[PDB]

Hello All,

I've had a quick search on this site and elsewhere to see if I can identify and find a fix for the noise I've been hearing when I start my Bullet 500 engine from cold and lasts for up to a minute before it settles down, but can't seem to find anything that specifically describes what I'm hearing. It's a 2020 model and has just done over 5300 miles, this noise has been happening for the last 2000 miles every time I start it up, although it doesn't seem to change the usability of the bike. I've got a video of it on YouTube, via the link below:

https://www.youtube.com/watch?v=xyPAKcuqYbM

The sound appears at around 15 seconds in and seems to be coming from the front of the engine, near where the crankshaft is. Thanks in advance.

[Haggis]

I would be having that clutch cover off and have a look.
Primary chain rollers can break up.
Primary chain tensioner or blade.
Sprag clutch bolt can also come loose as well as the clutch centre nut.

[Ove]

What is the bolt in the alloy case, above / in front of the gear shift?

[Bilgemaster]

Seeing as how the primary chains of UCEs are a known issue, with many having been reported here as breaking after as little as 7,000 miles, you might do well to have a good long close look at yours at 5,300. In fact, I expect many who've suffered such primary chain breakages, with sometimes catastrophic collateral damage, might urge you to just replace it with a finer quality one right now, however sound that OEM chain may appear. There's plenty of info on this primary chain issue and recommended replacements in the Forum Archives. Suffice it to say that our Forum hosts Hitchcocks should be able to fix you up with a better-than-OEM replacement.

5,300 miles in a single year is rather more than most put on their Bullets. I've managed only just a bit over 13,000 on my Iron Barrel in three years, and thought that might be a lot. So yours has clearly earned a little pampering.

[PDB]

Thanks for this.
I have in fact checked the condition and the tension of the primary drive before from the external port above the gear lever, seemed fine then, although I will get this replaced now. Would this be classed as warranty work for the dealer, since the warranty still has 18 months left on it, and I'd expect any engine and its internal components to last much longer than 6 months and 5300 miles especially with the strict oil and filter maintenance regime that has been followed? I am reasonably handy with tools, so if it's best to leave the dealer out of it, then I can also do the change myself.

[Haggis]

The auto tensioner keeps the chain very tight. What did you find when you checked the tension through the inspection cap? The clutch cover is usually fitted without a gasket from the factory.  If you are taking it off for a look, Hitchcocks supply a gasket for refitting. Dealer is unlikely to spend time looking for the cause of stange noises.

[Bilgemaster]

Thanks for this.
I have in fact checked the condition and the tension of the primary drive before from the external port above the gear lever, seemed fine then, although I will get this replaced now. Would this be classed as warranty work for the dealer, since the warranty still has 18 months left on it, and I'd expect any engine and its internal components to last much longer than 6 months and 5300 miles especially with the strict oil and filter maintenance regime that has been followed? I am reasonably handy with tools, so if it's best to leave the dealer out of it, then I can also do the change myself.

Hmmm...that's right: You've got a warranty. And that poses a tough conundrum. I mean, assuming a fresh primary chain were covered by the warranty (and one might have thought so--though some items like tires or even final drive chains could be excepted as arguably being "consumables", barring some obvious defect), it still poses that big question: Would you even WANT a new OEM chain if such chains were known to often be defective, or at least of such subpar quality and prone to failure as to have become fairly common knowledge, even infamously so, among owners?

It seems to me that the fairest resolution might be to obtain a proper chain from, say, Hitchcocks, and either have the dealership replace the chain or do it yourself, should you prefer, with the dealership (that is, Royal Enfield) compensating you at very least for the retail cost of an OEM chain.

That seems a fair enough arrangement for all concerned, yes?

[axman88]

Your video does sound like primary chain interfering with something, but why would it go away after a minute of running?  The video ends before the sound ends, although it does seem to abate some near the end.

I'd be inclined to verifying the definitive source of the issue, before buying parts, calling dealers, or making any decisions.

I'd pull the primary cover, find the issue, then decide whether to involve the dealer or not.  My opinion (from reading here and elsewhere, I do all my own work), is that for various reasons, a lot of RENA dealers seem unfamiliar with, and/or unenthusiastic about the RE singles.  I don't think the OP said where they are located, and perhaps their local source of factory support is quite good.  If I decided to take it to the dealer, under warranty, I'd avoid stating that I had opened the engine case.

[PDB]

Thanks for the further help and advice.
I live in Staffordshire, in the UK, so parts shouldn't be a problem since Hitchcock's is the nearest local major parts supplier. Would this be the improved chain?: PART No. RN/114038/80A. That's the Renold's 80 link chain on Hitchcock's website.

The bike was purchased from a MotoGB dealer in Staffordshire at the start of June this year, MotoGB being one of the official dealer franchises in the UK. Since the purchase was from them, I believe they would be responsible for the warranty repairs if they were required.

During the inspection of the chain through the port, although there was no chain slop when the engine was kicked over, I could deflect the chain relatively easily with light pressure with a screwdriver. I've read on other forums to expect up to 1/4" deflection when cold.

