[Eric Yeoman Posts: 740 Status: Offline]

so dipped a piece of cardboard in the fuel tank and tried lighting it with a lighter.

How loud was the bang???   

[Al Posts: 908 Status: Offline WWW]

Nice weather today, so thought I would refit the coils after removing them and cleaning them up and giving a few coats of PCB lacquer.  I refitted them with a 0.011" air gap between coil & flywheel magnet.  engine does not want to fire.  I've checked to see if it's sparking and both plugs have a bright yellow spark.

I thought perhaps the fuel is going stale, so dipped a piece of cardboard in the fuel tank and tried lighting it with a lighter, fuel lit instantly, so thinking fuel OK.




I have the coils on the correct way  "learned that lesson the hard way many years ago". 

I've squirted easy start into the air filter and still not firing.

The battery spins it over for a few seconds then dies, so battery now on charge.

There is no electric wire going to the carb solenoid, so assume that it has been disabled, but perhaps, that should be my next port of call.


Not sure what to try next?


 

[Al Posts: 908 Status: Offline WWW]

I've ordered a pair from Amazon


I couldn't find any that fit the Vanguard 35hp at that price, but plenty at around £12 to £15 for smaller size B&S engines.  I ended up paying just shy of £42 including delivery for a pair of the 845126 coils, which according to the parts list for my engine number are the correct ones.


Briggs Bits are probably supplying genuine B&S parts, hence higher prices

[Nick Flint Posts: 4957 Status: Offline]

I bought from Briggs bits and im well sure I payed way more than that. Are Briggs bits expensive suppliers then?
Which firm are those costings from please Steve?

[Al Posts: 908 Status: Offline WWW]

"You need two kill switches if you remove the diode"
Hi, where do the diodes live? Piccie? 



The diode can be seen here just behind the red heat shrink in the clear sleeve


https://hoverclub.org.uk/index.php?action=dlattach;topic=8202.0;attach=12738;image

[Steve Holland Posts: 1608 Status: Offline]

The diodes are usually in the connection wire between the coils, hard to spot, a small swelling in the wire.
It's possible a dual pole to earth type switch could work, you'd only have one physical toggle to use, personally I find the two switch set up easy and it was useful when I had the vanguard engine that used to eat coils, the intek engine is still on the original coils, I do get spark plug failure occasionally, the dual earths help find the faulty plug quickly.

[Eric Yeoman Posts: 740 Status: Offline]

 "You need two kill switches if you remove the diode"
Hi, where do the diodes live? Piccie? 

[Steve Holland Posts: 1608 Status: Offline]

The coil part number in the attachment comes up for Briggs 35hp.

[Al Posts: 908 Status: Offline WWW]

Ive rejigged the video youtube to remove the {{[{ etc and the link now works to Youtube. I can't see water but I CAN see rust. I would use Corrosion X (especially grease on some new coils and PU of new leads. Replace multi connectors with heat shrunk glued crimped connections would be MY approach, to help towards a  reliable Marinised craft?
Other approaches are available!

Someone had taken the other approach and it didn't work put too well 


I just need to find a supplier of the coils.  Other bits are ordered and making their way to me.  Hopefully the weather stays settled over the next week or two, so I can get this craft sorted, as on annual leave for a couple of weeks come Friday morning 

[Nick Flint Posts: 4957 Status: Offline]

Ive rejigged the video youtube to remove the {{[{ etc and the link now works to Youtube. I can't see water but I CAN see rust. I would use Corrosion X (especially grease on some new coils and PU of new leads. Replace multi connectors with heat shrunk glued crimped connections would be MY approach, to help towards a  reliable Marinised craft?
Other approaches are available!

[Steve Holland Posts: 1608 Status: Offline]

The copy coils are cheap and have less bits sticking out to corrode and trap water, I'll send numbers when I get home unless someone else gives you the information before that.
I don't use diodes in my craft, I think I'm alone in that,if they fail you may lose a cylinder, they apear fairly reliable though so it's unlikely to be a problem.
You need two kill switches if you remove the diode, having two switches does help find a dead cylinder quickly, otherwise more of a fiddle although I'm used to it so not a problem.

[Al Posts: 908 Status: Offline WWW]

Some of the pictures

[Al Posts: 908 Status: Offline WWW]

Here's a video of it running and if you look closely you can see water flowing into the starboard side coil.  The engine cover was removed to gain access to the coils


https://youtube.com/shorts/LFok9CO5Pcw?

[Al Posts: 908 Status: Offline WWW]

When I took the Marlin out for a test flight quite a few weeks ago, pilot error getting over the hump caused some spray and a nasty misfire.  I managed to keep it running and after a few minutes it dried out and ran perfectly again, but knowing that it has not or has been very poorly marinized I didn't risk taking it back out on the water.  Prior to me buying the Marlin it had only had about 4 hours of use on grass and had never been out on the water.


Anyway it has been sat outside my house for the past few weeks & every now and then I would try starting it and eventually it would start, but would take a long time, so I suspected moisture was probably the cause, as it wouldn't make any difference if I sprayed some easy start into the air filter.  Once it did start and run for a few minutes it starts perfectly, so again seems to be pointing at a moisture problem.


There was a few bits I wasn't happy with, main one was air filter being mounted so close to the floor, so I relocated that to be above the engine but facing fore & aft rather than the original B&S way of side to side.  Anyway today I decided to have a look at why it doesn't like starting.  Coils have had no attempt at being marinized, electrical plugs have just had silicon put in the ends, which is starting to lift away.


I don't want to bad mouth the manufacturer, but I will say their marinization on this craft was not very good to put it politely.


I checked the spark plugs and one was firing and one wasn't, I swapped the plugs over and then the one that wasn't firing was and vice versa.  so that suggests a possible coil problem.  I manged to get the engine started and noticed water streaming off the top of the engine and running straight on to the port side coil "that's not going to help matters.


So next plan of action is buy new plugs, coils, (so I have spares), a decent water separating fuel filter, as used on diesel vehicles.  Marinize the engine electrics properly.  Fit another two drain plugs at the rear of the hull near the engine, as no drain plugs fitted that end of the tub.  Fit a bilge pump under the centre tunnel as it fills up with water due to it running down the steering shaft.  Drill some 2 inch holes in the bottom of the rear plenum to aid water to escape if the bilge pump fitted in the plenum fails.


I seem to remember that the diodes fitted in the coil wires could cause some problems, but I can't remember what they were.  Is it a good idea to remove the diodes or leave them fitted?  When removed I seem to remember that the engine would run on or misfire after being switched off.  Info and advise greatly received on this 


Also, where can I buy replacement coils for a Vanguard 35hp? 


I will upload some pictures shortly of what issues I have found so far.