If you think hifi is expensive try this !!!!!!

[Audio Al]

One of my fleet of floating vessels has a problem :(

Its a 100hp Yamaha 4 stroke , It has developed a misfire :( rough running :( reluctant to rev up cleanly :(

This is a £11K engine now out of guarantee :(, As a former mechanic I have been through everything and am now down to too two 2 suspect electronics

3 weeks waiting list at 2 local Yam dealers

I asked for the prices of a TPS unit £220.00 and a CDI unit £1155.00 :eek: not asked for the price of the 2 dual outlet coils yet or a crank angle sensor I dread to think what the hourly labour rate is :eek:

The engine has done 19 hours from new :doh::(

Wish me luck :)

[Light Dependant Resistor]

If its a hall effect type distributor they are fussy with the gap between the cam and the sensor.
Any water near them will cause a misfire. I would undo the distributor cap and use a hair dryer for a minute or two
to dry up any moisture, if there was chance that moisture was in there.

As for CDI units these are available as kits at reasonable prices.

[Pigmy Pony]

One of my fleet of floating vessels ( I have 6 ) has a problem :(

Its a 100hp Yamaha 4 stroke , It has developed a misfire :( rough running :( reluctant to rev up cleanly :(

This is a £11K engine now out of guarantee :(, As a former mechanic I have been through everything and am now down to too two 2 suspect electronics

3 weeks waiting list at 2 local Yam dealers

I asked for the prices of a TPS unit £220.00 and a CDI unit £1155.00 :eek: not asked for the price of the 2 dual outlet coils yet or a crank angle sensor I dread to think what the hourly labour rate is :eek:

The engine has done 19 hours from new :doh::(

Wish me luck :)

Do you remember when you were a mechanic, and you had to give the customer a price for the repairs, remember that look on their faces? That's your face that is :D Seriously, I hope you get it sorted without too much pain.

My brother's had one or two boats over the years, and I know that financially hi fi is a piece of piss by comparison.

[Audio Al]

If its a hall effect type distributor they are fussy with the gap between the cam and the sensor.
Any water near them will cause a misfire. I would undo the distributor cap and use a hair dryer for a minute or two
to dry up any moisture, if there was chance that moisture was in there.

As for CDI units these are available as kits at reasonable prices.

Chris , this system does not have a distributor , it has a crank angle sensor , CDI , 2x coil packs , The only CDI unit I can find used is £250

[walpurgis]

Stale fuel in the tank left from last season?

[Light Dependant Resistor]

Chris , this system does not have a distributor , it has a crank angle sensor , CDI , 2x coil packs , The only CDI unit I can find used is £250

So likely to be either a hall effect or optical pick up sensor that needs checking. The CDI common circuit is explained here: https://www.youtube.com/watch?v=0yK3Opq_i0M
We can see the pulse rotor and trigger coil feeds to gate of a SCR ( Silicon controlled Rectifier aka Thyristor )

If you can check in your case the crank angle sensor that it is clear of any debris, which is the equivalent of the pulse rotor and coil in the above video.
There is a CDI kit available locally here: https://www.jaycar.co.nz/high-energy-ignition-kit/p/KC5513 if that might help.

I recall fixing a similar unit for a stranded motorist in remote Western Australia, the fault was a tiny amount of mud on the sensor - as soon as it was cleared
it ran like the proverbial kitten.

[AJSki2fly]

Stale fuel in the tank left from last season?

This is well worth checking and flushing the system through, if low grade fuel with ethanol was left in the system then after 90 days the ethanol will have separated from the petrol and the ethanol will then have absorbed water and chemically related creating a mild acid this, can/wll corrode quite a few components including rubber seals, this crap can get in the injectors etc. I know from experience as our mini Cooper S fuel pump diaphragm was turned in into a soft mess a few years ago and failed.

[spendorman]

"The engine has done 19 hours from new"

Perhaps you're covered under the Consumer Rights Act

[Audio Al]

Stale fuel in the tank left from last season?

No sadly not :(

[Audio Al]

This is well worth checking and flushing the system through, if low grade fuel with ethanol was left in the system then after 90 days the ethanol will have separated from the petrol and the ethanol will then have absorbed water and chemically related creating a mild acid this, can/wll corrode quite a few components including rubber seals, this crap can get in the injectors etc. I know from experience as our mini Cooper S fuel pump diaphragm was turned in into a soft mess a few years ago and failed.


