RC45 Almost Fixed! Not my Finest Work, a Sticking Plaster Solution at Best.

[@carleddison7479]

Can you imagine the discussions between Jim and Allen Millyard? Absolutely no one would know what they would be talking about, but the results would be magnificent!

[@SuperbikeSurgeryTV]

I don't have heroes, but Allen Millyard! F.....me what a legend.

[@throttle-up]

Put a little prox switch on the choke lever to bring in the start resistance

[@Cromwell648]

Don't be ridiculous, Jim hasn't a fkn clue about what he's talking about.

[@Cromwell648]

Don't be ridiculous Jim doesn't have a fkn clue about what he's talking about..

[@diyhell8712]

I like that idea ​@@throttle-up

[@dbx3197]

Jim, really interesting. I’m guessing the engine temp sensor is an NTC (negative temperature coefficient thermistor) which starts high resistance at low temp and the resistance drops as the temp rises. I would expect that you can get sensors with different slopes so that you can have the high resistance you need at cold but drop to a resistance level low enough to hit your injector pulse width target at running temp. Alternatively, you could swap the fixed resistor in the loom for an NTC which would switch to low resistance as the bike warms up. Just a thought but top diagnostics as always!

[@mickleblade]

You beat me to it!

[@llewvirtue861]

Would not another ecu have fixed this

[@llewvirtue861]

Loved this

[@kev.c.j.]

Fair play Jim! Auto Electrics are like herding wild cats so I duft my hat to you sir. I totally get why its taken such an in-depth and serious amount of time to understand, figure it out and find a solution. 👏

[@tonywylde8211]

Not an electronics guy? You could have fooled me! Brilliant work.

[@SuperbikeSurgeryTV]

Kind words, thank you 🙏

[@iantribe1166]

What an absolutely brilliant piece of diagnostic work Jim👏🏻👏🏻

[@seanmoore8152]

"Get to the point Jim" ha. This is my favourite you tube channel. You sir are really good at what you do.

[@sjreidkiwi]

Would make a great t-shirt!

[@smoore5540]

Just watched the 4 parts back to back, really interesting dia and fix, nice one 👍🏴󠁧󠁢󠁳󠁣󠁴󠁿

[@rafaellastracom6411]

Your customers don´t know how good they have it. Outstanding stuff.

[@Alextheampguy]

I thought it was a unusual solution that the temperature sensor uses a 5 volt reference, the cars i usually work on (vintage volvos) use the sensor as a ground reference only , so i learned something new today 👍

[@stephenwilliams6939]

Awesome work one in a million for finding that fault and rectifying it without a new ecu

[@waynep4256]

You, Sir, are amazing. Well done. I've really enjoyed watching and almost felt like I was in the workshop with you. If I had a quarter of your knowledge, I would be a happy man.👍👌

[@usefulcontent9894]

already got a manual choke might as well add a cold start switch, just want to get it going and not mess up warm running. have a light to remind it is on cold or hot running.

[@jackjones8552]

Loving the weekly uploads, hope the channel stats are reflecting the effort you are putting in

[@ianbates1312]

Jim you want a medal the size of a frying pan for your patience on fettling this nightmare problem 🙏🙏

[@ragnarironspear1791]

No notification Jim today , but brilliant as always. Ive been building bikes and fixing them for 35 years and i still learn new things watching you 👍🏻👍🏻

[@grahamhill9770]

Top job on that one... I would be more than happy with that result as a customer. I really enjoyed this full on techy investigation... Followed you all the way. Before you mentioned my thoughts were a cold start resistor switch array, but you got with a single resistor on its own. Hat off to you fella a top effort indeed.

[@cabbage681]

That's a very clever sticking plaster 👍

[@roonewby8112]

bit of a head mangle for me a mere mortal but Ive learned loads and found it really interesting. Well done mate ,that was a proper head scratcher! I admire your logical disection of the problem and can appreciate you can only do so much in a certain time frame. Top result, keep them coming your vids are so watchable and hugely interesting.

