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Old 10 June 2003, 20:30   #21
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So Jiz, what was the final outcome?

JW.
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Old 12 June 2003, 14:26   #22
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The saga continues....

Glad you asked me that. After two weeks down at the workshop it would appear that it is no further forward. Went down on tuesday afternoon to acquire the part no of the cdi unit so as to source one from the states (much cheaper). To my surprise the guy said they ran the engine prior to trying a cdi unit from another engine and it ran sweet as a nut all through the rev range, the problem seemed to have dis-appeared. He said he would try it again on wednesday and let me know the outcome, Thursday now and I have heard nothing! Any way I am starting to lose my faith a little bit , two weeks and still ribless. If any one out there has any more ideas please let me know as I am getting severe withdrawal symptoms!!!
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Jiz
To quote the missus:' get it back and get a manual!!'
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Old 12 June 2003, 17:13   #23
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If your symptoms get too bad you can take my Avon out for a spin over the weekend. just pay for the fuel you use
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Old 12 June 2003, 18:04   #24
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Thanks for the offer Stuart, very decent of you. I think I can survive another few days yet, borrowing a friends horrible jetski thingy over the weekend so should be ok.
You being a local man may know then workshop where my RIB is, a small outfit behind the Riverside chinese restaurant, opposite Sealine on the hamble, 'Bursledon Outboards'. have you or anyone else for that matter had any dealings with them? The guy that runs the show ,Steve I think seems very genuine and helpful but as I said I am starting to lose a little faith now.
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Old 12 June 2003, 19:14   #25
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To quote the missus:' get it back and get a manual!!'

Good advice.

JW.
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Old 12 June 2003, 19:34   #26
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If the engine was just run up to speed, without it being loaded, then the test is not valid or conclusive. A low voltage spark will manage to ignite the mixure because the combustion chamber pressures are still (relatively) low when there is no additional load on the engine. This is because the throttle will not need to be far open to achieve the high revs under no load conditions and, therefore, there is little pressure build up in the combustion chambers. I'd put a penny to a pound that the problem is ignition. I still would check the high speed charge coils. They charge the capacitor(s) in the CDI unit. I don't know how handy you are, but a proper manual will tell you where to connect a meter to measure the output from these coils. A normal voltmeter on its own is not satisfactory. You need to be able to assemble a wee circuit. It's dead easy, just a capacitor and a resistor. The coil voltage pumps up the capacitor and the voltmeter measures this charge voltage. This value will be given in the manual.

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Old 12 June 2003, 20:12   #27
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I was going to leave it there but I thought that a knowledge of the ignition principle might be useful. If you know this already, then just ignore me.

The charge coils are under the flywheel. They charge up the capacitors in the CDI unit. Also under the flywheel are trigger coils. Their job is to fire an SCR in the CDI unit to release the capacitor charge into the ignition coil(s). The ignition coils step up the voltage sufficiently to anable the current to jump the spark plug gap when the combustion chamber pressure is high. The setting of the trigger coils controls the ignition timing. They are mobile to allow the advancment of the timing according to the engine's characteristics.
In modern engines, the timing can be adjusted electronically.

In all the motors I've used, there are low speed and high speed charge coils. The low speed ones have lots of turns on the windings and produce a high output at low revs. But, their characteristics are self limiting as the revs rise so a second coil takes over as the motor speeds up.

If the high speed coil(s) are faulty, the motor will begin to accelerate normally using the low speed coils then it just breaks down at the cross over and the engine stops firing. Of course, as it stops firing, it slows down and the low speed coils take over again. So it is almost as though you have a rev limiter. Which, of course, you have.

Does this sound about right?

JW.
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Old 13 June 2003, 03:49   #28
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JW
Thanks for that, learnt something today!!
If I had known that a few years ago would have saved the cost a CDI.
Jelly
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Old 13 June 2003, 17:20   #29
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Thanks for that JW, very useful info. Definitely going to retrieve my RIB and get a manual at the weekend. Will let you know how I get on.
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Jiz
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Old 13 June 2003, 18:30   #30
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I have used Steve and hes a good guy and I was very pleased with the quality of his work but upset that a service agreed at 180 plus parts equalled 350 and was actioned without discussing the uplift with me. I am Welsh and we to go much for price hikes.

What really hacked me off was that my outboard had a faulty starter motor which was covered under warranty and I never got it, I don't think I was ripped off I just don't think Steve pushed Barrus enough.

I have to be honest and say that I like Lee Fairweathers place (especially the smell) and Whiteshoes says good things about MB marine both of whom arein Fareham creek. I think Lee sells manuals, check his website. Ron Hales in Portsmouth know Yamahas well.

I wouldn't go to the Ribsupercentre at Ocean Quay cos the Yamaha Guy there (Fred) is really a CORGI engineer (no not the Toys) who was sent on a course at Yamaha about 4 months ago.

I have been told in the past that Mobile mechanics are very good guys to use because most of thier business is by word of mouth so they care to be good.

Storm's place is good also but I don't think they do Yammies, Although if I was you put in a carrier bag and catch the train up to Scotland and start promising beer to JW

You could also go the other way and take it to Andy Clarke Bosuns Mate
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