RC45 - Bugger to start - bugger to fix

[hollo]

and bugger again. I'll throw this open to the forums collective knowledge/advice.....

I'll try and keep it brief . My RC45 is a real bugger to start from cold ( as in it can be touch and go if the battery will not go flat trying ) , when it's warm it's fine , just from stone cold . The previous owner had the same problem and amongst other things changed the cam sensor , coolant sensor ,and the throttle body inlet rubbers . However a new set of plugs seemed to have fixed the problem. Since I've had it , the same cold starting problem has come back , I've had the valve clearances checked ( which were fine ) and the coils changed - as the bike shop it was at last summer were convinced that the sparks were only working on one bank at a time ( hence the new coils ) . However the problem is still there . The only thing I can think of is that either there is an intermittent fault with the CDI, or a problem with a connection in the loom somewhere - In trying to do some research a CDI has never been know to ever fail on the 45 and it will be an expensive thing to replace on a hunch. It's been though two different bike shops with the previous owner and myself . I've contacted Stephen at GT motorcycles who is a Honda V4 specialist , but he's quoting an 11 month wait/leadtime and he also in Plymouth which is a long,long way from me.

I just wondered what other opinions people had , or if anyone has got any experience of any bike shop which they think could help me who are good at diagnosing this kind of problem  . I'm in Maidenhead Berkshire , so ideally wouldn't want to take it to the other end of the Country.

Thanks

Mike 

 

       

[TLRS]

Have you tried hotter plugs? Maybe the spark is too weak. Any idea how well the injectors spray?

[Damnthistinleg]

Possibly look at what senses the conditions/sets the parameters for whatever choke it runs for cold starts?

Will it fire up from cold easily with a cheeky squirt of petrol down the intakes?

[hawkati]

 

[Bram43]

Don’t they all do that? 

It’s all part and parcel of the submissive and dominant relationship that comes with Honda ownership.

Cold starts are common and can put new ownership off balance at first, but it’s not the end of the world.

First thing is to be sure and confident of your place in this relationship. What kind of dom and sub relationship do you have?

Brat taming, is not something that one comes across with owning a Honda. Strongly consider having your eyes checked as you may have purchased a Ducati. 

Degradation and humiliation goes hand in hand with being a dom over your submissive Honda. For the inexperienced dominatrix this might seem a bit harsh and severe but Honda’s thrive on degradation and humiliation. There are literally no words that you cannot use on your Honda that are beyond the pale and never let it or any service adviser fool you into thinking that there is, because there isn’t. It’s a Honda. 
Just be yourself, but dominant. Firm is fair and fair is week, it gives it hope. It’s submissive wants is all the hope it deserves and it is your job to crush that under the high heel of your latex boot. 

Caring dominance, is for the meek and Yamaha owners. Like spaghetti, their frames and Essex girls, they are straight until they’re wet. 

You own a Honda. Therefore you are a dom and not a switch. 

There is of course one exception. This is trick that you can play and play only once…Start out pretending to be a caring dom and then with a swift and brutal withdraw of that caring soft hand, you change your mind and leer over it like the glorious and malicious bastard that you are. 

Remember, you are a degrading and humiliating dom. There’s nothing more degrading then a few choice words to use when the bastard thing won’t start and coughs and wheezes with it’s pathetic attempts at life.
One responds with a tone of contempt and disgust.

“Is that the best that you can do?”

”If you can’t do it right, I’ll find another that can.” 
This is a classic line that will illicit a satisfying whimper of regret that will be felt back in Kumamoto.

Of course the life of a dom and a sub can’t revolve around the same theme day in and day out. 

Maybe the cold start issue could be a breathing problem. Check the airways for a clean smooth flow, choking the fucker is perfectly acceptable, but often it is all to easy for one to over do it and they’ll idle above their station in life. Sometimes less is more. There is no point killing your sub, because then you’ll have to go and buy another one and that’s a pain in the arse. Again, you are not a switch, you’re a dom. Clean injectors and throttle bodies means that you can give it a good spanking, don’t let anything take that pleasure away from you.

If all else fails, check the insurance policy is up to date, your alibi airtight and ensure that the ensuing accident is fun and worthy of the scrapbook. 

Edited February 10, 2023 by Bram43

[Thunderbolt]

I would be going deeper than just the clearances. The clearances may be in spec, but the valves may not be sealing well enough. Or there might be blowby? What sort of compression are you getting? Can you do a leak down test?

Maidenhead isn’t far from Taplow, what do PDQ say?

[EXUPDEL]

6 hours ago, Bram43 said:

Don’t they all do that? 

It’s all part and parcel of the submissive and dominant relationship that comes with Honda ownership.

Cold starts are common and can put new ownership off balance at first, but it’s not the end of the world.

First thing is to be sure and confident of your place in this relationship. What kind of dom and sub relationship do you have?

Brat taming, is not something that one comes across with owning a Honda. Strongly consider having your eyes checked as you may have purchased a Ducati. 