[@philiphiggins4822]

Your very clever jim, waffling isn't a n issue. Your just describing what your doin as you go along. Vids are great Your stuff came up on my youtube and ive been working my way through them. Likes left on them and subscribed mate

[@zweispurmopped]

May I suggest you put a pot and a resistor in series? The fixed resistor with a value to match the low end of the resistance required an the pot with the full-on resistance to take it past the high resistance value? That probably would be the easiest way to cheat the ECU into working.

[@GaryInch-e7p]

Fantastic Fix, I'd be delighted with that progress...... cold start switch is a great solution, great channel, by the way.....

[@bigstevemex]

Hi Jim Love your videos,keep waffling,we all learn things from it.why not see if you can find a variable resistor to wire into the plug you’ve fitted,you might even be able to fine tune it while it’s running.I remember doing something similar many years ago on rover turbo to trick the ecu into providing higher fuel pressure and boost. Obviously you can imagine the eventual result😂😂 Steve

[@Busaboy1300]

Wow.your knowledge is unreal.i must admit,I do listen to every little waffle you do.brilliant video Jim.

[@laurencehastings7473]

Brilliant Jim. I'm as thick as a plank, don't know sod all about electronics but still understood the nature of the problem, the diagnosis, the remedy and how you got to the optimal resistance value. I personally think that the switched solution would be the most practical, similar to the good old choke lever from days of old, when knights were bold and electroics weren't invented. You choked your horse with no remorse until it hypervented.

[@999fugazi]

Above and beyond. Amazing work Jim and thanks for filming this journey

[@lewiscollins1045]

I had the same problem on a SP1, I just bypassed the loom and wired the temp sensor straight to the ecu, job done. Everything about that RC45 smacks of ex race bike.

[@mikecharlick8119]

Incredible work and problem solving! Good to watch and learn from an expert. Thanks Jim

[@notsohairybiker]

Jim, It's the best fix because it works.

[@malcolmnash5850]

Absolutely Brilliant all 4 episodes.

[@daveclucas8738]

Total class and the stuborn determination to get this brain scramble sorted is ace. Love your content mate

[@CRBN74]

Brilliant! I wish I could have you around. Learned so much from you!

[@BigBadLoneWolf]

Keep waffling Jim, it's a great insight into the thought process of diagnosing a problem

[@iancharlesworth3654]

You are the BOY Jim. Well done you. Very interesting. THANKYOU. 👍👍👍

[@derekm6236]

Brilliant worked and freely shared with us all. I wonder how few mechanics are capable of diagnosis and fix like this???

[@corysmitheram8846]

Hey. Love your videos. Old power commanders use to manipulate sensors signals to trim the injector duty cycles according to the map programmed into them. This was before they started intercepting the actual injector pulse. One of those sensors was the temp sensor. Perhaps this bike use to have and older power commander which could explain why the wire had been previously cut.

[@ianmurray3820]

Fascinating video Jim, I’ve watched all of them and wondered what the combined resistance of the air temp sensor/ water temp sensor were, and whether the ECU. Measured both on the cold start, - only because water sensor was in range and the ecu needed such a massive rise in resistance before it kicked more fuel in.!!.????? Just a thought..!!!👍

[@ohboy2118]

This is only my opinion but if you have to pull the choke then flicking a coldstart switch would be my preferred solution so that you aren't potentially changing the hotstart/running performance. Jim, I loved the cause /effect diags. Please stop apologising for yourself. I like the talk outloud (waffle as you call it) because it helps me understand your thought process and gives me an insight into all the years of experience you have locked away in your brain. You are who you are and no apology is required!👍

[@SuperbikeSurgeryTV]

Thanks for the kind words 🙏

[@Idoall.myownstunts]

Why does a choke exist on this bike if it's injected?

[@SuperbikeSurgeryTV]

​@@Idoall.myownstuntsTechnically not a choke in the true sense of the word. Just a fast idle. 👍

[@ThomasMoore.1]

Great series of videos Jim Always learn something watching your videos 👍

[@nods-p6c]

Honda use a proprietary protocol for their ECU's which communicates over K line at a baud rate of 10,400. PGM-FI supports 77 parameters and can be read using a J2534 interface. As i an sure you know there are many factors that control injection pulse width on the RC45. Reading and logging the live data would be my suggested method to really get to the root cause of this problem...Good luck!

