My New 1975 Montesa Cota 247 (Pics) Hot Starting Problems. It's My First Two Stroke.

[feetupfun]

I didn't see anybody say this yet but on a 2 stroke, yes you should always kick with the throttle at least part open - except when it is cold and you have the enriching circuit on. If you open the throttle, the enriching circuit does not work.

[handmadematt]

I didn't see anybody say this yet but on a 2 stroke, yes you should always kick with the throttle at least part open - except when it is cold and you have the enriching circuit on. If you open the throttle, the enriching circuit does not work.

Fantastic. This is very encouraging and just what I wanted to hear. I've never owned one before I came to this conclusion through trial and error. I think it'll be plain sailing from here on in. Cheers mate.

[chuckindenver]

247 Cotas are known to clog up the muffler, or the mid pipe with oil and carbon,

remove them, clean the nasties, and see how she runs.

[handmadematt]

Tragically I went out for another run today and although I had great fun and the bike performs fantastically I stopped in the middle of the woods somewhere to take off some of my layers, I put the bike in neutral and pressed the kill switch. Thirty seconds later I tried to start her again. NO JOY. It's a real shame. I kicked and kicked until I was worn out, after many in's and out's of the plug, trial and error of different starting procedures she did start as if nothing had happend, randomly on a kick where I was giving it no throttle which goes against my experience yesterday. I then continued a great ride having lots of fun. Upon returning home I killed her with the switch again and couldn't re-start her at all... I returned her to the garage dismayed and not knowing what to do next. The previous owner's been in great email contact and he is just as confused as me. He did say that she's not been ridden much in the past year...

He's said he's never had to start it with the throttle wide open. He also says that he always ran it on normal unleaded (on his new bike he uses Super -high octane) I'm using normal unleaded as well.

(There is air, there is a spark and there is fuel, what's the problem!?? Timing?)

I'm at a loss, it really puts a "spanner in the works" of an otherwise fantastic new bike.

Thanks again for reading. Advice welcome.

[old trials fanatic]

Have you tried disconnecting the kill switch and riding without it? Just a thought i might be that thats causing the problem.

[handmadematt]

Have you tried disconnecting the kill switch and riding without it? Just a thought i might be that thats causing the problem.

Thanks bud.

I've not tried that but every time this has happend I've checked for a good spark on the plug and I always get one so it does lead me to think the ignition side is fine (unless it's the timing?)

[handmadematt]

What about retarding the timing slightly? (Does anyone know any online tutorials to help me with this?)

[big_red_bike]

What about retarding the timing slightly? (Does anyone know any online tutorials to help me with this?)

Hi is there a plastic spacer between the carb and barrell. If not when the engine is hot heat can transfer to the carb making it hard to start.

[westyfield7]

..I can see there being a nice 247 on eBay soon if Matt doesn't get to the bottom of this.

Where would you start.. is it ignition or fuel? maybe both but I would start with the cheapest option of renewing the crankcase oil seals, they may have been damaged when replaced earlier as the previous owner said.

Fuel is obviously flowing freely so the next thing I'd try is the coil.. maybe breaking down under pressure when hot?

[woody]

The fact that it is happening consistently with you operating the kill switch could indicate a possible problem with it - they can and do give problems, particularly cheap versions. I'd replace it as a matter of course. A spark you can see at the plug can get extinguished under cylinder pressure at the speed a kickstart turns the engine if there is a bad connection somewhere. Once a bike is running there is enough power generated to overcome bad connections, so you don't have a problem until you stop it again, or revs drop to almost stall speed.

Genuine Yamaha are very good and around £15

http://www.ebay.co.uk/itm/Yamaha-TZ250-89-99-Kill-Switch-Gen-Yam-New-/400369891579?pt=UK_Motorcycle_Parts&hash=item5d37e7b8fb

or there are patterns a bit cheaper but for the sake of a few quid I'd get genuine.

Timing won't be the cause of the problem and if the bike runs fine when going the timing is likely to be correct anyway. The bike will still start with the timing advanced or retarded. I ran my SWM with the timing on full retard. If the timing was out markedly performance would suffer and it would either pink/knock when hot or suffer from lack of power and have a slow pick up.

I'd begin by looking to the kill button and then check that you don't have any nicks in wire insulation from stator to cool.

