Outboard problems

[jwalker]

So Jiz, what was the final outcome?

JW.

[Jizm]

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!!!
Regards
Jiz
To quote the missus:' get it back and get a manual!!'

[thewavehumper]

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

[Jizm]

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.

[jwalker]

To quote the missus:' get it back and get a manual!!'

Good advice.

JW.

[jwalker]

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.

JW.

[jwalker]

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.

[Jelly]

JW
Thanks for that, learnt something today!!
If I had known that a few years ago would have saved the cost a CDI.
Jelly

[Jizm]

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.
regards
Jiz

[thewavehumper]

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

[Jizm]

well without boring you all to death.........
I got my RIB back today after just turning up and getting it. The guy never did phone me. He is still saying it's the CDi even though it went ok on a sea trial but played up on the trailer upon return. I have just run it up in the garden and there is no problem, so I am still none the wiser! I left the boat yard about a hundred quid lighter having been without the RIB for over three weeks and on top of that it's still not repaired! Valuable lesson learned.
I am taking it out tommorrow for a sea trial myself and I will keep you all posted as to how it goes. I have a guy in the states trying to sort a CDi for me if required (£100 compared to £300+vat here) and would just like to take this oppurtunity to thank everyone who answered this post, all replies have been very helpful. The saga continues...........
regards
Jizm

[jwalker]

Jiz, if it's variable as you say, it's more likely a connection problem. Pull apart all the ignition connectors, one at a time, check them and replace them. Especially check the ones coming down from under the flywheel and the main ground at the CDI unit.
JW.

[Jelly]

Jizm
looks like my previous got lost, if you've got a late 80's yam my manual minght cover it, give ma a call on 07970163580 if you want to borrow it.
Jelly

[Jizm]

Thanks JW, that was my thinking and my next port of call. I have run the motor about 20 times since wednesday ,at all different operating temperatures, and the fault did not rear it's ugly head again. Have not had a chance to test it under load yet though so I'm not convinced.

Jelly, My motor is 1993 (the only useful info from the "outboard technician!!!"). I have ordered the relevant manual from amazon as they have just reduced most of the Seloc and Clymer manuals by about 30%. Thanks very much for your offer though, it is much appreciated.
regards
Jiz

[Jonny Fuller]

Don't know about the yams, but the merc's can suffer with the flexi wires from switch box (Ign pack) to trigger (bit that rotates under flywheel when opening/closing throttle to advance/retard timing) breaking down when they get a bit long in the tooth, the wires get wiggled every time you operate the throttle, so eventually the strands break up. this may only show up when using enough throttle to give em wiggle!

just a thought.

[jwalker]

Yeh, I agree. After eliminating all the obvious, start looking for broken things. If a wire has a broken core, you can usually tell by flexing it. It will often adopt a tighter bend at the damaged part.

Jiz, we're working a bit in the dark. Would you like to describe exactly the symtoms?

JW.

[Jizm]

Basically I took it out about a month ago and the engine would not rev past 2800rpm no matter what! loaded/unloaded etc. I did plugs and fuel etc before giving it to a guy........ (another story). The motor sounded as if it was misfiring or running on two cylinders (it's a triple) but no matter what I did the motor would not rev past 2800rpm whether in gear or in neutral.
regards
Jiz

[jwalker]

Jiz, What was the final outcome of this saga?

It's the ending which educates us.


JW.

[Jizm]

Well.....
I purchased a manual. Read and digested all relevant chapters cover to cover (fuel ,ignition, electrical etc). I then referred back to the posts in this thread, identified my engine from it's wiring schematic and began metering out coils, crank position sensors etc. Whilst doing this I found quite a few furred up crimp connectors around the CDi / coil area which I re-made/cleaned and lubricated. I then continued checking all connections and sorted them as necessary. Unfortunately the fault was not present at this time ( it had mysteriously gone away!) so I was not sure if what I was doing was helping or not but knew it couldn't hurt. All coils etc metered as per manual specified values, all found OK and within resistance tolerance.
Then I found the PINK wire. This wire was not connected at all but was a male crimp which could easily come into contact with everything in it's vicinity. I identified this wire as the alarm wire for the overheat/over-rev and low oil buzzer in the remote. Earthing of this wire also operates the REV LIMITER in the CDi unit to about 2000-2500rpm!! So although the fault was not present I can only assume that this wire was earthing out due to not being insulated and activating the rev limit. It wasn't sounding the buzzer because the previous owner (or remote installer) had only connected the overheat sensor to the remote unit and not bothered connecting in the oil sensor output etc ( a collection of pink wires with spare female crimps attached!). I followed the schematic, joining all available pink wires together and also linking in the green/red wire from the oil tank ( as shown in wiring diag). I have since run the engine in a test tank and had a sea trial, with (touch wood) no problem at all, in fact the engine seems to start much more easily and sound better than before. I am assuming the fault was indeed down to dodgy wiring and lack of maintenance on the connections. So let me take the chance to thank every one for their help and the moral of the story is don't be naive enough to pay some fool to do something that you are perfectly capable of yourself with a little patience , a manual and some advice from the members of RIBNET much can be achieved. I have also bought an old blown up yam 70hp to strip down to learn even more about the internals of outboards and from now on will be doing my own servicing aswell. Sorry about the length of reply, got carried away!
Thankyou all
Jizm

[thewavehumper]

Cool. good fix see you on the water!