[@stuartswaby777]

Weldone rc45 watched time after time Proper old school diognostic welcome Jim recards Stu👍

[@vladoovg]

The ECU likely has old and dried-out capacitors. You can add three-position micro switch to the choke mechanism.

[@basilwatson1]

this is cropping up a lot me thinks its how to remove that potting Ive tried the boiling water trick no luck !

[@julianwilson5468]

Yep, best explanation I can think of. Lucky it hasn't failed, but I suspect it's on its way to failure.

[@travismoan6168]

Those mirror bolts, and the screen bolts are driving my OCD crazy. Top job on the cold start fix Jim.

[@jimallen199]

Cheers Jim very interesting series I think you would one very few who could have found a work around for this. Most would have said it need s a new ECU, if they were able to figure that much out.

[@Bunter1815]

Loving your work. Just a tip, when graphing it's normal to put the thing you're controlling (in your case ohms) along the horizontal and the thing you're measuring (pulse width) on the vertical.

[@drmark5526]

Beautiful solution Jim. I don't know tiddlywinks about the electronics, but I know a brilliant fix when I see one. Keep up the waffaling 😜 Mark

[@PhilFoster-z7m]

Thanks for the vid Jim, great patience and tenacity. I had a similar prob with a Honda CRV car (same sort of PGMFI set up) The internal ground path in the ECU for the ECT was out of spec. This also affected other components like the MAP sensor and idle speed control valve. Once these ECU's have an issue, replacement is the only real, but expensive, cure. Loved your fix. A bodge is only a bodge when it fails don't they say!

[@peripheral1258]

Magnificent perseverance with the link between engine temperature and how the thermostat determines fuel pulse width and rich or lean... I hope to find a mechanic like you before I actually need one. Wait. Wait!! How about taking us for a test ride on an obvious example of a really cool bike... that needs a good spanking test blaaat !! ps: I don't know a fart about this stuff but likes what that dbx guy said...

[@brian623]

You are such a clever person. I love taking things apart and putting them back together which I’m more than capable of doing but understanding what you’re telling me doesn’t mean the thing.😊

[@Northfox46]

Driving my OCD mad looking at the over length bolts & incorrect bolt type all over that bike! As always Jim spot on 👌

[@derrickmanning2597]

Hi Jim,it's not waffle buddy it's information! I jumped in about 2 seconds before you and said slap a resistor in the lead,to alter the cold end. No idea how I came to it unless I paid attention! I do RC trucks and have to do silly stuff to make things how I want them on electronics,still learning but enjoy your methods mate,cracking bike and even better tech!

[@julianpalmer4674]

Jim I think the temp sensor is out of tolerence, have a look at NTC thermisters, at 25 degrees 5K increasing to 10K at 10 degrees and dropping to 460ohms at 100 degrees.

[@vincenttill8051]

Exactly, this is what I would do and just machine a brass insert for the rad to pot the thermistor in

[@SuperbikeSurgeryTV]

That's interesting 🤔

[@graemerichmond1425]

Agree…use an NTC epoxied to the radiator

[@motorbikesandhacks]

Fantastic investigation and a neat "hack" to work around a complex problem! Inspirational, educational and awesome.

[@stevenhoward8792]

Hi Jim, brilliant video and very informative, I love your explanations and visual content, your knowledge is second to none and your videos in general are very interesting and informative, I'm quite nieve about electronics contained within the workings of a motorbike engine, I watch your videos for enjoyment, entertainment and about all gaining some basic knowledge, great job Jim.

[@AlfOfAllTrades]

Excellent info, excellent "waffling", and a great result. Very interesting conclusion to a weird issue.

[@samh3145]

Excellent diagnosis, what a journey

[@mickl8212]

So on an ECU, you've basically done a fuel temperature injector offset correction to attain the correct amount fuelling by adding that resistor.

