How to fix a motorcycle that overheats in slow traffic
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- Опубліковано 17 тра 2024
- This video describes how to diagnose a motorcycle that overheats when it idles in traffic. This specific problem is often a consequence of a problem in the cooling fan circuit for water cooled bikes and cars. The case study described was in a 1995 VN800A Kawasaki Vulcan.
The video describes an approach to diagnosis that uses minimal tools, and stands a high chance of proving the diagnosis before buying replacement parts.
Auto repair is inherently dangerous, both from the perspective of personal safety and risk to the vehicle itself. This amateur video is published for entertainment purposes, and is not guaranteed to be complete or accurate. It is published in good faith, for free, but with no guarantee.
While researching a problem with your bike, always seek out at least two sources for critical information and bear in mind that any step into the home repair field carries risk. If you decide to accept the risk of DIY repair, any misadventure you encounter is on you. - Авто та транспорт
These old bikes are a nostalgic glimpse back in history, although there are millions still on the road. By integrating a bimetal switch into the sensor, you route the full power going to the fan through the sensor. It's an elegantly simple solution, but the contacts take a beating from inductive voltage spikes, arcing, heat from big current flow, big swings in temp and the chance of corrosion from leaking coolant through seals. On the positive side, when you include both the afferent and the efferent loops of the decision tree into one tiny sensor, you don't need a computer to make decisions. Newer bikes use a thermistor that sends data to the computer, which then commands a MOSFET driven efferent arm to power the fan independently. By giving the computer data like coolant temp you can delete the choke and carb, and use that temp data to adjust fuel trim, etc. Even though old bikes have their failures, I doubt many computer controlled bikes will approach 3 decades of survival.
Great diagnostic Dave and using a simple jumper is the fastest way to check the entire circuit. Great follow-up for folks to prove that the fan switch was bad in a boiling pot of water. Take care and have a great day!
damn, wish i still had my 98 vulcan. followed a few of your videos to fix some other things on it, thank you for that. my radiator fan also stopped working. it was good excuse to ride the shoulder in traffic lol
Great to see you back with another video as a fellow 99 Vulcan owner myself with the classic model. I'm a little crazy with maintenance but I always change my radiator fluid every year and suck out the overflow bucket, I noticed these sensors fail due to inadequate maintenance sometimes.
Excellent point about the overflow reservoir. I skipped over it this time, but I could still do it now. It's been almost two years since the last cooling system flush when I did the video on that leaking coolant pipe.
Great video. Always love your content. Especially your knowledge on 2nd gen Dodge Ram pick up trucks. Keep em coming. Thanks
I still own my '99 Kawasaki Vulcan 800 classic and bought it new and it is in showroom condition, still to this day 25 years. Just repainted the tank and the fender.
Here in BC we have a 'classic vehicle' designation, that reduces insurance expense by 75%. I managed to get this bike into the program. They are very picky about not having any modifications, and even a tiny seat tear would disqualify.
I do like the Vulcan Our friend Johnny Pilot the blues player has one. I helped him with a carb problem on it some time ago.. Sail Safe mate. Ant & Cid
You create great videos. In an environment where here in the U.S. we too often have trouble sourcing parts for vehicles 15 years old I am impressed that you seemed to have no problem sourcing a part for your nearly 30 year old motorcycle.
Yes, good point! There's still a healthy aftermarket for these classic sensors, but the lesson regarding newer computerized vehicles is a daily headache. Manufacturers evidently care more about getting rid of competition (old cars) than they do about their reputation.
Top notice video. I don't even have a motorcycle anymore and you still made it very interesting. Thank you
What a kind remark, thank you.
Thank you sir, learned a lot
As always I appreciate your thoroughness and knowledge. On newer vehicles always have to be careful jumping wires properly to avoid shorting the PCM. An errant mechanic destroyed my friend's truck PCM while trying to diagnose a fuel pump issue by jumping the signal circuit rather than the load circuit on the relay. Cheers!
The one regret I've been having about this video is I didn't add a clip explaining that very point. So, I'm so glad you brought it up for emphasis in the discussion! Effectively what we're doing here is bypassing only the switch, with the fuse and load still in series. Everything else in the line is designed to tolerate full power coming from the battery. So, it's OK to do here. Beginners have a way of extrapolating, so they need to think this through to understand when it would not be safe. I would never do this without seeing the wiring diagram. Thank you!
great fix , My Honda did the same .. It was a good vid !
