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High frequency vibration


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What are the plugs gapped at? Are they "R" plugs (don't use) and are the leads OK? Wire type. not carbon thread. If it's a sharp miss, it's usually electrical. Nev

 

 

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All good ideas & I appreciate them all but I have good news.....finally!

 

I rewired all wiring that exits that hole on the case that comes from the stator. Those same wires going to the ignition switch up front were old, had multiple connections & were of various sorts of wire material.

 

I replaced all that with high quality, 14 gauge stranded, cleaned the ground at the switch with a new ground wire, made new connections and.....no more electrical miss!

 

You're probably asking yourselves, "Why didn't this dingbat do that to begin with?" The answer is no excuse but it has been working fine with those wires for 19 years. I just figured it wasn't the wires. Stupid I know but there it is.

 

Now the problem is mid range abnormal vibration. When the needles rise above & lets the main jets have at it, it purrs like a kitten from 5k to full power. When I back down below 5k to mid range, here comes the heavy vibration. I think there is a mismatch in the slides. Next job is to get the two slides to work in harmony & I "think" that will cure my mid range blues!

 

Thank you all very much for your help. That miss was a bitch to cure! I tried everything but the obvious! Lesson learned.

 

Bill Catalina

 

 

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While you're in there, check that both needle are in the correct slots and are straight and have no wear, then make sure that both cable outer ends are properly seated in their respective sockets. Probably wouldn't hurt to have a look at the inner as well. I had to change one recently as it was fraying.

 

 

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Will do! Thanks M61.

 

While you're in there, check that both needle are in the correct slots and are straight and have no wear, then make sure that both cable outer ends are properly seated in their respective sockets. Probably wouldn't hurt to have a look at the inner as well. I had to change one recently as it was fraying.

While you're in there, check that both needle are in the correct slots and are straight and have no wear, then make sure that both cable outer ends are properly seated in their respective sockets. Probably wouldn't hurt to have a look at the inner as well. I had to change one recently as it was fraying.

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Hi Bill, This may help you.....Bing 54 Carburetor Jet chart for Rotax Engines...

 

Bing 54 carburetor jetting, Bing 54 carburetors jet chart for Rotax aircraft engines.

 

Franco.

 

 

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You mentioned a "harmonic balancer before, I use a "Balance Master" on my prop flange, it makes a huge difference. link below:

 

HOME

 

 

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M61,

 

I was hoping somebody would answer that. Thanks. I had tried one years ago with no noticeable improvement. However, knowing me, it could've been something I neglected at installation.

 

I'll give it a try. If it works as you say, I'll buy another for my Trike.

 

Thanks again!....and for the link.

 

Bill Catalina

 

You mentioned a "harmonic balancer before, I use a "Balance Master" on my prop flange, it makes a huge difference. link below:HOME

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I don't know how you could screw up the installation.....you just bolt it to the flange with your prop.

 

I know it made a big difference to mine through the whole range. I had previously used a a dynamic balancer with good results, but I still had vibes in some of the range. I told a friend ( another maintainer) about them, he was impressed enough to become a distributor for them here.

 

 

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I just wrote them for info. I've got a 503 with a 60 inch IVO on my Drifter. Which one did you order if you don't mind my bugging the heck out of you. I found their site to be a little un-explanatory as to ordering.

 

As for screwing something up, I'm a master at it. But the one I bought was at least 30 years ago & it was smaller than their 7 inch version.

 

Thanks!

 

You mentioned a "harmonic balancer before, I use a "Balance Master" on my prop flange, it makes a huge difference. link below:HOME

I don't know how you could screw up the installation.....you just bolt it to the flange with your prop.I know it made a big difference to mine through the whole range. I had previously used a a dynamic balancer with good results, but I still had vibes in some of the range. I told a friend ( another maintainer) about them, he was impressed enough to become a distributor for them here.

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  • 3 weeks later...

Callahan, I'm gunna go out on a limb here, 2 stroke rotax engines are similar to 2 stroke motorcycle engines, with you breaking down and rough running issues I just wonder, Had an old BSA Bantam years ago and had a heaps of issues over a period of time, myself and mechanics couldn't solve it, went for a long ride one day and got so bad I had to stop luckily it was near an old fashioned bike shop, the old guy had me up and running in quick time and just a few bucks, seemed the capacitor in the points was faulty and once fixed ran smooth as, as the Rotax 503 has two capacitors just wondering if that is part of your running smooth issues. Showing my age on this is irrelevant lol [/url]

 

I have a 503 in pieces here and checked the ignition system and has two capacitors

 

31 in diagram is the two capacitors

 

Bosch ignition, Rotax 503 Bosch points ignition, Rotax points, Rotax condensors.

