Popping with choke on - Any cause for concern?

[Tempest]

Just giving my VTR a few static warm ups now there's life again
Also accepting that, a good run would be in order also, (if was road legal then that's what I'd do)

However, just noticing something that was happening yesterday, and today, so thought I'd ask here for your thoughts.
When starting from cold, I pull the choke out, fires up instantly, revs higher than normal tick-over obviously, but every 10 seconds perhaps (not timed it exactly and it's a bit random) I get the odd Pop, Bang (Misfire? Carb fart?) Basically a short sharp pop/bang out of the exhausts.

I was thinking I may try a recording for you, but not done that yet.

If I take the choke off (and it's not really needed much in this weather anyway) these random pops seem to stop totally, if I them pull the choke back out again, the revs go back to around 2000 rpm and I get the pops again.

Might there be any real reason for this?

Just to note: when I finally did get the carbs back on the bike, and fired it up for the 1st time without any air box on, so I could see the ends of the cards exposed, back then, I did see the occasional, what I guess one could call, flashback in the mouth of the carb, just every now and again, but likewise, thinking back, this may also have been with the choke on.

Thoughts?

[RickTheHuman]

Its not going to run smoothly with the choke on, especially when warm. It's probably just unburnt fuel igniting in the hot muffler (blowing carrots is the technical term ) Choke is only used for cold starting. If it's running good normally, I would leave it at that.

[Steve97]

Its not going to run smoothly with the choke on, especially when warm. It's probably just unburnt fuel igniting in the hot muffler (blowing carrots is the technical term ) Choke is only used for cold starting. If it's running good normally, I would leave it at that.

That, Rick, is very good, have you ever considered a career in the diplomatic service

[RickTheHuman]

That, Rick, is very good, have you ever considered a career in the diplomatic service

Cant say I have Steve. Although it sounds like a fun job

[8541Hawk]

The popping is easy.... you have a rich condition, which is common as you have an enriching circuit not a choke on these carbs.

I will say I hope you are not letting the bike sit on the side stand and idle while doing all these "warm ups".
This is the worst thing you can do to your VTR.

If you absolutely need to warm up the bike, then use a paddock stand or sit on the bike.

The whole sit and warm the bike up is not necessary. Nowhere in the owners manual does it say let the bike sit and warm up.
While some might not agree or believe you will damage your engine if you don't do a through warm up, this is just not true

On my bike, I have never let it "warm up" for more than 30-45 sec before setting off.
Yes you keep the revs down (for me that means below 5K) until the temp gauge starts moving but that is all that is needed.

As for proof, well my engine has over 100K miles on it and still fires the first try and still makes good power.

[Tempest]

Thanks.

Well, two things re. your post.

First, I suppose I don't generally warm a engine up a LOT before starting off, though if I'm honest it depends on the conditions, and how well the bike is running, if the engine stalls due to being too cold, then you could easy end up toppling over as you lose all drive, but of course, that's something you learn due to how the bike is, in what temperature, and/or how long to leave choke on for.

I'm more interested in your side stand remark. I'm genuinely interested, as I've been letting my bike, the past 3 evenings, get up to "fan kicking in temp" to get things flowing again after a long standing without running etc etc, and for pretty much all of these 3 evenings, lets say 10 mins each time the bike has been on the side stand.

I'd like to know why being on a side stand is bad. The way the petrol lays in the carbs perhaps?

[bigtwinthing]

oil on 1 side of the engine, all over to the left etc.

[Tempest]

oil on 1 side of the engine, all over to the left etc.

In theory yes, the surface of the oil laying in the sump will be at say a 10 - 15 ? degree angle Would that make any difference to the oil being pumped under pressure around the engine though?

I don't know. But I take your point, irrespective of anything, it's probably a good idea for an engine to be upright when running

[8541Hawk]

The easy answer is that is what the Moriwaki Tech told me...... it is not good for these engines to sit and idle on the side stand.

They were here for that basically unknown American VTR racing program, but that is another story.

I didn't press them for the reasons, just a thank you for your time.
I will add the only VTR I have seen let go (yes a auto cct failure but not on my bike) was when....you guessed it, while it was "warming up" on the side stand (some folks refuse to listen)

I will admit I don't have a cut and dry answer to why it is bad to do, just I have followed their advice and have never had an engine or cct issue with all the miles I have piled on.

[VTRDark]

I'd like to know why being on a side stand is bad. The way the petrol lays in the carbs perhaps?

How about the fact that the oil pump is on the right hand side of the bike and when on the sidestand it leans to the left. Combine that along with the lack of oil the front CCT gets fed. So yes if your running the standard Honda tensioners it could be asking for trouble.

(:-})

[Tempest]

I'd like to know why being on a side stand is bad. The way the petrol lays in the carbs perhaps?

How about the fact that the oil pump is on the right hand side of the bike and when on the sidestand it leans to the left. Combine that along with the lack of oil the front CCT gets fed. So yes if your running the standard Honda tensioners it could be asking for trouble.

(:-})

I am guessing, however, given that if the oil at the bottom of an engine was at the correct level (not really low) I would never think any engineer/designer would ever make any engine, whereby being held at a slight angle (side stand) would mean there was any less than a full supply of oil being pumped thru all the internal oil ways. Especially when being on a side stand is part of the design of the bike.

I would be shocked to hear of any design that mean the engine was in danger of lack of oil due to being leaned over a little bit.

[Watty]

The oil pick up pipe will I assume be in the centre of the sump! Therefore if the oil is not low the engine will be getting fed oil pretty much the same as in the upright position! I'm sure Roger D told me the only issue is if OEM ccts are fitted and the r/h side one can be slightly starved of oil!