If I were to make a more conclusive diagnosis and remove the clutch cover, can the clutch cover be resealed easily without the Hitchcock's gasket? If not, letting the dealer open it first may be the least painful solution, since they are sure to suspect that someone else has been fiddling around inside if there is a non-factory gasket in there. It has also been snowing here, and any work I do tends to be outside...
If I do go back to the dealer, I will inquire who supplies them their parts, and suggest that they use an improved chain if they want to use the original OEM chain. While I can understand that they would be reluctant to go chasing a strange noise around, I'd hope that they'd want to fix it now while it can be done relatively cheaply than to leave it to fail spectacularly/properly and require extensive repairs or worse.

[Haggis]

You won't know if is the chain until you open it up for a look.
The Renold chain is of much better quality than the oem one and is the one I use.
1/4" play was for the older manual adjusted primary chain. The automatic one has little or no play at all.
Until you have a look there is no way of telling.
It may be the sprag clutch bolt coming loose. I have seen pictures of the bolt lying in the bottom of the chain case.
Clutch centre nuts are not always tightened up.

[axman88]

I could deflect the chain relatively easily with light pressure with a screwdriver. I've read on other forums to expect up to 1/4" deflection when cold.

When I had my inspection port off and poked at my primary chain, there was a little deflection, on the order of 1/8", and although it wasn't scary tight, it felt quite stiff.   Yours sounds quite a bit looser than mine.

You have reminded me that I intend to take off the cover and check the primary chain at the next oil change, based on the reports I've read here of the auto-adjusters being too aggressive.  A broken primary can make for a catastrophic event as Haggis' excellent image illustrates.  Not much room inside that case to tolerate orbiting junk.

[Haggis]

Broken chain can be very costly,

[gizzo]

I'm probably not telling you guys anything new but anyway...

I have a feeling (no research, just an intuition) that the spring loaded and ratcheting primary chain adjuster has the same problem as millions of auto cam chain adjusters on Japanese bikes and as everyone knows, they are notorious for early failure on some models and the Achilles' heel of otherwise bombproof engines. Hence the profusion of manual adjusters in the aftermarket.

It seems like as the engine heat cycles, the chain loosens up, the spring and ratchet do their thing and the chain tightens up. Engine cools, chain shrinks, pulls insanely tight. Ratchet can't let the chain loosen off. Couple that with poor quality chain, it's not lasting long.

Like I said, that's pure speculation on my part. My experiment has gone thus: I replaced the stock chain with a good one from H (I loctited and properly tightened the primary and clutch nuts while I was in there) No problems there. Checked the chain tension a while later and of course it's stupid tight.
I removed the tensioner, removed the spring and reset the ratchet. Replaced the tensioner, minus spring, and set the chain tension manually by poking a small screwdriver up the tensioner body where the spring would normally be. I set the tension about like what the spring would give when it's installed initially. Difference is that as the engine heat cycles, there's no spring in there to overtighten the chain. I popped the cover off the other day after 10,000km. It's exactly as I left it. Not loose, but not too tight.

I removed the clutch cover several times to do this experiment but now I'm happy with the result I think I could adjust the chain next time (if it's needed) by removing the plug in the tensioner and poking the screwdriver up there and do it by feel. Any slack, you'll feel the ratchet click once with very little effort. That spring is very weak so adjusting manually also needs a light touch.

Anyway take it for what you will, IME, FWIW, YMMV etc.

[gizzo]

...

[Riffhead]

Hi there, I have the same model and colour I bought new in June 2019 down here in France. I've done 20,000 kms and haven't had any problems at all until last week cleaning the chain I noticed the mouvement in the rear sprocket. It's probably the cush rubbers but hey, it's still under warranty so I've booked it in to my local dealer. I have told the dealer there's a problem I would like them to fix, no one has mentioned the 2 year unlimited mileage warranty  yet. When they fix it I'm fully expecting them to say " No problem sir all fixed and covered by the warranty". If they dont say that and present me with a bill I shall say " Hang on a minute old chap surely it's covered by the warranty, I mean it's not tyres or brakes and it is an unlimited warranty etc etc." Which ever way it will be fixed and there will be some negotiation on price vis a vis warranty.
I've watched your video and that's a horrible noise, under no circumstances can the dealer tell you that noise is normal or ok, I would be straight back to the dealer and asking them to sort it. As soon as they mention prices and stuff remind them its an unlimited warranty and your well within your rights the bikes only 6 months old FGS. I would just add it's a fantastic bike, you are probably having doubts as I did but stick with it, I've changed the handlebars for higher wider motocross style ones, DNA air filter, and 1 tooth up on the front sprocket from 17 to 18. All simple stuff the rest is stock and I still have as much enthusiasm today as I had the first day to ride it as much as possible. I went out this morning to the bank 6 kms up the road and yes once again ended up doing 30 kms before I got home. I have to say since I've had this bike and it's not my first bike, the wife is not happy. Gary where are you...... 
Here's a link to my sprocket mouvement problem. https://youtu.be/posRO-CmFrk