Bogging down/ rough running problem

The 3 1/2 forum
Matt Hale
Posts: 75
Joined: 08 Oct 2020 10:00
Location: London

Re: Bogging down/ rough running problem

Post by Matt Hale »

Many thanks Mark and Bill. I’m currently awaiting news on my red pickup- being checked out for me on another bike.
Could you say if my new blue transducers should work with the red pickup? Does it need the diodes added also as with the black? If yes then this probably my issue. My black transducers produce such a weak spark they are effectively useless. Bike starts so easily with the blue ones…
Thanks for the contact email for Alex L. I have been in touch previously and will again once my pickup is checked.
Many thanks again for all your kind time explaining.
Best to all - Matt
350 Sport 1979 electric start model (missing)
Curry yellow tank etc paint work, navy blue frame, silver wheels.
morini_tom
Posts: 920
Joined: 05 May 2006 13:47
Location: Northampton

Re: Bogging down/ rough running problem

Post by morini_tom »

I’ve been running blue transducers with red pickup on my k1 for a while now and am happy with the way it runs. No need for the extra diode on the red pickup.

As discussed elsewhere in the forum and on Soren’s YouTube videos, you need to adjust the pickup timing to achieve the correct full andvance ignition timing. For me that meant rotating the pickup anti-clockwise as in the photo.

So long as the max advance is correct I don’t worry about where it is at idle- the Morini advances quite early, and so it’s hard to know what idle advance is actually expected. But so long as it starts easily (which mine does, very) then it’ll be ok.

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Matt Hale
Posts: 75
Joined: 08 Oct 2020 10:00
Location: London

Re: Bogging down/ rough running problem

Post by Matt Hale »

Thanks Tom- good to read you post and that red pickup works with blue transducers. I tried putting my red pickup in same position as yours but no joy. I'll know if my red pickup is faulty next week and in a way I hope it is as that will explain my problems. But now I know I can use it if I get it fixed or use a black one with diodes in each red lead to the transducer if I can't get it fixed. Many thanks again you and all!
Safe riding - Matt
350 Sport 1979 electric start model (missing)
Curry yellow tank etc paint work, navy blue frame, silver wheels.
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GHF
Posts: 9
Joined: 13 Aug 2019 15:52
Location: Ashford

Re: Bogging down/ rough running problem

Post by GHF »

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Hi hopefully the picture comes out. I have been having all these issues. Changed needles, atomisers and pilot jets (45).
The pilot jet made a small ldifference. With it getting worse I cleaned the carbs and the pull away judder and lack of power was worse. Cleaned the clutch and adjusted floats to 12.5mm maybe a bit better but when warmed up fully was just as bad. Took out the atomisers and compared them to the old ones. Visually you could see that the bit that sticks into the Venturi was slightly longer on the old one ( doesn’t show well on photo ) , also the hole at the top was different ( measured with a drill bit) and the centre bore felt slightly smaller on the old atomiser.( tested by rocking a drill bit in the bore )
Put the old ones back in and when warmed up fully, completely different bike. Smooth pull away no juddering. No loss of power on pull away, however did feel a little bit less powerful in the midrange. Good idle though!
This worked for me, not sure if you have changed or still have the original parts to swap back but it may help some else.
45 pilot jet
112 main jet
Standard needle top slot for clip
260k atomisers ( old ones )
Float level 12.5 mm to centre
Blue ignition packs with timing set to compensate.
Regards Gordon
norbert
Posts: 750
Joined: 15 May 2007 15:15
Location: Lübeck/Germany

Re: Bogging down/ rough running problem

Post by norbert »

I guess the atomizer is not entering more in the venturi zone, but the rest of the atomizer will be a bit lower.