[8541Hawk]

I am guessing, however, given that if the oil at the bottom of an engine was at the correct level (not really low) I would never think any engineer/designer would ever make any engine, whereby being held at a slight angle (side stand) would mean there was any less than a full supply of oil being pumped thru all the internal oil ways. Especially when being on a side stand is part of the design of the bike.

I would be shocked to hear of any design that mean the engine was in danger of lack of oil due to being leaned over a little bit.

This is kind of why I don't bother too much with this topic.
Everyone wants a explanation and no one wants to believe that running a bike on the side stand is bad for it.

There are many theories on why this can be bad but I tend to look at it from a different angle.
No where in anything Honda has published does it say to start and\or run the bike on the side stand.
In fact you are told not to do this as the bike can fall over.

Even then, if you follow what Honda tells you, you first get on the bike (so now it is standing up) and then start it.
They also do not give any instructions to sit and warm the bike up, it's a water cooled bike and doesn't need an extended warm up.

So it is what it is, you can follow the couple simple instructions or you can do it your way.
All I will say is I have run my engine over 100K miles, all with the unreliable Honda auto CCTs, with no issues.
Is it because I do follow those rules, I believe the answer is yes.

As for my Moriwaki comment. For the newer guys, Moriwaki not HRC did the development on the VTR.
They also had the English program (Revolution) that ran in BSB that you know about but there was also a US program(Erion Racing).

It is not well know as the bike never made it to the AMA.
The reason for this had to do with the team rider and the championship run.
You might have heard of the guy as their #1 rider was Miguel DuHamel.
Then the "up and coming rider" was this other kid, Nicky Hayden.

So with that they decided the only place to test the bike was AFM club racing.
Which was a bit of a "home coming" for Honda USA or Erion Racing as it was known.

This is because Erion Racing was started by one of the Erion brothers after the two if them split up their first company.
They started that one when they were racing in the AFM and saw a need for NT 650 bits and formed the first business, which you also might have heard of, Two Brothers Racing.

When they showed up with the racing VTR they also had a couple Moriwaki guys besides Bob H.
Unlike a BSB or AMA race the atmosphere was much more relaxed and the guys were very approachable.
They told me don't run the bike on the side stand, not that you should run any bike on the side stand but this one really doesn't like it.
I didn't ask why just took the advice, besides with their limited English I doubt I would have understood the answer as I don't speak any Japaneses.

Which is a long winded answer...... the short answer is you can believe it or not, I live by it and have run my engine hard for over 100K miles and it is still going strong.

[popkat]

I think it's only fair Hawk that you state how many CCT's you've changed in that time, for anyone reading this it does come across as you've done over 100000 miles on the original tensioners. Even if you've had none fail you Have changed them.

If there's a potential problem with the CCT's if the bike is left running on it's stand it isn't proven and Honda don't mention anywhere that the CCT's are a service item, just the same as they don't mention starting up on the side stand, but hasn't stopped you changing tensioners

Personally I always start a bike from cold holding it upright or on the centre stand, not leaning over on the stand, I do this as oil in the top end can pool to one side of the engine leaving the right side of the top end with less oil, by holding it upright to start the bike the oil is dispersed more evenly, on start up it takes a moment for the oil to pump to the top end and start lubricating properly. A few seconds after starting I will lean it on the side stand while I put my helmet and gloves on. I've always done this and never had any engine issues that could relate to it, I've no idea of the mileage I've done but it's a lot, 30 years of road riding, 15 of those as a courier, I've taken bikes over 100000 miles, I guess I must have done somewhere near half a million miles on bikes.

Not having a go Hawk just saying that the issue of running on the side stand without specific proof on the VTR1000 is no different to any other bike. As for CCT failure there's no proof as to why that happens either, I've heard of extended overrun on the engine can contribute but I'm more inclined to think it's a corrosion issue due to a lack of oil feed to the front tensioner as this is the one that fails far more than the rear, that combined with a spring coil that's probably too thin and fragile in the first place.

[Tempest]

Thanks for the great and really interesting replies.

Being, kinda in Engineering for years, albeit on the Toolmaking/ Toolgrinding side of things as opposed to the Turning side of things (though I do use a lathe from time to time if I need to) I do have a very logical (I hope) mind, and tends to be pretty black and white. I want A and B to give the answer C. Not a fuzzy ish C.

Why I'm not THAT great with fashion and style perhaps as they are not things that are right or wrong, but judgements.
Like go to buy a watch, and see 200 in the window and think oh god I've no idea
Mainly due to the fact I can appreciate good points of many of them, Perhaps like a bike, I'd like an offroad, trail sports roadbike racer/tourer with a low down grunty, smooth electric silent / loud motor

One thing cannot do it all.

Going back to the sidestand/starting/running issue. Yes. 100% I love to know what the correct way of doing things is.
You tell me the correct way, I understand why it's the correct way (technical/factual reasons - Not made up opinions based upon a feeling of what's probably right) And I will stick to "The Right Way" forever.....

I know, part of the Internet issue is we are all individuals and all have opinions. Some do tend to post a personal opinion as a fact.

(Is that dress Black or Gold/Yellow!)

For me, the above was simple. Take the image in photoshop, read the colour values and that's it.
The dress in RL may be black, however in the image it was a gold/yellow. that's factually correct

Re my VTR...... I'm VERY pleased that since cleaning my carbs totally and a fresh, totally spotless fuel filter and tap diaphragm, that my VTR I'd say starts easier now than it ever has. Without choke on the 1st press of the button.
I'm sure, simply due to time wise, it would not hurt it to have a "tune up" by someone who could give it a "good going over", but It's running pretty nice

Just have to buy the missing spring from my rear brake assemble (re other thread) that I'm guessing was the reason for the sound being transferred thru the frame as the pads were not sitting on the spring, but instead on the metal of the swing arm in the cut out for the spring.