Spark plugs type & "Carbon Guard" Evinrude 20hp

[Emerald Fox]

Hi Folks, and greetings from Finland (Scandinavia)! Has anyone any advice/comments on these?:
Recently we made two 'epic adventures' here in Finland in our small 5m-long open boat, one of 1? days, the other of 4 days (Kiuruvesi to Kuopio, and Anttola to Savonlinna & back). Before these trips I tried to improve my knowledge of the engine but am just as confused as before...

Spark plugs: when I bought this boat 4 years ago I changed the plugs straight away and was given by a boatyard Champion QL77JC4 plugs (made in Mexico). I asked on iboats and was told the gap should be 0.030 inch or 0.762mm, however a reputable boatyard here in Helsinki told me the gap should be 0.9mm

Now I can't find these plugs anywhere. I was told that NGK B6HS would do (these are without the radio suppressor, but how important is that?) and in fact they did work - I was told also that the gap should be 1.0mm
Another boatyard told me I should have NGK BZ7HS
Yet another boatyard sold me NGK BR7HS - these have the radio suppressor and are obviously the 'same' as B6HS with a different 'heat rating', but is the BR7 better than the BR6 for this engine? I tried the BR7s and they work fine too (also 1.0mm gap).
Engine is Evinrude 20hp BE20SEEUM, built in Belgium in 1997.
So, what plugs should I be using, and what should the gap be?

Second thingy is that OMC recommends that their "Carbon Guard" is added to the fuel always, to keep the pistons clean of gunge, and on boat forums many people swear that they use it (or similar) always. I can't find this in Finland and was more or less laughed at, being told that Finns don't bother with that nonsense, they "just drive!".
I notice however that these shops sell small bottles of a blue liquid "Starbrite Startron" which is supposed to be some kind of miraculous enzyme treatment which keeps the engine insides clean of carbon build-up, and I bought some and added it to the fuel. Is this stuff (a Florida company?) any good, or is it a waste of money?

 

[Emerald Fox]

Re: Spark plugs type & "Carbon Guard" Evinrude 20hp

ps - the B6 plugs are made in france, the BR7 plugs in Japan

 

[spicerak]

Re: Spark plugs type & "Carbon Guard" Evinrude 20hp

You should get the spray and shoot in the carbs for carbon build up and you will see a huge difference. Trust me, get two to tree cans and follow directions.

 

[BaitThrower]

Re: Spark plugs type & "Carbon Guard" Evinrude 20hp

The comparable NGK plug for a QL77JC4 should be a BZ7HS-10. It should be regapped to 0.030".

Regarding the radio supressor... I think it may be important because I switched from Champion to NGK not long ago and the last few times out I seemed to experience a bit of radio interference on my sounder and radio which are all located close to motor on my small dinghy. I can't recall having these same problems when using the Champion plugs so i might go back to them. The reason i switched in the first place is that NGK are muchb easier to find where I am. I have to order in Champion plugs.

But those 1.0mm gap seem way too large. Sounds like one of those boatyards sold you the wrong plugs.

 

[JB]

Re: Spark plugs type & "Carbon Guard" Evinrude 20hp

Boatyards and dealers usually recommend what they have to sell, E. Fox.

Nowhere will you get better advice than here on iboats.

Use the Champion QL77JC4 or L77JC4 gapped at .030" (.762mm).

Good luck.

 

[Emerald Fox]

Re: Spark plugs type & "Carbon Guard" Evinrude 20hp

This morning I measured the gap on the B6HS sparkplugs I had used on our trip Anttola-Savonlinna (engine worked fine) and found it to be about 0.7mm (0.7 blade will go in, 0-8 won't) which is indeed around 0.030"

So, 0.75 is not 1.00mm as the boatyards tell me the gap should be! The gap is as it came, factory-set. Seems this factory-set means the manufacturers know what they are doing, what the gap should be!

So, boatyards in Finland, to my experience, are fairly ignorant and do talk a load of bollocks! Thank goodness for 'iboats' and (?) Americans who have more than 2 brain-cells to rub together

Finland has, however, an amazing network of lakes, if anyone is interested in this you can always contact me at kivikettu@hotmail.com - I have been on the sea between Helsinki & Porvoo, Lake Puula, on the sea between Kokkola and Pietarsaari, Rahja Archipelago, from Mikkeli to Anttola to Siikakoski and Savonlinna (via Puumala and Sulkava), and from Kiuruvesi to Kuopio. Probably nowhere else in the world has such an intricate system of waterways, well-marked and often with 'trip harbours' - maybe a 'laavu' in which to sleep, with a fireplace (for grilling sausages?!). Mosquitos are a real nuisance in Summer, though (disease-free). British guy here, have lived in Helsinki 18 years.

I'm still curious as to the "Carbon Guard" stuff, should I search for this and use it? What about the 'Starbrite' product, is it just advertising fluff or does it really work - does anyone else buy it?!