Author Topic: Lost the top end power  (Read 2072 times)

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BRADEY

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on: May 11, 2011, 01:07:32 pm
Hi, I have a 2003 CDI ignition Royal Enfield Electra 350. The bike has clocked 40,000 kilometers so far. Although it seems to run smooth, however it has lost its "appetite" for the top end power. The bike is taking more time to hit top cruising speeds and very reluctant to do its top end (110 kph). I have had the clutch assembly checked and verified but there is nothing wrong there, the carb has been overhauled and cleaned completely and yet the situation persists. Could it be carbon deposits that is robbing my bike of its performance ? What else.......any suggestions please. Thank you for your feedback.


GreenMachine

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Reply #1 on: May 11, 2011, 03:45:57 pm
have u done a compression test of the cylinder ?  I would check to see that u r getting the correct pressure reading for a 350 cc enfield...you bike puts out about 18 hp stock..per snidal manual u should be seeing 110 psi  plus or minus 5.. Yes if u have access to something like seafoam, its not going to hurt to give that a try either.....good luck and keep u inform on your progress..cheers
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cyrusb

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Reply #2 on: May 12, 2011, 08:15:20 pm
It's not surprising at 40,000 kilometers. Like Green Machine said, check your compression, it may need a valve job, or a whole upper end rebuild.
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BRADEY

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Reply #3 on: May 16, 2011, 10:05:44 am
The spark plugs tells that the bike is being starved of fuel at higher speeds, resulting in sluggish pickup and lower high end speeds.

But the motorcycle was completely serviced a week ago, including "carb overhaul" so I cannot understand where could the problem be. I found a small pieces of carburetor flange (the fibre pieces used for filling and sealing the carb on to the engine intake) dangling from one of the flange...could it be that there is more debris in the engine intake that may be choking the engine ?? or is it the carb gone bad.......!!!


Chasfield

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Reply #4 on: May 16, 2011, 11:20:44 am
If the carb flange gasket is breaking up then that might allow air to leak into the inlet tract on the hot side of the carburettor, which would give lean fuelling.

Also, as other posters are suggesting, a compression check would be worthwhile.

Can you still feel good resistance at the kick start?

40,000 kms is a good run for British type air cooled 350. A top end strip down for decarbonisation, piston and valve checks and assesment of big end bush condition would be on schedule for that amount of engine run time.
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BRADEY

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Reply #5 on: May 17, 2011, 12:36:56 pm
Both my "gut feeling" and "owner's know how" tell me that this due to lean fuel mixture rather than anything else. It was first experienced when I got my fuel tap changed. The new one never delivered the same performance, but as I used this bike more for commuting, I did not take notice.

The compression seems to be alright from what the kick tells me, and by the way the bikes manufactured during that period have their engines intact in some case even after clocking 150,000 KMS. God knows how this happened.

Will try to change the petrol T, rubber intakes and fibre flanges that seal the carb on the engine. Hope it works out well......will keep you guys updated.


BRADEY

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Reply #6 on: May 21, 2011, 06:47:02 am
Happy to report that my "Gut Feeling" was correct and indeed the bike was feeling stressed at the top end, due to suction leakage between the carb and the engine intake, and yes she was running lean !

I removed the carb and applied thin layers of  "rubber gasket" on each flange and put everything back together. Took the bike for a short ride and there it was, the grunt in the engine was back and so was the willingness to accelerate to the top.

I will do some more test runs to ensure that everything is fine for good.....Cheers.