer) who has this "urge" to make things work. So after collecting lots of info about the sprag, (I even purchased a crank-shaft seal for a Chevrolet which was rumored to contain a similar spring to the Duc-sprag's, which is essentially the weak part). Anyways, I brought my bike to Nichols' and started to badmouth his flywheel -- blaming it for making the sprags go awry. Uncharacteristically for him, instead of starting a verbal rebuttal of my accusations, Jon picked up a magnifying glass to look closer at the sprag and the spring which holds its rollers in place. He then found the opening where the spring is "screwed" together (into its loop). He cut the spring shorter and put it all back together and boomm.. just like that -- the bike started up as if having a new sprag. But infelicitously less than six months later, my starter acted up again.. this time I decided to do it myself. When looking at the sprag-spring I realized that it could have been cut a whole lot shorter than what Jon initially did -- making it much snugger. So I did, and needless to say; now it works like a charm.. and this was almost four years ago. If anyone has questions regarding a bad starter sprag, I'm happy to answer any question you have. The stuff you'd need in order to do a hack like this is a 30 mm wrench-socket for the flywheel, a tube of red lock-tie for the flywheel-nut -- and then, most importantly, make sure to put the sprag and the stator (amateur for the alternator) back the same way as you took it off. Note that both the sides of the stator look pretty much the same which makes it tricky to get back the right way if you forget to put a marker (or something) on it to indicate which side is which.. By the way, that Chevrolet crank-shaft seal-spring is too thick.. nice try though, eh..? 944 Conversion - John Deykes 28/02/2003 My 944 just seized.... Too much heat !! I ride most of the time off road, which is mostly higher speed desert riding. I also have rear gas tanks underneath the plastic side panels. The original elefant design limits the fresh air flow across the rear cylinder and I probably added to that. I don't believe a bigger oil cooler will help the head and cylinder that much although it couldn't hurt. The main issue is keeping the rear cylinder cool. With higher compression and added displacement the heating factor increases exponentially. These air cooled, 2 valve motors can be modified to get high horsepower on a Monster or SS with sufficient air across both cylinders (and high speed roadway use). With that said I wouldn't recommend changing the pistons at all. I had my heads ported/polished and SS valves and cams installed, the heads alone made more difference than the 944's did. I am currently having the stock 900 pistons and cylinders reinstalled along with all the damage caused by the 944's seizing. (Bent con rod, bent valves, cracked guides, and damaged head) I am trying to figure out a way to install a ram air type of system (carbon fiber "cups" on the sides of the fairing) to direct more air to the rear cylinder. I believe that the oil temperature gauge will tell you the temperature of the oil in your transmission. I do not believe the oil does much cooling of the cylinders and head (although I welcome responses from some of the engineers on the list), mainly just for lubrication of the valve train. I believe that the cylinders and heads have very wide temperature variations. I have heard of some people modifying the oil passages threw the cylinders and heads to increase the flow, and I thought that would be a good idea in theory, although I do not know how much the stock oil pump pushes. Like I mentioned before, the design of the Elefants with the big tank and the rear shock and frame push up against the rear cylinder, you can't get much air flow. If you Elefant riders out there are still planning on installing higher compression and/or larger displacement or have already done it, do everything possible to open up the back of the cylinder area. Maybe a smaller battery, then drill a number of holes threw the battery tray "you can't push air into a closed box". Richen up you carbs. Add as many additional scoops as you can. Only ride in the winter... Do not ride slower than 60 mph... I think you guys get the hint. Dave Bigelow wrote John I'm sorry to hear of your Elefant's difficulty, Lofgren and my buddy former dealer and long time Ducati racer have always been against much Elefant mods for that very reason. Too much heat, the oil drains back through the cylinders and around the sleeve inside of the finning hopefully carrying off some heat, it's not near as elaborate as BMW's oil cooling. There is