 

 

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PS: have also driven many old cars that had a high frequency whine, from memory an inline frequency suppressor on the high tension leads from the coil usually fixed that, just an idea. Hope you sort your problems they can wear you down trying to source them.

 

Engine noise

 

Noise introduced through the power and ground wires connected to your receiver is called engine noise (sometimes referred to as “backway noise”). If engine noise is your culprit, you may hear a whining or clicking sound. Its pitch will usually vary with engine speed.

 

If this is the case, you can install an alternator noise filter on the power line between the battery and the alternator to minimize the problem. You can also install a noise filter on the receiver's power lead to cut down on signal pollution (American International's S15A (15-amp, 250-watt) or S25A (25-amp, 350-watt) filters, for example). Most often, however, backway noise comes from a loose or intermittent ground connection. See the section below about noise in the electrical system.

 

noise2.jpg

 

An alternator noise suppressor connects inline between the alternator and battery, and can reduce high-pitched whining noise that modulates according to engine RPMs.

 

 

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Aussie & all the rest of you helpful guys!

 

Right now you're showing how much more intelligent & mechanically inclined you are than me. I can only dream of so much brain power. I'm being serious - not silly.

 

I may have confused you on the problems too. The high speed or high frequency vibration is on the 503 Drifter while the heavy low frequency vibration is on the 503 Trike I also have.

 

Through a video I made for YouTube for my Ace mechanic, he has now concluded that the Trike's heavy vibes are interior (something way out of balance) like crank fittings. He will fix it & I intend to post the results on here soon.

 

Concerning the high freq. vibration on my Drifter, I have gone through everything external (literally everything) and also bought two new $$$ coils. No help. And two Balance Masters. No help. I have done a top overhaul, did find quite a bit of carbon, cleaned it all. No help. Rings were loose and good. No sign of piston damage. No help. Compression is good at 110 psi both. I continue to plow through it but other than tearing it down to the crank, I can't think of anything else except pull the flywheel & visually check the triggers & stators for any metallic matter, grounding etc. After that, it's Crankville too.

 

Only I have mysterious problems like this that stump not only me but people smarter than me!

 

I sincerely appreciate all of your help. I will post results here as soon as known. I will take your advice & if possible, proceed as directed or as far as my limited brain power will allow.

 

P.S. I'm 68.

 

Callahan.....misery loves company!

 

 

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Geoff,

 

You mean those 10 or 12 washer looking things? No, I haven't but the B-box is new. Going for the easy stuff first.....the triggers & stator. I meter tested them externally & they checked to spec but still...

 

Then I tear into the ass end . Gotta' buy a press first. Looks like I'm working my way into my own overhauling.

 

Thanks!

 

 

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Hi Bill, Have you checked your Props for balance? Doesn`t take much to put a Prop out of balance and that certainly would cause vibration.

Franco, Ps, I`ll be 70 on 01-01-2018....Cheers.

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Farri,

 

Thanks for the reply but I bought a new IVOPROP just for the vibration & a Balance Masters (2). Both no help.

 

If you're referring to the heavy vibration in the 503 Trike, it is currently with the Doctor. Will post a Rx ASAP.

 

They high frequency vibe on the Drifter is in my minimally skilled hands. It may be going to the hospital too.

 

Will post all. Thanks again!

 

 

Hi Bill, Have you checked your Props for balance? Doesn`t take much to put a Prop out of balance and that certainly would cause vibration.

 

Franco, Ps, I`ll be 70 on 01-01-2018....Cheers.

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  • 3 weeks later...

I see you are advertising for a Rotax C gearbox......do you have a definate cause for your vibes then? If your prop is good but you have a heavy prop frequency vibe I would suspect something wrong there (the box). Did you find a problem (shaft? gears? override clutch? bearings?) or are you just troubleshooting?

 

 

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M61,

 

I changed gearboxes from C to B. Did not change the vibration. I even changed the muffler, the carbs, added Balance Masters. Nothing helped & still doesn't.

 

I need a C-box because I tow hang gliders & banners with my Trike. In the whirlwind of trying to figure out a Drifter hi-speed vibration solution, I let my C-box go in exchange for labor thinking it was the cause of the vibration. Big mistake! C-boxes are hard to find & very expensive.

 

Currently, the Trike engine is at my overhauler's. He still can't quite nail down the cause of the heavy vibration. Tore it down all the way to crank. Checked all tolerances, bearings, checked the flywheel, fan & shaft. All checks okay.

 

I told him the damn thing is haunted.

 

 

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Hello Nev!

 

Mechanic took it all the way down, pulled the crank, checked everything there is to check. Vibration is "less" he says but still there. It's on its way here now.

 

I'll put something online when I install it. I'll just have to keep it out of the 4k to 5k range. This is the first time he has not been able to diagnose a problem motor.

 

 

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