Unofficial Royal Enfield Community Forum
Royal Enfield Motorcycles => Vintage Royal Enfield => Topic started by: Gokul on May 16, 2020, 10:24:44 am
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Hi All,
I have a 1978 Enfield India Bullet Deluxe. It has not been used for two weeks. I uncovered it today and it didn't start. I turned the choke on and it started. The issue is that when I turn the choke off then, the engine dies. Even with the choke turned on, it runs as if the throttle was opened way too much. I close the choke and the engine dies instantly. I removed the carburetor, cleaned the float bowl, remove the float ball hinge pin, cleaned the float needle, cleaned the main jet and the pilot jet. I did not adjust the air mixture screw. It is as it was when the motorcycle was running fine. I do not feel that it might have to do anything with the idle screw. I have had my engine kill switch disconnected since the time the motorcycle was running fine.
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What type of carburetor do you have? Different makes were fitted over the years.
A.
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The carburettor is similar to the one on this URL.
https://www.ukscooters.com/pictures/prod_45_3.jpg
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That looks like a Mikcarb VM24. The "choke" may be compensating for a clog or air leak somewhere.
Remove carb, disassemble, and thoroughly clean it with spray carb cleaner--especially its jets. Wear safety glasses if you value your eyes! That spray will surely ricochet off in crazy directions.
It could also be an air leak at or near the manifold. It could be loose. Some Indian models also have a sort of extra air screw on the manifold to let in some extra air for very high elevations like for traveling up in the Himalayans. Check for one, and that it's not loose or missing. To check for such air leaks just get it running somehow and spray some carb cleaner, WD-40, or similar judiciously around the carb and manifold. If the engine increases speed you've found a leak.
If you've never played with a Mikcarb before, then you may find this guide from our Forum hosts useful: https://accessories.hitchcocksmotorcycles.com/core/media/media.nl?id=188646&c=1062795&h=89b0a7f48c59d757f7b1&_xt=.pdf
Good luck!
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You're spot on. There is an air leak between the carburettor and the engine. The carburettor is loose. The thread in the bolt and the nut have worn out.
I already removed the carburettor, disassembled it and cleaned it; especially its jets.
Thank you for the guide. I went though the video on the URL:
https://www.youtube.com/watch?v=p44VNddZ7Zc
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I managed to tighten the carburettor. I don not feel that there is any air leak now. When I turn the choke off then, the engine dies instantly.
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I managed to tighten the carburettor. I don not feel that there is any air leak now. When I turn the choke off then, the engine dies instantly.
Just to clarify, once the engine is running and reasonably warm, when you raise the "choke" lever the engine dies?
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When I raise the choke lever up, the engine dies. The choke lever on my carburettor is similar to the one on the URL below: My carburettor is not exactly the same though.
https://www.indiamart.com/mikcarbindia/motorcycle-carburetor.html#350cc-bullet-carburetor
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If the cleaning didn’t work, it may be time to rebuild the carb with a replacement parts kit. That’s ultimately what I had to do with my 77RE 350 to eliminate any carb related issues. Once the rebuild was done, it ran so much better.
Good luck.
Rob
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Gokul - you should be able to see through the pilot jets center. A Honda I worked on recently had pluggage in these jets from old fuel or other gunk in them. A piece of stranded copper wire yields an appropriately tiny tool to work through this orifice. WD40 is a "no harm no foul" solvent which may help. It also provides a clean pressurized spray through the red straw which is always helpful. Backblow the air bleed screw passages too. These carbs work 100% when clean, just some of the passages are tricky to access. New jets are always available from Hitchcocks.
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Cleaning worked. It runs now.
I am able to see through the pilot jet's center. I have a piece of copper wire to work through this orifice. I use WD40, which has been helpful. I am in India. There are a couple of websites, which sell new jets.