[@markaddy53]

great work as always lad looks like youve sorted it well done next video please

[@TheDervMan]

Jim, you're brilliant. Loved the video, loved the troubleshooting and loved the faffage. Thanks for sharing your knowledge.

[@estrikadev9554]

Find the sweet ohms resistance that makes it start cold, grab a switch and connect the resistor to it to temp sensor, when you need to start it just switch it, when hot cut switch for normal temps

[@malcolmdobson1244]

spot on...keep it going..say what you think.

[@alepaz1099]

"Get your thoughts together before you open your mouth" that's sound advice 👍 i think that putting a switch to connect the extra resistor on/off would be a better hack (there seems to be something going on on the ECU) 🤷‍♂

[@211tweed]

What chance does an old bugger with limited electronic knowledge have in his wee garage. I just hope my Aprilia Tuono V4 Factory only needs basic mechanical work in the future, or I am in for a long drive down south. Love the content. Signed up to Patrion for the first time as your videos are the most interesting to me on KZbin.

[@dalemeadows225]

Loved this series, good job Jim 🫡

[@davidashton9580]

Well done Jim, nice one 👍

[@stevepacitti9206]

You've excelled yourself Jim! What a great series of videos. And I've learned something about fuel injection systems and how ECU's and associated components modulate engine performance. Thanks very much for taking the time to expain your thought process during your diagnosis, fascinating stuff.

[@BuZZarDFPV]

in case you didn't know, you can boil potted electronics to soften the epoxy to a point it peels out like rubber.

[@devious17]

Well Done, Jim!

[@Preparedprojects]

Really enjoyed this little series Jim..fascinating to watch the diagnosis and hats off to you. I understood perfectly what you were saying although I do have some electronics background to be fair, but even if I hadn’t, I think you did a great job of explaining the issue and the fix mate..well done 😀👏🏼👍

[@steenlassen5718]

Some temp sensors have two readings: One for the gauge, and one for the ECU/CDI. They have two pins on top. One might read OK, like the gauge, but the other is totally out of wack! Maybe because someone dropped it! Bonus: car temp sensors are about 1/4 priced. And exactly the same. Usually a Suzuki car thinghy does the trick!

[@malccolliver4721]

Jim that was the bollocks top job. 👍👍👍👍

[@kevowski]

Amazing skills used to identify/ rectify the issue. Thoroughly entertaining to watch, thank you for sharing 👍🏻

[@stevenmcc6052]

Rather than manual cold start ... you can buy timed relay. So wire in your 5k in series with 3k sensor. Wire the timed relay across 5k res. Relay shorts out 5k after sa1.5mins. Shimples. Schneider electric do good one. Does that make sense 😮

[@darcylandry4669]

Well done Jim! I really enjoyed this series of videos.

[@hsg288]

Well explained , great fault finding .

[@eliotmansfield]

would it not be easier to fit a 5k 15 turn pot in series and then adjusting for the sweet spot?

[@johnmoylan7202]

Brilliant outcome, very well done very educational to me. Also a great introduction for me to the value of an oscilloscope an.d what it can tell you

[@martinatkinson7893]

That has fried my brain Jim!😂 Brilliat work though!👍

[@SB-vb8ch]

The 5v ref is via a pull up within the ecu, it's a potential divder circuit... Looks like thesensor has gone squiffy (not unusual), you have high resistance through the harness (the fact you have a chopped harness is suspect) or there is something awry with the ecu itself. That would most likely be a dry joint which means the pull up resitance is higher than it should be (like i said before the voltage is what it is measuring rather than resistance). Extra injection PW during cranking is totally normal, you'll have enrichment due to temp but alsodue to very low airspeed during cranking which causes fuel dropout. Some setups actually do a short priming pulse on initial power up too in an attempt to wet the ports before cranking.

[@TheMostDangerousWayPossible]

Absolutely brilliant Jim!

[@darylnicklen3685]

Jim this had you on the hop can you in next video just mention if you left resistor connected or made a cold start switch. It's hard with early electronic systems if you can no longer source good replacement parts. As long as it runs close to spec is the most we can ask some times. Job Well Done.