I think you're worrying too much about this 2-stroke 4-stroke thing

Nothing to do with starting problems but I'd run it on Shell V-power or equivalent anyway rather than the lower octane stuff. These bikes used to run on 4 star when new.

To adjust the timing you just remove the flywheel and rotate the backplate in the direction of the flywheel rotation in order that the points open nearer TDC. But I really wouldn't bother with this as it is not going to solve your problem.

Consider fitting a decompressor kit too as these can be used to aid starting. Hold the lever in and give the engine 3 or 4 good kicks on full throttle - this puts a charge into the engine without flooding it, then let the lever out and give one good kick which should see it fire u. With practise you can actually use the decompressor on the 'start kick' also as it removes the resistance from compression when first trying to kick it.

[helm]

HI

IS THE CONDENSOR STILL MOUNTED ON YHE COIL, NEXT TO THE POINTS; IF SO THIS COULD BE THE PROBLEM AS THEY ARE PRONE TO OVERHEATING.IF YOU SEARCH THE THREDS THIS HAS COME UP BEFORE;;;

ALSO CHECK THAT THE HEAT SHIELD BETWEEN THE CARB AND BARREL IS FLAT AS AIR LEAKS HERE CAN CAUSE PROBLEMS

FINALLY IF POSSIABLE TRY A DIFFERENT COIL AND CHECK THAT IT IS BOLTED TO BARE METAL FOR GOOD EARTH

CHEERSZ

[handmadematt]

Thanks again for the brainstorming contributions. It's really great.

The fact that it is happening consistently with you operating the kill switch could indicate a possible problem with it - they can and do give problems,

It has happend when I stall the bike as well. Additionally, every time I have checked to see if there's a spark and there always is, it's always a strong blue snappy spark. If the switch was at fault then I would have experienced a scenario with no spark.

Timing won't be the cause of the problem and if the bike runs fine when going the timing is likely to be correct anyway.

This was what I was thinking (about it running well,) and is good to hear. I did think though that poorly set timing can make bikes hard to start.

Consider fitting a decompressor kit too as these can be used to aid starting.

My Royal Enfield's both have these and it does make life easier. Any idea where I can get one?

HI

IS THE CONDENSOR STILL MOUNTED ON YHE COIL, NEXT TO THE POINTS; IF SO THIS COULD BE THE PROBLEM AS THEY ARE PRONE TO OVERHEATING

Good thinking but no, it has already been relocated up under the tank next to the coil for this reason.

FINALLY IF POSSIABLE TRY A DIFFERENT COIL AND CHECK THAT IT IS BOLTED TO BARE METAL FOR GOOD EARTH

The previous owner has fitted a new coil and it is earthed with a wire directly to the engine casing because it's a powder coated frame and he said the earth was a problem before. Maybe I should buy a spare and just see..?

All good thoughts, and thanks again but I'm still completely baffled! My Dad's going to join me in the garage over the Christmas holiday and have a fiddle, he's great with these things. Although at first he said that it's because it's a highly tuned competition bike and it could be normal but I told him it most certainly isn't! As it is it's unusable really, let alone for competition!

[handmadematt]

Hi is there a plastic spacer between the carb and barrell. If not when the engine is hot heat can transfer to the carb making it hard to start.

Yeah, it has one.

..I can see there being a nice 247 on eBay soon if Matt doesn't get to the bottom of this.

HaHa, never!

[handmadematt]

I've been going through all of the ignition to look for faults and it's all perfect. I crocodile clipped the plug to an earth and it would spark really well all the time, every time. Everything was visually inspected and looks great, the coil does look nice and new. I then removed the timing case to have a look in there to make sure it wasn't wet or anything. Looking behind the flywheel I spotted two loose wires with uninsulated ends.. Which is not good practice obviously. Here they are:

I think they must be remnants of the condensor before it was moved up onto the frame with the coil? Maybe they're safe and are not connected to anything but I want to check anyway incase they are causing me a problem.

Comments welcome.

I couldn't remove the flywheel for the life of me though!

It's an opposite thread right? (Clockwise should loosen the nut?) I put the bike in top gear and held the rear brake on but no luck. Is there a trick to this?

Thanks again.

[handmadematt]

UPDATE.

I removed the flywheel holding nut in the end by gently shocking it with a hammer.

However, unfortunately none of my flywheel pulling tools are the right size to screw into the flywheel, they're all too small. Does anyone know any tricks to get it off without? (I've tried shocking it with a rubber mallet.)