Its a carb model and I have had the carbs off , they are spotless inside as they should be with only 19 hourd use from new , I allways pulled off the fuel pipe and left the engine running until it died , no more fuel left

[Audio Al]

"The engine has done 19 hours from new"

Perhaps you're covered under the Consumer Rights Act


Sadly not :(

[AJSki2fly]

Its a carb model and I have had the carbs off , they are spotless inside as they should be with only 19 hourd use from new , I allways pulled off the fuel pipe and left the engine running until it died , no more fuel left

Ok so not going to be degraded fuel issue.



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[AJSki2fly]

Just had thought would it be possible running it dry to draw crap into one of them and block a jet or cause sticky float? Or is in line filter too good for this to happen


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[Audio Al]

Just had thought would it be possible running it dry to draw crap into one of them and block a jet or cause sticky float? Or is in line filter too good for this to happen


Sent from my iPhone using Tapatalk


2 new fuel tanks not had more than 40 ltrs through each tank , squeaky clean

[walpurgis]

Have you checked the tank vents? Even new ones can be dodgy.

[AJSki2fly]

Yes, I get it, but sometimes it is not obvious, I’ve known the cans used to get the fuel to be knackered and they make fuel dirty, just a thought.

Also I and a friend both had cars breakdown with similar issues, turned out the ESSO station had tanks that were letting water in and had corroded and were full of crap, so when they got near empty crap was pumped as well.

Just trying to help, would be a shame to spend lots only to find out it’s a simple issue.

[Audio Al]

Have you checked the tank vents? Even new ones can be dodgy.

I have run the engine without the filler cap on and its still runs like a bag of bolts :doh:

[Audio Al]

Yes, I get it, but sometimes it is not obvious, I’ve known the cans used to get the fuel to be knackered and they make fuel dirty, just a thought.

Also I and a friend both had cars breakdown with similar issues, turned out the ESSO station had tanks that were letting water in and had corroded and were full of crap, so when they got near empty crap was pumped as well.

Just trying to help, would be a shame to spend lots only to find out it’s a simple issue.

The engine is fitted with a water trap , If it has water in the fuel a red disc floats up , Also I take the 25 ltr tanks to the garage and fill them , I have disposed of one lot of fuel , this lot is only 3 weeks old

[walpurgis]

Shame you're having this kind of aggro Al. I hate modern machinery. Gone are the days when a quick rub of the points with a bit of emery would sort you!

[Audio Al]

Shame you're having this kind of aggro Al. I hate modern machinery. Gone are the days when a quick rub of the points with a bit of emery would sort you!

+100

[alphaGT]

I recall the old saying, “A boat is a hole in the water you throw money into.”

Russell

[Audio Al]

Day one of week 4 and its still at the Yamaha dealers :doh: do they know what they are doing ?????????

[Audio Al]

Well I collected the engine Thursday , Re fitted it Friday ,and connected everything back up again , Control cables , Wiring and fuel line , started it up in a water tank , Started instantly went into fast idle on choke , revs slowly reduced onto tick over , gave it a few revs out of gear and it sounded a lot better than before , dropped it into gear and instantly emptied the water tank with the prop wash . Will be launching the boat next weekend , Anti fouling just before the launch .

Looks like the dealers have sorted it :) , and I didn't :( Oh and the nice dealer man gave me a bill for £340 :eek: plus £15 for 2 engine mounting bolts :eek::eek: he justified the £7.50 each price by saying " They are genuine Yamaha parts " Gulp !!!

[Audio Al]

I recall the old saying, “A boat is a hole in the water you throw money into.”

Russell


Yes Indeed you do , Lots of it ££££££

[walpurgis]

That's good news Al.

[Audio Al]

That's good news Al.

Time will tell when I give it a sea trial , I am hopefull though as it sounded much better ;)

[JohnJo]

Good result Allen.

What was the fault in the end?

Did you get the old bolts back? :D

[Audio Al]

Good result Allen.

What was the fault in the end?

Did you get the old bolts back? :D


The dealers cleaned out the carbs , I already did this and ultrasonically cleaned each carb stripped down into compontent parts , and it made no difference to how the engine run , The carbs were spotlessly clean inside , I was told by the dealers they found salt and corrosion inside the carbs and filters :scratch: work that one out ??? I can't :hmm:

They also fitted new gaskets, O rings and seals to the carbs part of the £340

I had the 2 old bolts they were the lower 2 of the 4 fixings onto the transom , I cut the heads off making it easier to get off without going into the bilge under the floor , However I had the unenviable task when re fitting , It was like caving , good job i'm not claustrophobic :D , I was pleased that OLD boy me was still capable of doing this :)

[JohnJo]

Mmm...sounds a bit strange. At least it's working!

Good for you getting down in there and getting it done, when you've got it you don't loose it!