some sort of thermal barrier to HP in 2v Ducati's, some of Lofgrens creations sport 2 oil coolers, and of course Ducati is adding or upgrading the oiling system on the redesigned 2v. What's your next plan ? I have a set of ported heads laying in my living room (eccentric bachelor) if you want to continue the insanity, it may save me from continuing mine. Hindsight being 20/20 I'd like to point out, that the C&H bikes probably had pretty much a stock 900ss motor with a 5 speed and a kick starter, on a good day they made 70/74 hp, your bike made over 80 easy and possibly more than 85, I'll bet an engineer could point out some huge difference in heat produced. I had my E944 on the local dyno which gave me less power than Lofgrens but the operator noted that only one 900 ss he'd tested had as much power as my Elefant and it had high compression pistons. My impression is the small port heads carburate better than the big ones, there's more velocity in them, it would be nice to try the stock cams with a 944 kit and just a touch more compression but the 900ss cams are probably much better as a off road cam. What I've always wanted to do was put a Paso 906 engine with carb's in a Fant but it would take more time and money than I want to throw at it. I probably have a set of stock cylinders and pistons around here someplace if you need them or have a plan. This little bit is for you and Alfred J, this whole episode is about why the KTM's are as heavy as your Elefants they have 95 hp and need that liquid cooling to maintain that power to weight ratio, if one threw bunches of titanium at them they'd be 25K each, but lighter. I hope I haven't offended anyone.I'm not an engineer. DB I did a little more research with my buddy since I started, his race F1's always sported ceramic on the tops of the pistons and hardcoat (frying pan coat) on the sides and he likes to paint teflon on street bike setups to prolong break-in. He also experimented ducting more air to back cylinder and claims a street 750 Paso oil cooled lost 50 degrees of oil temp with 2 small scoops and some hoses, maybe you haven't been on such a fools errand. DB
The following modification might be looked at as a tiny fix, but has saved me at least US$800 -- and perhaps even more if I initially knew about the following:
One of the most annoying thing is when my Ducati refuses to start, as the starter slips and stutters. First I thought this might be a problem for bikes with lightened flywheel and/or synthetic oil, since installing the Nichols flywheel the starter-sprag has acted up three times... and it didn't matter how new the sprag was, soon enough it begun to slip -- often making it impossible to start the motor. As you might understand from reading some other entries of this web-site, I believe Jon Nichols is a brilliant mechanic (and manufacturer) who has this "urge" to make things work. So after collecting lots of info about the sprag, (I even purchased a crank-shaft seal for a Chevrolet which was rumored to contain a similar spring to the Duc-sprag's, which is essentially the weak part). Anyways, I brought my bike to Nichols' and started to badmouth his flywheel -- blaming it for making the sprags go awry. Uncharacteristically for him, instead of starting a verbal rebuttal of my accusations, Jon picked up a magnifying glass to look closer at the sprag and the spring which holds its rollers in place. He then found the opening where the spring is "screwed" together (into its loop). He cut the spring shorter and put it all back together and boomm.. just like that -- the bike started up as if having a new sprag. But infelicitously less than six months later, my starter acted up again.. this time I decided to do it myself. When looking at the sprag-spring I realized that it could have been cut a whole lot shorter than what Jon initially did -- making it much snugger. So I did, and needless to say; now it works like a charm.. and this was almost four years ago. If anyone has questions regarding a bad starter sprag, I'm happy to answer any question you have. The stuff you'd need in order to do a hack like this is a 30 mm wrench-socket for the flywheel, a tube of red lock-tie for the flywheel-nut -- and then, most importantly, make sure to put the sprag and the stator (amateur for the alternator) back the same way as you took it off. Note that both the sides of the stator look pretty much the same which makes it tricky to get back the right way if you forget to put a marker (or something) on it to indicate which side is which.. By the way, that Chevrolet crank-shaft seal-spring is too thick.. nice try though, eh..?
My 944 just seized....
Too much heat !!
