Unofficial Royal Enfield Community Forum
Royal Enfield Motorcycles => Bullet with the UCE engine => Topic started by: emskee on August 26, 2009, 04:59:19 pm
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Folks,
The thread titled " Engine dies & sudden thrust.......why?" ended with where the mixture adjustment screw is and advice not to toy with the bias on the TPS. However, no answer was given on what might be the cause of or the solution to the problem.
At the stop, my C5 still idles high, drops to a low RPM and can/will stall if I do not blip the throttle.
If I keep a "slight" bias on the throttle (small twist pressure - just enough to feel the stop plus a little more) she will hold a more slow and steady idle (less extreme up and down RPM rates) and be okay. Just like what would happen if the TPS pot were given a nudge. Could some bikes be on the edge as per factory set up? Mine is one of the first C5s to hit the US of A (mine had the gear recall).
Factory have any ideas on this?
Thanks so much.
Mike
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It sound like an air leak. Spray some WD-40 or carb cleaner around the intake manifold while the engine is running. If running is affected ( RPM change), you have your answer.
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thanks
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Been messing with "fuelie" bikes for a while now, could also be a vacuum leak my Kawasaki did about the same and found one of the vent lines from the tank to the injection body had cracked. Replaced a small section of hose and the problem went away. Will.
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Is this with the bike hot or cold?
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It does it from start and throughout my 90 minute trip to work (or back). So...cold and hot and in between.
I'm going out this afternoon to give it the eye. She's been parked for a few days - monsoonlike rains dictated that I take the Ural to work. (Once I got used to three wheels in the rain and snow, the two wheelers just don't make sense any more.)
Later
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I think I got it!
(However, this is my 5th bike, I do most of the work myself and I note that when I post a fix to a Forum, there is at best a 50/50 chance that it stays fixed.)
Those who posted that I had a manifold leak, please take a moment and, using due caution so as not to pull something, reach behind your selves and give yourselves some pats on the back.
Loose connection of manifold to intake.
Little turn on the hex heads. Hit starter button. Started right up, hit steady idle and stayed there.
Today on ride in, 45 degrees out, 90 minute ride. Started right up and stayed started. (Before I had to keep blipping throttle for like 3 minutes before I could take off.)
Stalled once on way in after I had to go from 45 mph to stop in like 3 inches. Bike went to idle and kept going until it stalled. That could happen with new engine I reckon.
Each and every other stop she went from a tall (though not as fast as before) idle to a low idle, hang out there for a bit, pick it up a bit and hang out a a nice pace until the light got green.
I'm happy. Life is nominal.
Thanks all.
Mike
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Good find! - And a good thing to look for. The torque on the bolts from the factory is quite minimal, as the oring's on either side of the heat insulator just need to seal - they don't need the life crushed out of 'em. I could see the potential for the bolts to loosen up a little during heat cycling. A good test for leakage would be to *piff* a little WD-40 around the manifold connections and see if the idle changes. If you DO have to adjust the bolts, use a drop of blue Loc-Tite to hold them in place after you gently tighten them.
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Monsoon like rains, so you take the Ural. Them's tough bikes. ;D
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You know, I had a Harley with a spent O ring on the intake manifold to the rear cylinder. WD-40 test didn't do anything to RPMs. Replacing the ring did.
I had a warped carb flange on the Ural. WD-40 didn't do anything to RPMs even though I could HEAR the damn air whistle past the flange on aspiration.
So...I don't trust that test.
By the by, on the trip home today, not a single problem.
To be sure, I didn't fat fist the flange bolts. I did the single finger torque wrench thing and still got about a 1/4 to 1/2 turn before the bolts seated. Then I stopped.
I'm gonna avoid the Loc-Tite for now and just sit back and watch and see if they loosen up again.
Regarding the Ural: I have a 2005 Gear Up. That dern rig is cat's can in the rain since I got rid of that RPOC air cleaner and installed the Modtop with the two K&N filters and the opening to the bottom. (BRW, does your 2006 Patrol pull air from the top or the bottom?) Old Svetlana used to suck a lot of water and stall out now and again in rain (and snow). Now I can take a ride that fills my boots and she doesn't miss a beat. Them's tough bikes for sure.
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Pulls from the bottom.
I recently dumped the cats, rejetted, and added the mikuni compliance fittings. Runs great now, but mileage took a hit.
I want to do the modtop pipes, but I thought his air filters were pricey and I don't like K&N's.
I think I'll do the Dnepr airbox mod.
You on Soviet Steeds?
sorry for the hijack
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I think I enabled the hijack.....
I'm on Soviet Steeds also as EMSKEE. Haven't been there for a while. Seems like the same old topics keep rolling through. And now that Svetlana is no longer named Olga the Chronically Ill Incontinent Pack Mule, I don't have much reason to be there. All the fixes are in, I reckon, so it is just maintenance and wearout from this point on.
Since putting on the MonTop air cleaner, and with stock pipes, I finally chased down my jetting and shimming (42 slow, 137.5 mains, 0.065 shims). Went to the Mikuni flanges after two go arounds with OEM hard mounts which wouldn't hold and some rubber Mikuni knockoffs (from a reputable Ural dealer) which went teats up after like 1200 km. The Mikunis I like. Probably have 10,000 km on those. BTW, I get 40 mpg (yes MILES per g) and tan plugs to boot. Go figure.....
I like the K&Ns since I bought the cleaner and oil like 10 years ago and still have a lot left.
Listen, good commiserating. See ya around.