OzVMX Forum
Marque Remarks => KTM => Topic started by: pmcburney on March 27, 2011, 08:41:30 pm
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Bloody motoplat.
They've got a lost to answer for, especially after thirty years.
Anyway, the hitherto invincible 495 decided to strand me today. 100 metres after the start. Of the championship race - no 40 points for me.
The fire went out in a big way, so much so that I had to pack up my bat and ball and go home.
After much checking of resistances and fiddling and swapping, it seems that my last minute change to approx 32:1 has been my undoing.
With the spark being as marginal as it normally is, it seems any excess oil buildup (like waiting on the line for the line to drop) at ratios higher than 40:1 will quench the flame sufficiently to halt any further progress.
I'm now on the hunt for a replacement. PVL and MZ-B come to mind, but I'm wary because of the price of admission.
Has anyone had any experience with either of these two on a Kato?
And, how do I sort the twin-plug coil arrangement I currently have to work with either of these aftermarket kits?
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Move into the 21st century ::)
(http://i155.photobucket.com/albums/s297/Lozza85_2007/042.jpg)
Cheaper, and fully programmable.
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If you search 'motoplat' on this forum you will find links to some specialist Motoplat places i suggested in a thread for Paul. I have used the MZB (no longer called MZB by the way, they are now http://www.powerdynamo.biz ) and they a very good quality and work well. You can order directly from them http://www.powerdynamo.biz/deu/systems/lists/ktm.php They are made specifically for each model. The other option is to get yours repaired go the with the programable pit bike type stators like Lozza suggested. These are usually very cheap but you will probably have to do some modifications to get everything to fit on right.
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go the with the programable pit bike type stators like Lozza suggested.
Leith, Lozzas ignition is lightyears away from a Chinese pitbike ignition. As good as those Chinese ignitions are for the price, I've never seen a programmable one. PM Lozza PCM and he'll fill you in on all of the guff his ignitions. He's currently doing one on my 360 Yamaha engine.
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Yeah i know they are not chinese made, but they are cheaper than the Power Dynamos and you can plug them into your laptop and change the curves etc so in ways they are better;)
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Why not have the original motoplat rebuilt? There are a number of companies that do this.
No compromise on the flywheel weight! Here's just one place, there are others.
http://www.uk-motoplat.com/home.html
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Why not have the original motoplat rebuilt? There are a number of companies that do this.
No compromise on the flywheel weight! Here's just one place, there are others.
http://www.uk-motoplat.com/home.html
I can be sold on this idea.
If... it can be made better than it was brand-new.
If I'm going to shell out dollars on getting the OEM ignition fixed, I don't want it to be as-good-as-new, I want it better than it ever was.
That's why I'm thinking of going aftermarket. I'd reckon a more modern design and brand-new (modern) parts would be a move in the right direction.
I really want and need utter reliability.
This thing is enough of a handful when it's running badly. I still need to sort the brakes and the jetting - the sparks is the last thing I want to fiddle with or compromise for.
Thanks for the suggestions guys, I'll make some calls and send some emails and get some advice from the guys that do the work or sell the gizmos.
Hopefully it will be sorted by the next round...
Cheers
Paul
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where do you find the pit bike systems. i've rebuilt the 390, had the stator rebuilt. Put the bike together, had spark and still won't start, don't think spark is strong enough, so might look for an alternative
Barry
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Try this one Barry. Note free shipping!
http://cgi.ebay.com/inner-rotor-kit-flywheel-ignition-cdi-atv-pit-dirt-bike-/320663165992?pt=AU_Motorcycle_Parts_Accessories&hash=item4aa9039c28 (http://cgi.ebay.com/inner-rotor-kit-flywheel-ignition-cdi-atv-pit-dirt-bike-/320663165992?pt=AU_Motorcycle_Parts_Accessories&hash=item4aa9039c28)
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thanks Mark
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I know that motoplats are not the greatest but I think they are still maligned. All my bikes have them and basically they perform with them. Yes I have had a few problems but then again basket cases still have sparked. Try checking all the earthing to the frame etc, has the timing slipped or the flywheel key gone south. Also check the plug cap and the plug. I run my larger bikes at 30:1 and will try to run my 125s at the highest possible ratio when I get them on the track. Hope you can resurrect the motoplat without forking out for a new ignition, especially one without a flywheel for the 495!!
Bill
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I have had spark problem's on 495 with the stator not properly earthed. It gets all yucky behind it as the cases oxidise, You should check and clean this area if you havent allready.
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Have been informed a new box has been completed to work with the PVL stator ;)
Bill an H Holden might be a good reliable car but a 2010 Commodore will do the same thing,just so much better , same with ignitions.
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I have had spark problem's on 495 with the stator not properly earthed. It gets all yucky behind it as the cases oxidise, You should check and clean this area if you havent allready.
I'm thinking this might be part of the problem.
Not because of corrosion, but because of paint.
My bike has not long been restored and although I removed the powdercoating from the frame where the coil attaches, there's still paint in between the mounting tabs on the frame and the engine cases.
I'm going to run an extra (earth) cable from one of the coil bolts down to the stator plate in an attempt to get around any HR earth dramas, and I'm going to try slightly hotter plugs and only use fresh fuel with synth oil at 50:1.
If this setup proves reliable, I won't worry about an aftermarket system.
I can also get the motoplat repaired if needs be and I'm assured it can be made better than new, so I still have that option as well.
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This is my standard, even with PVL ignitions.
Always run an earth wire from the Coil mount down to the stator backing plate.
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Why not have the original motoplat rebuilt?
I'm a bit on Lozzas team here...the Motoplat was never a great ignition in the first place when compared to even the very early Japanese CDI ignitions. I've had a brand new off the shelf Motoplat last one ride and have spent good money having it and other Motoplats fixed. They work OK but you never know when they're going to fail. I've been using PVL ignitions on my Maicos for over 10 years and have never had one inkling of a problem with them....never touched 'em once I fitted them. It's the same with the CDI ignitions on my Yamahas. I've been using MX250 inner rotor and DT400 outer rotor ignitions on my DT1 based specials since day one of VMX with zero failures. In all of my years of racing the only ignition failures I can recall have been with Motoplat or Femsa.
Now we're in the new millenium, why not use new millenium electronics to keep our old bikes user friendly?
There are some good kits coming out of the UK based on model aeroplane ignition, there are other kits out of Czecho, Slovenia and even China that are infinitely better than a 30 year old Motoplat or even a brand new overpriced PVL. You'll find that these modern ignitions are often cheaper than having your Motoplat rebuilt. You could even modify any number of rock solid Japanese ignitions to the Kato with good results.
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any of the yammie ignitions fit a 1981 KTM, anyone tried it?
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Tossa your KTM is still giving you trouble ? Are you bringing it to CD8? If it really gives you the shits you can sell it to me.
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you are very accomodating but Wa a bit far to take the bike, and yeah it's still giving me the sh*ts
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Well if you come to CD8 I'm sure I can find you a KTM to do a few laps on.
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i would love to have a ride. if i can't start this one soon, going to CD8 might be the only way!!!lol