I ride most of the time off road, which is mostly higher speed desert riding. I also have rear gas tanks underneath the plastic side panels. The original elefant design limits the fresh air flow across the rear cylinder and I probably added to that. I don't believe a bigger oil cooler will help the head and cylinder that much although it couldn't hurt. The main issue is keeping the rear cylinder cool. With higher compression and added displacement the heating factor increases exponentially. These air cooled, 2 valve motors can be modified to get high horsepower on a Monster or SS with sufficient air across both cylinders (and high speed roadway use). With that said I wouldn't recommend changing the pistons at all. I had my heads ported/polished and SS valves and cams installed, the heads alone made more difference than the 944's did. I am currently having the stock 900 pistons and cylinders reinstalled along with all the damage caused by the 944's seizing. (Bent con rod, bent valves, cracked guides, and damaged head)
I am trying to figure out a way to install a ram air type of system (carbon fiber "cups" on the sides of the fairing) to direct more air to the rear cylinder.
I believe that the oil temperature gauge will tell you the temperature of the oil in your transmission. I do not believe the oil does much cooling of the cylinders and head (although I welcome responses from some of the engineers on the list), mainly just for lubrication of the valve train. I believe that the cylinders and heads have very wide temperature variations. I have heard of some people modifying the oil passages threw the cylinders and heads to increase the flow, and I thought that would be a good idea in theory, although I do not know how much the stock oil pump pushes.
Like I mentioned before, the design of the Elefants with the big tank and the rear shock and frame push up against the rear cylinder, you can't get much air flow. If you Elefant riders out there are still planning on installing higher compression and/or larger displacement or have already done it, do everything possible to open up the back of the cylinder area. Maybe a smaller battery, then drill a number of holes threw the battery tray "you can't push air into a closed box". Richen up you carbs. Add as many additional scoops as you can. Only ride in the winter... Do not ride slower than 60 mph... I think you guys get the hint.
Dave Bigelow wrote
John I'm sorry to hear of your Elefant's difficulty, Lofgren and my buddy former dealer and long time Ducati racer have always been against much Elefant mods for that very reason. Too much heat, the oil drains back through the cylinders and around the sleeve inside of the finning hopefully carrying off some heat, it's not near as elaborate as BMW's oil cooling. There is some sort of thermal barrier to HP in 2v Ducati's, some of Lofgrens creations sport 2 oil coolers, and of course Ducati is adding or upgrading the oiling system on the redesigned 2v. What's your next plan ? I have a set of ported heads laying in my living room (eccentric bachelor) if you want to continue the insanity, it may save me from continuing mine. Hindsight being 20/20 I'd like to point out, that the C&H bikes probably had pretty much a stock 900ss motor with a 5 speed and a kick starter, on a good day they made 70/74 hp, your bike made over 80 easy and possibly more than 85, I'll bet an engineer could point out some huge difference in heat produced. I had my E944 on the local dyno which gave me less power than Lofgrens but the operator noted that only one 900 ss he'd tested had as much power as my Elefant and it had high compression pistons. My impression is the small port heads carburate better than the big ones, there's more velocity in them, it would be nice to try the stock cams with a 944 kit and just a touch more compression but the 900ss cams are probably much better as a off road cam. What I've always wanted to do was put a Paso 906 engine with carb's in a Fant but it would take more time and money than I want to throw at it. I probably have a set of stock cylinders and pistons around here someplace if you need them or have a plan. This little bit is for you and Alfred J, this whole episode is about why the KTM's are as heavy as your Elefants they have 95 hp and need that liquid cooling to maintain that power to weight ratio, if one threw bunches of titanium at them they'd be 25K each, but lighter. I hope I haven't offended anyone.I'm not an engineer. DB I did a little more research with my buddy since I started, his race F1's always sported ceramic on the tops of the pistons and hardcoat (frying pan coat) on the sides and he likes to paint teflon on street bike setups to prolong break-in. He also experimented ducting more air to back cylinder and claims a street 750 Paso oil cooled lost 50 degrees of oil temp with 2 small scoops and some hoses, maybe you haven't been on such a fools errand. DB
