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How to replace engine oil & reset service reminder on a new Bullet 350

I think that this procedure should be the same for all Royal Enfield motorcycles with the J series 350cc engine (Classic Reborn, Bullet, Hunter and Meteor).

BHPian Viju recently shared this with other enthusiasts:

As soon as my Bullet 350 crossed the 450 km mark on the odo, the service reminder (spanner icon) started flashing on the tiny LED screen. I really did not want to ride one hour to my dealer just for an oil change. Plus I wanted the satisfaction of doing the job properly myself. However, it didn't exactly go as smoothly as I thought it would. Read on.

Caution: This procedure should be basically the same for all the J series 350 motorcycles from Royal Enfield (Classic Reborn, Bullet, Hunter and Meteor). However, please refer to the umpteen videos available on YouTube including the DIY videos published by RE if you are unsure of what you are doing.

Choosing the right oil

As the J series 350s take in somewhere between 1.5L ~ 2L of semi-synthetic engine oil of 15W50 grade (JASO MA2 or equivalent), I got 2L of Castrol semi-synthetic oil in the correct specification. I got this from a nearby Home Depot, and they did not have any other brands in this grade. But it was ok, as I believe in using a 'regular' oil and replacing it more frequently, than putting in something 'exotic' and using it for a longer distance. In any case, the J series is a simple, air-cooled engine which does not demand anything exotic to do its job. Also, please be responsible and dispose of the oil properly. It must not be poured into the soil or drained at any cost to prevent environmental damage.

Along with the oil, I also bought a few more things - a funnel, a tray and a used oil disposal kit. The oil change kit that I had purchased from Hitchcocks consists of an assortment of RE genuine spares (O rings, seals and washers) needed to do a thorough job.

Tools needed

4mm allen key, 17mm ring spanner, a ratchet and an 8mm socket. The nose plier can be used to pull out the oil strainer, but I ended up using just my fingers and recommend the same, as a ham-fisted approach with the plier can irreparably damage the strainer.

Procedure:

Place the bike on the center stand.

To ensure that the old oil completely drains out, it needs to be warm. If the engine is cold, I would suggest doing a short 5 to 10-minute ride, coming back home, switching off the bike and waiting for around 20 minutes or so for all the engine to flow back down to the sump, and then proceed to the oil change.

Touch the engine covers to make sure it is just warm and not hot. Also, beware of burning your hand on the exhaust!

Open the oil filler cap and keep it aside for cleaning

Soak the new oil filter in fresh oil and keep it aside ready for fitting

Place the oil catch tray under the strainer cover shown below

Open the oil strainer cover (near LHS rider foot-peg), using an 8mm spanner or socket

Caution: As you open the bolts, the oil will start flowing out. Hence it's necessary to make sure the engine is not too hot before you start. Also, keep some rags or highly absorbent wipes handy.

Just let the strainer cover hang onto the bolts for a while until most of the oil is drained out. Trying to remove the cover in one shot could end up in an oily mess.

The 480 km old oil

Gently pull the strainer out

The dirty strainer - keep it aside for cleaning

The painful part

Next one was tough - the drain bolt near the RHS rider foot-peg

Note: RE does not strictly recommend removing the drain nut as it is a pain to remove it, as I discovered. There is no way to unscrew it with a 17mm ring spanner as the frame blocks it. I nearly scratched my frame trying to unscrew it.

In RE's defence, they do provide a 17mm slim open-ended spanner which could be used for the drain bolt. But I could not open the drain nut even with that one as someone at the factory had decided to torque it to what felt like 2,000 Nm!

For guidance, I checked Stuart Fillingham's video on this topic and Stuart being Stuart, was able to unscrew the drain nut with a 17mm spanner, although he mentions it is not easy.

Consoling myself that it was only my incompetence that was to blame, I went to bed with the job half-done as it was getting dark. As someone who worked on automotive design in the distant past, I was wondering which nincompoop in RE signed off on that drain nut sitting right above the frame tube, with zero consideration for serviceability.

The next morning, I had a brain wave and remembered that the front part of the frame ('down-tubes') is actually a sub-frame of sorts and can be lowered down by unbolting the engine mount / crash guard lower mount bolts. In fact, I had done exactly this while fitting the heel-toe shift lever.

Fortunately, this worked and I was able to finally get my regular 17mm ring spanner in there to undo the drain nut. It was still a pain though, as it was torqued to epic proportions by none other than someone who could be described as a gorilla (not guerilla!) who was gifted his first power tool.

Also, I forgot to mention that the engine oil was overfilled in my bike from the factory or the dealer. Either way, it was not a good sign and I was kicking myself for not checking it during PDI. I now remember that the dealer had kept the bike on the side stand when I went for delivery. This basically meant that the sight-glass showed nothing!

I lowered the frame and finally undid the drain nut

This released another 50 - 100ml of oil, and I was finally satisfied

The water in the tray is due to me keeping the tray out in the night without thinking it could rain.

The last step in disassembly is the oil filter cover and filter.

The oil filter cover is held on by 3 x 4mm allen key bolts

The cover is spring-loaded

Press the center portion of the cover while unscrewing the bolts one by one

Once the cover is undone, expect more oil to flow out.

Keep a cloth to save your frame and exhaust from this oil.

Gently pull out the old filter to discard

Clean out the old oil from the cavity.

Note: Recommended to use a clean rag or kitchen wipe and not a microfiber towel as it could leave small fibers inside the engine.

Clean all the components using an O-ring safe cleaner. I used a brake cleaner.

Ready to go back in

One thing I forgot to mention is that RE had been using magnetic drain plugs from 2001 onwards. I believe they stopped using them from either the 650 Twins or from the J series 350s. It basically means they now have enough confidence in their machining process and QC that they don't deem it necessary to use a magnetic plug to catch any metal debris floating around in the oil.

I of course prefer to err on the side of caution and had ordered an older model magnetic drain plug. The thread sizes are the same, just that the bolt head is bigger at 19mm as compared to the original 17mm.

Also, as a good practice, always replace the copper washer when you re-attach a drain plug. It is meant to be a crush washer and may or may not leak if re-used depending on your luck.

The J series non-magnetic drain plug & the old magnetic drain plug

After this, it is basically the same process to refill the oil, but in reverse. Re-attach everything including the new filter and torque gently, remembering that you will need to open it again.

By the way, I did not have to replace any of the O-rings / seals other than the copper washer, as they were in perfect shape. I kept aside the news one safely for future use.

Once everything is assembled, pour in the new oil carefully. I could not take any pictures here as I was alone and concentrating on pouring the oil in without making a mess.

The first bottle (1L) went in without any oil even showing up at the sight glass on the right side. While pouring the second bottle (1L), I could see the oil level slightly rising. When it was right below the Max line, I stopped pouring.

As I did not have a measuring jar (I should get one for next time), I have no idea exactly how much oil went in. But there is still <500ml oil left in the can which I could potentially use for top-ups.

Run the engine and once it is warm enough, go for a short ride (may be 4 or 5 km), return and check the oil level after 15 minutes or so. Make sure it is still in between the Min and Max lines. Also, check all the places where you opened the covers and bolts and ensure that nothing is amiss and there is no oil leakage.

And there, you have successfully completed your first oil and filter change on your J series motorcycle!

Continue reading aboout Viju's DIY job for BHPian comments, insights and more information.

 
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