Degradation and humiliation goes hand in hand with being a dom over your submissive Honda. For the inexperienced dominatrix this might seem a bit harsh and severe but Honda’s thrive on degradation and humiliation. There are literally no words that you cannot use on your Honda that are beyond the pale and never let it or any service adviser fool you into thinking that there is, because there isn’t. It’s a Honda. 
Just be yourself, but dominant. Firm is fair and fair is week, it gives it hope. It’s submissive wants is all the hope it deserves and it is your job to crush that under the high heel of your latex boot. 

Caring dominance, is for the meek and Yamaha owners. Like spaghetti and their frames, they are straight until they’re wet. 

You own a Honda. Therefore you are a dom and not a switch. 

There is of course one exception. This is trick that you can play and play only once…Start out pretending to be a caring dom and then with a swift and brutal withdraw of that caring soft hand, you change your mind and leer over it like the glorious and malicious bastard that you are. 

Remember, you are a degrading and humiliating dom. There’s nothing more degrading then a few choice words to use when the bastard thing won’t start and coughs and wheezes with it’s pathetic attempts at life.
One responds with a tone of contempt and disgust.

“Is that the best that you can do?”

”If you can’t do it right, I’ll find another that can.” 
This is a classic line that will illicit a satisfying whimper of regret that will be felt back in Kumamoto.

Of course the life of a dom and a sub can’t revolve around the same theme day in and day out. 

Maybe the cold start issue could be a breathing problem. Check the airways for a clean smooth flow, choking the fucker is perfectly acceptable, but often it is all to easy for one to over do it and they’ll idle above their station in life. Sometimes less is more. There is no point killing your sub, because then you’ll have to go and buy another one and that’s a pain in the arse. Again, you are not a switch, you’re a dom. Clean injectors and throttle bodies means that you can give it a good spanking, don’t let anything take that pleasure away from you.

If all else fails, check the insurance policy is up to date, your alibi airtight and ensure that the ensuing accident is fun and worthy of the scrapbook. 

@Bram43has put way too much thought into this. Makes me feel very nervous about my addiction to shitty hondas from the 90's 

[2moto]

I'd start by doing a leakdown test. That will confirm the state of the engine. Next I would check the spark on all cylinders. Then check fuel delivery.

Has it ever started easily from cold in your ownership? 

[TLRS]

4 hours ago, EXUPDEL said:

@Bram43has put way too much thought into this. Makes me feel very nervous about my addiction to shitty hondas from the 90's 

You're well on your way of being a dom ain't ya. Four Honda's and you call yourself Exupdel.

[bignige]

Yet my RC46 has been faultless.

🙈🙉🙊

[Mr Tea]

Why hasnt @EvilSpike or @Stephenrc45 been called to the RC45wontstart phone yet ?

 

[TLRS]

21 minutes ago, Mr Tea said:

Why hasnt @EvilSpike or @Stephenrc45 been called to the RC45wontstart phone yet ?

 

Our innkeeper @jaycee  must be otherwise engaged

[Thunderbolt]

52 minutes ago, Mr Tea said:

Why hasnt @EvilSpike or @Stephenrc45 been called to the RC45wontstart phone yet ?

 

I think @Stephenrc45 has been consulted, but has an 11 month waiting list.

[EXUPDEL]

2 hours ago, TLRS said:

You're well on your way of being a dom ain't ya. Four Honda's and you call yourself Exupdel.

my first decent bike was a brand new thunderace in 97. my first email address in 2000 and what ever was Exupdel@....

[hollo]

7 hours ago, 2moto said:

I'd start by doing a leakdown test. That will confirm the state of the engine. Next I would check the spark on all cylinders. Then check fuel delivery.

Has it ever started easily from cold in your ownership? 

I'd need a help ( as in taking it to a bike shop ) to do a leakdown test , as at best I'm a spaz wen it comes to most mechanical things .  The engine must be fairly healthy as with a power commander fitted it gave 122hp which aint too bad for a almost 30 year old 750. The bike shop I left it with last summer checked the fuel pump and that's at the correct pressure , but they were convinced the sparks were only coming from one bank of cylinders at a time . A new set of plugs did solve the cold starting issue , it was as good as gold , but it's now slipped back into being a sod.  

[426hemi]

9 minutes ago, hollo said:

I'd need a help ( as in taking it to a bike shop ) to do a leakdown test , as at best I'm a spaz wen it comes to most mechanical things .  The engine must be fairly healthy as with a power commander fitted it gave 122hp which aint too bad for a almost 30 year old 750. The bike shop I left it with last summer checked the fuel pump and that's at the correct pressure , but they were convinced the sparks were only coming from one bank of cylinders at a time . A new set of plugs did solve the cold starting issue , it was as good as gold , but it's now slipped back into being a sod.  

Have you tried another set of plugs, my gixxer 1100 would start fine on new plugs if you rode it and got it hot, if you did a few starts and stops it would foul the plugs and not start unless you cleaned or fitted new plugs, bsd went through the carbs and spent quite a bit of time setting them all up.