[@danharbun483]

I would think he has left it with that resistor in so the customer doesn't have to mess with it. The take I took form it is that cold start needs about 5000 ohms the full choke is about 3000ohm with then makes his resistor 2000ohms.then when it's warmed up it just needs 2000ohms to run smoothly. Something like that😂😂😂

[@Bunter1815]

​@@darylnicklen3685 my money would be a cold start switch, I can't see a permanently wired resistor able to simultaneously cope with the coldest start resistive requirement and normal running. If you watch the video the 2.5 k Ohm and 3 k Ohm hot starting is wooly compared to without and that doesn't get the resistance high enough for a cold cold start.

[@nickrider5220]

Great work, understood everything and was a good watch - thanks Jim 🍻

[@Sgaphotographic]

Just put a two way on(3 pin) switch in, one that's direct for when it's warm and the other with a resistor for when it's cold

[@koolopscsm3695]

Yes once you determine the switching value add a PLL circuit.. Done

[@nicholastaylor1546]

Awesome series thank you

[@carlhansen8668]

Great video, I love these videos every Friday 😀

[@PurpleripplerTTV]

Been binging your old videos waiting for a new one haha.

[@MrDuhfactor]

Wow..... unreal..... well done man.....

[@derbyjohn972]

Not a clue what you were talking about Jim 😂. But you are a legend and love a waffle mate 👍🏻

[@peterturnbull9133]

Firstly really enjoying your videos. As an FYI I found a cheap ( about £6) configurable voltage switched relay on Ali express. This can be activated in various configurations with high , low or both voltage thresholds. I this you could use something like that to automatically switch your resistor in and out using the output from the temp sensor ?

[@rc2634]

Thanks for the learning lesson

[@paulwatts905]

👍 well done. oh the lovely v4 sound 👍👍

[@Sirloincloth1st]

Brilliant job.

[@ReCheck_WotTheFluck]

Great vids, the waffling is great. It's like doing maths showing the working out aswell. If it is the same water temp sensor that shows temp on gauge, then it must be fine otherwise it wouldn't show correct temp. 👍

[@ReCheck_WotTheFluck]

Lee johnston's RC45 is MINT that he's just done a yr ago. Videos are " Riding the classic TT? " and " The news is out!!! " . Better put this one up aswell " Up close. Lee Johnston's Honda RVF750 RC45 race bike. Manx Grand Prix special. "

[@charade993]

Good work! It doesnt make sense why you have to restart to see the change take effect. How on earth does the warm up enrichment work during running? It would just run 'cold' until the next 'hot' restart. As apposed to gradually remove additional fuel until normal temp.

[@smd-tech]

How about 2 coolant sensors in series? Double the signal range.

[@stevenmcc6052]

Could use central heating thermistor. Eg vokera one. About 9k cold and 900ohms hot

[@richardtaylor3086]

Way over my head Jim but still enjoyed it 👍

[@yodinator]

More epic wafflage Jim, keep em coming! 😜

[@michaelgemiouk]

Clever boy like your work genius really inspired 😊

[@LasseJOugaard]

What a weird and troublesome problem. Some component must be broken inside the ECU, but that thing is next to impossible to repair when it's potted. I assume another ECU for one of these are complete unobtainium? Here's a thought: If you cannot find another sensor with enough range, you could simply run two coolant temp sensors in series. Find a pipe somewhere with enough space to weld on a boss. Get another coolant sensor just like it and wire them in series. That would give you about 6.000ohms when cold and about 500ohms at running temperature. Should be plenty to get over "the hump" when cold, but low enough to prevent any enrichment when running.

[@richardballinger517]

From your description of the 5V feed to the sensor, sounds like the sensor forms part of a potential divider to the ecu input. Posibly a duff amp so loss of gain/voltage to the brain. By adding more resistance to the sensor you increase the voltage seen by your ecu so you'r on the right direction if its what I think the problem might be. Shame it was potted. Could soak it in acetone for a long time and pour the potting off but a pain in the arse. There are no shorts/leakage path on sensor return wire pulling the voltage down?