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dkarten

Cota 247 Ignition

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I've had my '74 Cota for 22 years, always ran on points & coil, always hard to kick but always started, I'm getting old, recently had starting issues, installed compression release, still no start but had spark, pulled flywheel, checked points  & decided to replace condenser, when I removed old condenser the wire pulled out from center of condenser, so thought that was issue, after 22 years with that condenser, replaced with new condenser & moved to under tank but then completely lost spark, decided to install Electrex ignition after reading on this site that others have done this & have 1 or 2 kick starting.  while it now runs still have very hard starting, timing is set at 27%, new plug, carb is clean, running on non ethanol fuel, any suggestions?

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Hi,i have the Electrex world electronic ignition fitted to my 1977 Montesa Cota trail. Fitting it was fairly simple althogh do make sure the flywheel they supply is lapped to the crankshaft with some valve grinding paste and there is no damage on the end of the crank as the Woodruff key only locates the flywheel in the correct position and the fit of the flywheel is the taper and securing nut. I just nipped up the stator screws and refitted the flywheel and checked the timing marks with the piston at top dead centre(checked with a TDC tool fitted instead of a spark plug to get it accurate) I set mine at 21 degrees before top dead centre and it starts within a couple of kicks and first kick when hot. These Montesas will start at anywhere between 20-27 degrees btdc but the factory setting with points is 21 degrees BTDC so thats what i went with. The spark plug gap needs to be a bit wider than with a points equipped bike. I went with 0.7mm. You need a good earth so make sure the paint or powder coating is scraped off where the coil is fitted and the wire to the frame. Strangely enough you get a slightly stronger spark at low RPM with the original ignition but high RPM and the inbuilt ignition curve on electronic ignition is where the benefit is. Also you will rarely if at all need to remove the flywheel again. When you fit the flywheel nut ensure it is torqued to 72lb/ft although i used an electric impact wrench so may have overdone it a bit! Last point is never assume your new spark plug is a good one,i use NGK or nipon denso. I used a champion plug on a bike once and it was defective out of the box and i went round in circles trying to find the problem and there are some fake NGK plugs on the market too. If the bike has stood a long time without running i would give the carb a good clean as well and it it takes a lot of kicks to start and then produces a lot of white smoke and your gearbox or clutch oil level drops without reason i would suspect the crankshaft oil seals have worn. If you have lost a bit of compression check the valve in the decompressor is not sticking open or your piston rings are not worn. Just work methodically through the list and hopefully you will get your bike to a one kick starter. If you have the Mk 1 Amal carb operate the tickler button a few times,kick the bike once slowly to get a bit of fuel in the cylinder then give the bike a full swing from full compression and hopefully it will start ok.

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Thanks for the lengthy reply, I set timing at 27% because John Haberbosch's website, Rockymountainmontesa. suggests that, he also says the Cota 247 will start & run from 21-27%, I will go back & adjust timing towards 21% & see how it starts, crank seals are recent & I set TDC using a dial indicator in the spark plug hole. Brand new NGK fitted

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I think retarding the timing will fix your problem ...if you find it is running hot that suggests you have gone too far.  Also can't stress enough that you must set plug gap ....out of the box is too big and the spark will fail.

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I set timing at 21% & while still hard starting cold it does fire up after a few kicks, warm starts are much better. I do find a lack of very low RPM power with the Moterex ignition installed & wonder if I should try refurbishing the original ignition?

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On 12/6/2020 at 5:50 PM, dkarten said:

I set timing at 21% & while still hard starting cold it does fire up after a few kicks, warm starts are much better. I do find a lack of very low RPM power with the Moterex ignition installed & wonder if I should try refurbishing the original ignition?

That is very often the trade off with electronic ignition. Easier starting,better ignition advance curve but a loss of power and rougher running at really low RPM. I was quite happy with this trade off to get rid of the points and condensor.

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Started the 247 for 1st time after winter & started relatively easy & ran great, rode it 2 more times no problems,  yesterday went for short ride, stalled it & won't restart, cleaned plug & checked spark & no spark, checked plug on another bike & shows spark AND tried new plug in Montesa, no spark, so today pulled flywheel thinking the key must have sheared but no issue there, all looks OK, disconnected kill switch & still no spark, Electrex Ignition is barely 6 months old? WTF??

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Edited by dkarten

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I'm posting this followup in case anybody else has similar issue:

I contacted Electrex & Bob helped me diagnose the issue, seems I got a defective CDI (coil) he authorized a warranty replacement & Speed & Sport sent out replacement same day, once installed Montesa starts 1st or 2nd kick after priming with decompression lever, I just happened to get a bad unit, thanks to Electrex & Speed & Sport for taking care of me, bike is a pleasure to start & ride again!

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