bypassin the carb warmer?
 

I need to know if anyone has tried to remove the carb warmer lines from their bike? It seems to me that the fluctuations of performance could be linked to the temp of coolant running in the carbs... I am having problems like Uchi
and thought of the coolant heaters on the carbs , not sure I have seen this before on anyother bikes
please let me know what ya think...

NO
do a search for more info, no gains to be had.

lol but... but ... ok searched and not sure if anyone was definate on its function

Been over this at least a dozen times over the years. Waste of time. Nothing to be gained. Unless you've 1) disconnected the coolant tubes from the carbs and 2) are riding in sub freezing temps, problems you're experiencing have nothing whatever to do with coolant through the carbs.

The purpose of running coolant through the carbs is to prevent freezing in cold temps.

In other words, you can get in trouble if you disconnect them and ride in cold temps. In warm temps it doesn't matter, but there is never anything to be gained by going without them.

ok tell me what other bike uses this method ?

I am now curious , I believe you guys , but I really have no recollection of carb warmers on other bikes. Anyone know of one?

Actually unless you are at very low temps they are not warming anything... The flow there is absolutely nil in many cases...

I have seen it on a couple of Ducati's and Kawazaki vulcan has them, as well as BMW f650... I can keep going for a while... These are just bikes that I have worked on...

Hmmm, reduced complexity comes to mind.


Rex

the honda engineers mite have been trying to keep the carbs warm to preheat fuel, you get a better combustion when you do so.due to the better atomization that fuel gets at higher temps. you wont see preheating fuel on fuel injected bikes do to the high pressure at witch the injectors disperse the fuel into the cylinder.
that high pressure atomizes the fuel better than preheated fuel on carbs. hence why injected bikes make more horsepower. atomizing is just a fancy way of saying the mixing of fuel and air, the more you can break down both in to smaller parts, the better the fuel and air will mix together, the better of a combustion you can get witch produces more horsepower.

I guess you could look at it that way. I meant nothing to be gained in reference to the idea that carbureting problems could be alleviated.

CBR600F3s had them. Probably other bikes too, but that one comes immediately to mind.

Look at the throttle body of your fuel injected car. They all have coolant lines running to the throttle body for 2 reasons:

1) On older cars with carbs, the intake manifold was heated with exhaust gas to give better driveability during warm-up and to prevent carburetor icing in cold weather, below 40F. Pretty much the same for EFI, except coolant is used.

2) It also became an emission control device, by allowing quicker warm-up, which gets the fuel system running a leaner mixture (14.7:1) in a shorter time after start-up. It reduces hydrocarbons and CO in the exhaust during warm-up.

Many of the older cars (1959 Chevy Impala for example) had a valve in the exhaust that restricted flow and forced exhaust through passages in and under the carb to get it warmed up a little faster. However once the valve got warm enough it would open. I am unsure exactly how the superhawk works with the coolant lines (literaly just bought it) but the cars only forced exhaust through there till it was warmed up a little.

I recall hearing that older Kawasaki's use this method, because they had "carb icing" and cold blooded carb issues. Check 1980-1990 kaws.

As VTR surfer said
"the intake manifold was heated with exhaust gas to give better driveability during warm-up and to prevent carburetor icing"

In addition to this: it helped with better atomization of the fuel.

That's true. Commonly called the "heat riser valve". I was controlled by a thermostatic spring, like an automatic choke on a carburetor. When they stuck closed it could cause preignition and burned valves. They weren't used after the '70s. GM used a vacuum controlled heat riser starting in the late '70s I think, called the EFE valve (early fuel evaporation), until they went to EFI in the mid to late '80s.

Not every car has it. A lot do but not every fuel injected car does. My 88 mustang did and it was a free trick to bypass it and make extra power. My 89 cavalier did aswell. My 97 cavalier however didn't have that option. I was gonna have mine removed but after reading here didn't after asking and reading. Its apparantly needed. It would make sense to remove them. Nothing worse than heating the air coming into the motor right.

The VTR has a dual valve thermostat. When the engine is fully warmed up coolant flow to the carbs is shut off. Flow through the carbs resumes only if coolant temp drops below a certain point. Unless the thermostat is defective I wouldn't worry about the system robbing power or causing funky carburetion.

my vtr runs just fine with no coolant going to the carbs.

alright, I learned alot of things I did not know. I found my problem as well. A stuck vacum slider, I hate those long springs. Thanks for
all the input, the thermostat on the VTR is more complex than most I have seen. I would compare it to a 3-way valve , nice.

you could probably cut those springs in half if you drill your slides accord to jet kit instructions, i think. The springs that come with the jet kits are so wimpy you can install them with no drama. Actually, those long springs are no problem if you use a pencil to stabilize the spring while you compress it into the cap recess. then pull the pencil out and carefully release the spring inot the slide as you push the cap down. Just takes a little practice.

No one said it would make it run any different, there just seems to be no good reason to remove them.

You should have seen the dual diaphragm fuel pump on a 1950's Ford. One diaphragm sucked fuel from the tank and pushed it up to the carburetor, the other diaphragm operated the windshield wipers.

I've had no problem with the diaphragm spring...just hold it in with a small screwdriver, line it up, then pull out the screwdriver.

what if ya got those confused? lol hey I ordered the dyno-jet kit and plan on drilling the slides as they indicate,
as for the coolant lines I might try to loop them without the carbs while I make adjustments. It may just help on R/R time, but it won't hurt anything ,right? Is that what we have all come up with? Thanks for the great and fun
discussion from all.

ps. don't borrow from 50's engineering;)

Holy F@#$ !! I just did my dynojet stage 1 jet kit. Let me tell you
I love it.... still have to fine tune but what a difference in rideability
I gotta go ride.... check ya latter

heater/cooler function
 

The lines may have another function and that is too provide additional cooling of the radiator fluid and increase the cooling capacity of the engine coolant system. The evaporation and atomization of the fuel in the carburator helps absorb quite a lot of heat to help cool the bike when it is hot.

My bike has not had the cooling lines on it since I bought it. I did not know they were supposed to be on the bike until I looked at my spare set of carbs. I have ridden it at 35 degrees out for long periods and when it was 104 degrees outside, and have had no adverse effects in either situation.

I had a Kawasaki 454 LTD in the 80's with Kehin carbs that sure could of used the carb warmers. They used to ice up when it was below 40 and would limit the top speed of the bike to about 70 mph, with lots of backfiring. I would have to pull over and let them self thaw for a few minutes. When it was below 32 you couldn't ride without the choke part way on. Below 29 needed full choke just to run. Yes, it was my only transportation for a year.

Nothing worse than scraping frost off your seat, when you were wearing only jeans, shoes, and a lined jean jacket and had a 7 mile ride home.

The hawk definitely doesn't need them but I have not tried it when it was below 32 yet.

Wow, always tons of discussion with these coolant lines. Since you got a lot of "I dont knows" with long stories of old cars, I can give you at least one other side. I blocked my carb coolant lines 6 years ago and ride year round on city & highway in temps as low as single digits and as high as triple digits. In my opinion there is no ill effect. All possible weather combos like 60* rain into mid 20's in the same 24 hour period with no issues. So there is your field test. No coolant going to the carbs day in & day out. bike runs fine. I guess I am missing out on the cooling effect of carbs (ha) but hope the two big radiators do the job.

that reminded me of the old vw bugs where the tire pressure from the spare powered the washer fluid

Yeah and you found out your washer switch diaphram leaked the first time you had a flat tire, and your spare was flat too. I had a '65 bug.

sure would make taking off the carbs a hell of a lot quicker