Good point Shawn! This presentation of cooling fan failure in slow traffic is easy to recognize after you see it a few times.
amazing
My 99 vulcan classic had the issue of too low coolant causing it to boil and not toggling the lights. Simple fix was to just replace coolant in engine and coolant expansion tank
I've seen that before, too. In a video from about 10 years ago I replaced the coolant hose flange on a VW Jetta, and the adjacent coolant sensor was reading hot. In retrospect the trapped air was superheated, giving spurious readings that completely resolved after fixing the leak and burping the system. In the DIY setting it makes sense to fix what is obvious first, and then reassess. Burping is pretty easy in these bikes but if you skip over that step in some vehicles you can destroy the engine. Air is so compressible that water pumps lose efficiency, especially if the leak is on the intake side where you get cavitation as well. In this case there was no leak in my Vulcan.
My first thought is thermostat.
They go bad so often on all vehicles it's like a joke.
This looks like an electronic version of a thermostat. The old ones in cars were mechanical that impeded fluid flow. The computer thermiresistors have 3 prongs.
The trick is to do this without draining out the radiator fluid.
Those are good points. As you point out, much of diagnostic work is pattern recognition, which helps those with experience to jump to the most likely possibility first. Along that line, the soft overheat while stopped in heavy traffic is very commonly linked to a failed fan circuit. This bike also has an old style mechanical thermostat, the tip of which you can see just under the radiator cap. In my experience those overheats from a failed thermostat are much more violent and dramatic, usually presenting under load at higher rpm. Typically the partially stuck closed thermostat causes a constriction in the fluid pathway, amplified when the mechanically driven water pump turns faster to push out a higher volume of fluid. Then fluid boils over and the cap releases pressure in cloud of steam.
Have followed you for some time now. Enjoy and learn from your video's.
Is it possible for you to make a lengthy or 2-3 part video on 2 stroke outboard engines (5 - 10 hp range). I have just purchased a small outboard for my sailboat dinghy. I'm looking for care and maintenance for the motor. Hope you will consider this.
Thank you from Gibralter.
That's kind of you to say that. Whenever I make a video I survey what's out there already, then ask the question whether what I'm doing is in any way raising the 'bar'. The small engine videos coming out now from various pro shops are excellent, and I don't have a lot to contribute that isn't already there. If I come across a problem in a small engine that might pass the test I'll give it a go. Cheers!
we want to invite you to review the latest taillight for your 00-06 chevy Tahoe Suburban, how to contact you?
They were set to run lean..thus run hit… turn mixture screw out to 3.5 turns out …it,ll run much better and cooler.
Please Dave... My speedometer doesnt work anymore.. i am going to the shop tomorrow too see what the hell is going on.. If i unscrew the cable in both ends and turn it, it moves correctly, but if i put it back in the rear wheel and leave it off at the top and then pushing the bike for a few feet, the cable does not turn around at the top, so the shop thinks its about the gear in the rear wheel... is it easy to fix or what? I really miss a video of how to fix problems like this.. i have seen your speedo cable video, but since i think my cable is fine, i still have a problem.. and my speedo doesnt work at all atm.. went for a short ride today and NO numbers moved on the speedo, not the pin to see how fast i am going, its just at 0 mph, and the miles ridin in total is just standing still, so atm it doenst registre any miles, which is also very bad... what to do?
Cheers from Denmark!
That's not a problem I've experienced. On the distal end of the cable is a fork, which meshes with matching gears internally. My cable was actually broken, which as you say would be an easy fix. If the mating screw connection seems fine and the distal end fails to spin when you rotate the rear wheel, you'll have to disassemble the hub to see what's wrong. Please stop by to leave any feedback that others who visit here might appreciate.
Sorry to hijack the video but I crew on a j/109 and we’ve just dismasted☹️. I’m wondering if you have any knowledge of what a new 109 mast will set us back. Many Thanks:)
Oh my, I'm so sorry. I don't know anything about prices for that. Mine is aluminum, newer boats have carbon fiber masts for better strength and less weight up high. J boats moved to France so new products may come with duties, though I suppose you could find somebody local to do it at home. Here in Canada we pay 25% duty for new boats coming from France. Mine was made in the US so it crossed the Canadian border duty free.
@@spelunkerdthanks so much for your reply. Luckily, insurance have unexpectedly decided not to be difficult and a new mast has been sourced. I’m based in Dublin so no custom duties luckily😄🙏 Find your videos extremely helpful so thank you again!
You missed one part of your initial diagnosis. You should know your bike, you know what it feels like when it gets hot and you know when you're in traffic, the radiator fan should be running periodically.
When that didn't click in your brain, that means there's a flaw in your mechanical diagnostic loop that's not always running. Just like on the sailboat, you're always listening for that rhythmic chug of the water muffler.
As a fellow sailor, I know exactly what you mean. The rhythmic cadence of the salt water pump is so characteristic you immediately sense something is wrong when it changes. The same goes for many aspects of motorcycle use, and indeed the whole philosophy of Zen and the Art of Motorcycle Maintenance comes to mind. I have trouble hearing the radiator fan over the rumble of my V twin, but I bet many bikers are observant enough to recognize that, too.