[Alpinestarhero]

24 minutes ago, hollo said:

I'd need a help ( as in taking it to a bike shop ) to do a leakdown test , as at best I'm a spaz wen it comes to most mechanical things .  The engine must be fairly healthy as with a power commander fitted it gave 122hp which aint too bad for a almost 30 year old 750. The bike shop I left it with last summer checked the fuel pump and that's at the correct pressure , but they were convinced the sparks were only coming from one bank of cylinders at a time . A new set of plugs did solve the cold starting issue , it was as good as gold , but it's now slipped back into being a sod.  

Is the power commander still on it...?

[EvilSpike]

I don't have a choke/fast idle lever connected on my bike, and it starts merrily after a couple of stabs at the button even after six months sat idle.

My guess, and having been down this route before would be fuel pump and injectors, or the PC-V.

Last time I had running issues my fuel pump was making the required pressure, and flow. If you bridge the fuel relay and power the bike on, the pump should push out of the return feed pipe 220ml at least in 10s. Mine was making way more than that.

But, changing the fuel pump and filter then ultrasonically cleaning the injectors has completely solved the problem and the bike is running beautifully again.

My advice would be to do that, new Walbro pump will cost £70, £10 for a Ducati filter that pops right in and injector cleaning around the same.

Work from there, but ultimately that pump is close to 30 years old and the simplest item to fail.

[marvin]

5 hours ago, bignige said:

Yet my RC46 has been faultless.

🙈🙉🙊

That’s because it’s 1 betterer 

[Jenny Pryde]

If there is a cable-operated fast idle, I'd check the routing and that the cable is moving as it should.

[Tumz]

1 hour ago, marvin said:

That’s because it’s 1 betterer 

so, I'll expect a lot of problems when I'll attempt to start Maddie around March 1st....

[EvilSpike]

1 hour ago, Jenny Pryde said:

If there is a cable-operated fast idle, I'd check the routing and that the cable is moving as it should.

My RC45 has never had an operating fast idle in my possession, not has it ever struggled to cold start outside of having fuel pump and injector issues.

Hollos problem is, I believe entirely separate to the fast idle.

I also have never known anyone to use a PC-V successfully with an RC45, but my experience is very limited outside my bike and whatever Steve has told me.

[2moto]

If new plugs solved the problem before, I would try that again. Cheap and easy test. If it works again, that will narrow it down considerably.

[bignige]

Might be worth going to Iridium 

[hollo]

3 hours ago, 2moto said:

If new plugs solved the problem before, I would try that again. Cheap and easy test. If it works again, that will narrow it down considerably.

Thanks for the suggested help so far . I don't think it fuel pressure issue as it tested out OK , and when it's trying to start it can pop and bang which says to me fuel is getting though. 

This may sound stupid a question, but if I fit new plugs and and it goes back to starting OK , I'm back to square one  , with the finger being pointed at somehow a lack of, or weak spark ? .

[TLRS]

It would certainly help find direction. New plugs are clean and should provide a good spark. After running the bike for a bit, a cold plug could foul up. Which, afaik, reduces spark.

Do you know what plugs are in the bike? And do you have a manual that suggest a specific type, or maybe different types depending on the use of the bike (road or track)..

[Thunderbolt]

7 hours ago, hollo said:

Thanks for the suggested help so far . I don't think it fuel pressure issue as it tested out OK , and when it's trying to start it can pop and bang which says to me fuel is getting though. 

This may sound stupid a question, but if I fit new plugs and and it goes back to starting OK , I'm back to square one  , with the finger being pointed at somehow a lack of, or weak spark ? .

Or you could put new plugs in and it masks the underlying issue for a while.

Pop and bang, suggests fuelling, when we’re the injectors out last? An ultrasonic clean may be all that is needed.

Delving deeper, you are looking at fuel  filter and pressure, then what does the cold start map look like?

[CMSMJ1]

Plugs are a workaround. 

You need a root cause.

They are simple things in the end aren't they? 

Injector cleaning a good idea anyways so I'd be into that and a pump as per the Spike!  

[hollo]

Thanks for the suggestions . The plugs in it are as per the manual ( CR9EHIX-9 , I think ? )as it previously had much shorter in length racing plugs in it. The thought was that when they were changed to standard plugs and fixed it the starting issue first time , as the racing plugs were shorter and designed for sustained high revs the spark was not sparking in the ideal place for cold starting and normal road riding.

The previous owner had the injectors cleaned when new seals were fitted , and this must of been less than 1000 miles ago , which is why I'm leaning towards the spark, or lack off possible cause. As I said at the beginning once it warmed up it starts on the button which in my mind just adds to the confusion , as it's not a constant problem .

[2moto]

OK, here is an idea. Replace the coolant temperature sensor with a resistor with the value of a warm engine. That would tell you whether it has something to do with the ECUs cold start function.