That reminds me of a sugestion many years ago:
A friend told me that the problem of the mid range, the famous leak of power about 5000, get´s better by putting a small 1-1,5 mm washer underneath the atomizer (means first the washer then srew in in the atomizer). I guess you have to make this washer your own, but obviously that can change a lot!
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GHF
Posts: 9
Joined: 13 Aug 2019 15:52
Location: Ashford

Re: Bogging down/ rough running problem

Post by GHF »

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An update on atomiser. In the interest of science and I fancied a ride i took the bike out for about 15 miles. Bit of town bit of 60 mph roads. The photo is of the spark plug colour. It was sooty before ( I didn’t bother cleaning it ) so it has burnt it all off. It is significantly improved, no misfire/splutter/judder when pulling away. When on constant mid throttle then opening for overtake no hesitation. There is a noticeable dip in power when on 3/4 throttle, nothing drastic just noticeable, but as I said the needle is on the top clip position and the float is at 12.5 mm. Maybe worth a tweek…..later.
Gordon
Matt Hale
Posts: 75
Joined: 08 Oct 2020 10:00
Location: London

Re: Bogging down/ rough running problem

Post by Matt Hale »

I’m very grateful for these replies. I’ve been ‘off’ the bike for 2 months but now spring is anlmost here I’m beginning to get back to it…I’ll have a look at my atomisers. Original ones still in but needle position not in top notch position so will try moving to see what happens. Also I will try the washer addition.
Many thanks again
Matt
350 Sport 1979 electric start model (missing)
Curry yellow tank etc paint work, navy blue frame, silver wheels.
3potjohn
Posts: 1243
Joined: 02 Jun 2007 13:58
Location: Devon

Re: Bogging down/ rough running problem

Post by 3potjohn »

I have had a 350 K1 for a bit ( 16 years in fact) which had 2 different atomisers.I replaced them at the time with the correct 260BD. The carbs have had new slides and needles and O rings.It has a black pickup / grey transducers and standard airbox. Apart from reducing the pilot jets a little to eliminate slight bogging off idle, it has always run well. A failed transducer immediately killed ignition on one cylinder. Failing choke piston sealing eventually began to impact running but easily sorted.
On another bike, a 507 I have had poor mid range especially at a steady throttle. Acceleration was fine.This has Kokusan ignition so not comparable, nevertheless it is a bit of a fright spares wise.
I even tried to check if there was an ignition misfire by fixing a cheap neon strobe to the bars and riding in a dark wooded area with each plug connected in turn. When I hit the stuttering level I thought I out to see some evidence in the pulses. Nothing detected. A bit of an eccentric method perhaps.
This brought me back to carbs. I now have an impressive selection of floats,needles, 264 atomisers and pilot jets. I even got into modifying my own atomisers. From this I also found that there were slight differences between the quoted spec and actual, depending on the supplier.( not exclusively Eurocarb) In the last year I have discovered ,or better still rediscovered, that by putting the airbox back to standard ( it wasn’t) all my issues are resolved at a stroke. Or is that a four stroke? It only took 2 years. Better than watching TV though.
Your earlier video did show an advance issue. Has that been resolved yet? No tight rocker clearances? Standard airbox? No airleaks at manifolds? You will get that Eureka moment soon.
John
Matt Hale
Posts: 75
Joined: 08 Oct 2020 10:00
Location: London

Re: Bogging down/ rough running problem

Post by Matt Hale »

Hi All on this thread + my 'Jetting issue' thread
George Lane has discovered my spark coil was about half the size it should be so rewound it the correct size and my bike starts fine now!! Thank you George and also to all of you here who discussed what my non starting+ problems might be. The coil had been rewound by West Country Windings early on when the bike wouldn't start/run reliably but they had reduced the size. They said it was made to a specification they used to fix them for NLM but.. In fact when I rang WCW for a refund, which I wasn't given, they sad they don't want to do any Morini coils in future! (Not because I was rude as I wasn't!). Best Matt
350 Sport 1979 electric start model (missing)
Curry yellow tank etc paint work, navy blue frame, silver wheels.
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