Question from a beginner

[iron.head]

Hi ace.cafe

Need your help in understanding something. I bought my C5 in January this year. My bike from day 1 of purchase would never start using the self-start without a little bit of throttle input. Changing the idling within specified limits never helped. However, few people whom I met at RE authorized workshop, showed that their bikes started without any throttle input at all. One mechanic also told that all new bikes coming from factory start without any throttle input.

Now few days back, I took my bike to RE workshop for the first time for cam noise issue. When the mechanic removed the RHS engine cover, he exclaimed that my bike has a specific set of cams which have been seen in few bikes and is prone to make noise and develop play. They replaced both the cams with different type ones and the noise which was there from more than last 6 months was gone.

Now my bike also starts using self start without any throttle input at all. Is there any connection between this? But now I have started facing another issue, which is noise from auto decomp during cold starts. This kat-kat type of noise was never there on my bike. I have tried increasing idling RPM but this noise is prominent. If I give a bit of throttle input during cold starts for half-a-minute or so, this noise is gone. But without any throttle input this noise doesn't go away for a long time. It might be due to the winters here but it was not there during last winters. How do I get this noise fixed? One person told me that it has something to do with a spring in the auto decomp.

On another note, are you aware of the multiple changes/improvements RE has done on Classic 500/UCE 500's. They are now supplying a third variant of the crank-shaft+con rod assembly where they have done something to save the con-rod from breaking in certain conditions. Earlier RE made the crank more balanced by digging some holes at certain places on the crank.

[GreenMachine]

hilltxn: I feel the same way..I prefer my heavier 1100 for any serious highway riding anyway...I love my little Enfield but she likes to be handled a certain way...I don't like to beat the crap out of it at 60 - 65 mph for any length of time...My first bike was a Honda 450 Nighthawk, dependable, great on gas and could do 65 mph all day....GM

[barenekd]

The cam change could definitely change the starting characteristics.
As for the decomp clack, mine does it when it's cold. Once it warms up a couple of minutes, it quits. The clatter, that is..I don't worry about it. It's been doing it for 15000 miles. The spring is probably screwed up, but I haven't had it apart to get into it.
Bare

[Blackcat360]

Since I am after a newer bike (fuel injection ect.) what's the oldest year I should look at?

[gremlin]

2009

[TWinOKC]

Since I am after a newer bike (fuel injection ect.) what's the oldest year I should look at?

In 2009 they offered both FI and carburated versions.  The older bikes = chain is on the left hand side.  The newer (UCE) = chain is on the right hand side.

[ace.cafe]

Hi ace.cafe

Need your help in understanding something. I bought my C5 in January this year. My bike from day 1 of purchase would never start using the self-start without a little bit of throttle input. Changing the idling within specified limits never helped. However, few people whom I met at RE authorized workshop, showed that their bikes started without any throttle input at all. One mechanic also told that all new bikes coming from factory start without any throttle input.

Now few days back, I took my bike to RE workshop for the first time for cam noise issue. When the mechanic removed the RHS engine cover, he exclaimed that my bike has a specific set of cams which have been seen in few bikes and is prone to make noise and develop play. They replaced both the cams with different type ones and the noise which was there from more than last 6 months was gone.

Now my bike also starts using self start without any throttle input at all. Is there any connection between this? But now I have started facing another issue, which is noise from auto decomp during cold starts. This kat-kat type of noise was never there on my bike. I have tried increasing idling RPM but this noise is prominent. If I give a bit of throttle input during cold starts for half-a-minute or so, this noise is gone. But without any throttle input this noise doesn't go away for a long time. It might be due to the winters here but it was not there during last winters. How do I get this noise fixed? One person told me that it has something to do with a spring in the auto decomp.

On another note, are you aware of the multiple changes/improvements RE has done on Classic 500/UCE 500's. They are now supplying a third variant of the crank-shaft+con rod assembly where they have done something to save the con-rod from breaking in certain conditions. Earlier RE made the crank more balanced by digging some holes at certain places on the crank.

Hi,
Sorry that I didn't see this post until someone brought it to my attention.

Anyway, cam changes can affect starting and idling behavior. I don't know what the cams which were removed were like. I have got measurements from one set of cams that one of the owners was kind enough to provide me. I don't even know how consistent these cam timings are from bike-to-bike on these models. I simply don't have enough data from enough bikes to say anything about that yet.

Regarding the auto-decompressor, that is simply a bob-weight type of mechanism with a spring. It's located in the exhaust cam, and when there isn't enough centrifugal force from rpms to swing the weight, it makes a little bump on the base of the exhaust cam, so that it momentarily dumps compression. It actually works similar to the auto-advance weights that are in the old Iron Barrel distributors. This can be adjusted with different springs, but they don't make different springs specifically for this purpose, as far as I know. Perhaps the spring you have in there will weaken from use over some time, and behave as you wish. From your comments, it sounds like it is sticking, and a good rev causes it to release if the bike is warming up. It might just be a little gunk stuck in there.
If you are really disliking this, you can see your dealer and make him aware that you feel this is a warranty-able issue, and that you want it fixed so that the noise is not heard at your normal idle speed.

On the crankshaft updates, I have not been aware of the factory changes in crankshaft assemblies. I didn't know these changes were happening, but it sounds like improvements.
I would have to know exactly what they did, to make any comment about it.
As for the balancing changes, this is something that normally would not need to be changed unless the moving parts were suddenly different. I don't know what they did.

[iron.head]

I would have to know exactly what they did, to make any comment about it.
As for the balancing changes, this is something that normally would not need to be changed unless the moving parts were suddenly different. I don't know what they did.

I had sent you a PM as I felt that this post must have slipped your attention. More information and pic of the second variant of the crank is available here:

http://www.team-bhp.com/forum/motorbikes/73998-royal-enfield-500-classic-thread-62.html#post2161237

If pics or some basic info about UCE parts is needed, I can try getting this info from RE Workshop in my city.

[ace.cafe]

Okay, well apparently they changed the balance factor of the crank.
On singles, the cranks are not really balanced, but they are just weighted to give the most manageable results at a certain rpm range. in this case it appears that the balance factor was changed to a percentage which gave improvement to a higher rpm range than previously was on the other crank.

We do this with the Fireball too, when we build the bike for more rpms.

[Lwt Big Cheese]

No one can tell you which bike is best for you. Only you can decide.

If you want a period bike and enjoy the ride get an Enfield. If you want an interstate rocket ship get a Honda.

Personally I would go for the oldest that I can afford. It will have been fettled now and run nice, and far fewer unecessary parts to go wrong anyway.