Ducati Monster Forum

I found the oil based heater didn't work and had hideous plumbing on my first Monster. I've heard the electric heating system doesn't work much better at only 3 Watts. The coolant version used by Kawasaki looks like it should work but still doesn't. A buddy's ZXR900 still froze up with coolant routed through the bowls. You would think Ducati's oil jacket system would work better, but an air/oil cooled bike can take quite awhile to truly warm up in cold weather. So a warm liquid jacket doesn't seem to work which brings me back to the electric version.

Anyone beefed up the electric version of the heater? They have been used on cars for years and Triumph has used them on their carbed bikes until changing to EFI recently. Maybe a manual switch system too. Is it doable without too much strain on the bikes electrics? How many watts can the oem element take and how do you send more juice through it?

Of course not an issue with flat slide or round slide carbs. CV carbs are prone to it and I remember the Harley CV carbs also freezing up in winter, so everyone got an S&S carb. I'm asking since I have gone back to a CV carb on the Monster.

The only time I have had an issue with my M900 with the CV's is in weather about 38-40F degree and humid weather. It only happened a few times.

I've been told by folk who have lived up there and down here that we have a very "wet cold" here at higher temps that is not the crisp dry really really cold you guys get. A few people have told me that. It will be interesting to see how the bike goes this winter with the closed (only half drilled) airbox and CV carbs. The oil type heaters on my first M900 were fitted under warranty but did nothing.
I wonder if with the right wiring, relay, etc the electric heaters could really warm things up?

I think you have to believe that it's actually the drop in temp of the fuel atomizing that's causing the freeze up.

I have a drilled airbox on mine and it did it.

I've seen ice coating an alloy inlet manifold once. Crazy strange. What was that about? It only melted when the bike sat at idle.

Over the years I have noted that big bore engines with CV carbs are more prone to it than small engines. Someone suggested that long manifolds don't help, but I've seen bikes with short rubber spigot type manifolds freeze up too, so its the CV factor with its high air velocity and cold humid air that should be the culprit. I've seen it at 16-17 deg C in the local hills.

If the car carb heaters worked surely the bike ones could be made to work?

Any time you have expansion you have a drop in temp.

The volume of fuel and air expanding after being forced through the carb venturi and moving through the manifold cools it to the point where the moisture in the air surrounding the manifold condenses and freezes.

At idle the volume drops as does the cooling effect so it melts.

Thanks for that explanation. Clearly my hot science teacher distracted me in class. [laugh]
The CV piston function must exacerbate that effect. We ran round slide, flat slide and straight butterfly carbs with no ill effect on our Harleys. We ditched the Keihin CV 40s from our Harleys and the freezing stopped.

The vacuum isn't strong enough to break the ice film so the slide stays up. All the other scenarios are mechanical with fairly strong return springs

Another reason to stick with the heavier stock springs (besides piston "flutter'). Doug Lofgren seems to like them.

Bruce liked the soft springs.

Both of those guys know their stuff.

Just to confuse us all, that'd be right! [laugh]

Howie would surely know if it's doable.
Calling Howie to the blue/white electrical phone... [popcorn]

we had a lot of issues with, especially up your way and further into the hills.

we wrapped manifolds in header wrap and covered them with heatshrink.  we made up folded aluminium plates to cover oil coolers.  we had a few people run the harley additive in the fuel, which seemed to help more than anything else.  or plain metho.

i was wondering if a plate shielding the float bowls would work in conjunction with the kits to retain heat, but then all the i4 applications that do this have carbs behind the engine.  the paso had a kit that picked up inlet air from a shield plate sitting on top of the horiz cylinder, so maybe you need to rig up a hot air intake.

one of the worst (not our customer) was a 750ss that lived up the spur way.  he was a real pita allegedly.  we had an m900 owner who demanded (unsuccessfully) we inject his carb bike.

i don't recall 600 doing it so much, but certainly 750 did.

when we first had issues we got told "they've never had these issues before, even in italy".  but then the 1993 900ss parts catalogue has the heater kit in it.  they used to say the same thing about cracking ss frames.  what is it with manufacturers and denying problems.  no wonder they hate the internet.  can't bullshit people anymore.

If the element is 3w and is supplied 12v there really isn't much you can do. If it's supplied less, you could increase the voltage to increase the output.

I doubt that's the case.

Must be a way of tricking that with an electronic device you reckon?


Morning Brad.
Thanks for chipping in.
Back in 96-97 I had a red hot go at the Importer selling me FCRs at cost because the heating kit didn't work. Pretty much told me to get make the beast with two backsed. [laugh] Worth a try ;D.
The Importers engineer consultant suggested the anti freeze additive. He claimed that our fuel didn't have the Northern Hemisphere winter additives to stop carb freezing. A Shell consultant told me the recipe for fuel changed seasonally anyway.
You'd reckon the electric version if given enough juice would work. In the end I decided to use exhaust heat wrap on the manifolds. I thought about making a winter manifold sock that could Velcro on. Never got around to it but might try something like that now. Interesting the electric version came out later.

The element might decide it doesn't like being tricked and decide to burn up. ;D

Not good in that area [laugh]

I think the manifold sock method might have to be employed.

What you believe is true.  An open air box having affecting this is surprising to me.  Maybe it shouldn't be.  No freeze since mine was opened about 11 years ago.  Same drilling as yours.

No idea if it is doable or how to accomplish this.  Sorry.  Gotta say my bike went pig rich on the dyno when the throttle was wacked with soft springs and seemed a little crisper on the street with stiff springs.

Carb sock it is! [laugh] If you don't know I wont try! ;)

On springs, Im running Factory Pro (mid range stiffness according to Brad and they feel it) but may even go back to stock. The DJ springs are way soft. Are you running DJ springs or FP?

Mine have DJ

Posting this bit is a redo from quite awhile ago.

Iirc, cleaning up the manifolds with a textured finish helped reduce icing.
Not only do the oem manifolds have casting dags and rough sections, but shiny sections with an almost mirror like finish. Very inconsistent in finish. They also had some crappy angles with the casting.
Anyway, anecdotally I noticed a difference after "porting" them with better radii and texture. I was surprised at the result, but probably shouldn't have been. Maybe coincidence, maybe another adjustment to the jetting or spring change helped, but it was so long ago I'm not sure.

you could just refit the fcr.

One day. Dad's rules. ;)

Total nerd moment for me here.DP is on the right track with his explanation. I know with steam ejectors used to create vacuum, if the saturation point of the steam driving them is too high, they ice up because of the change in velocity, not necessarily volume. In my brain, that translates well to damp cool air blowing through venturi. Add in the evaporative cooling effect of gasoline going from liquid to vapor, and there's enough drop in temp to try to ice up whatever residual moisture is there.

I like in Montreal canada and I have to ride in severe from time to time....

I just  take my hairdryer and put it in the airbox .. ;D.  . 1 or 2 min latter .... vroooum...  [bow_down]

When the wether is cold I cary it in my backpack when I ride ....just in case....

You would be suprise  how many exterior electrical outlets are out there ...lol... [thumbsup]

The situation we are talking about here is caburator freezing.  Happens while riding at barely above freezing and high humidity.  Venturi affect cools the moist air rushing through the carb enough to cause ice.  Colder, not enough moisture in the air to cause the problem.  On car carbs the throttles tend to freeze, on our Mikunis the needle freezes.  Flat sides seem to rattle the ice away.  A hair dryer would work well, but you would need a really long extension cord  :P

If I remember correctly, the one time I had freezing was in early fall, so maybe winter fuel additives here in the NE US do help.

Hey 100. :)

As Howie said, starting is no problem, but freezing carbs are when you are riding. Do you have any ideas about strengthening the electric carb heaters on some models? The element does not get hot enough to make much of a difference. The only thing I can think of is to wrap the inlet manifolds in heat insulation material to keep them warm in winter.

we tried the wrap, it made 3/8s of make the beast with two backs all difference to those that had real issues.

Have you seen any of the electric carb heaters here?

they were introduced in 99 or 2000 maybe.  2000 parts list shows them.