New NGK BR8HS plugs improve overall performance

[WinnerCougar74]

I just got back from a few hours on the water with my 1974 Chrysler 135hp. I have had it for 2 years. Today the motor ran the best it ever has. Started right up, Smooth, strong, plenty of power all the way of to 5200rpms and it idled with no trouble @ 800 rpms. I cruised for about 30 minutes @ 4000 rpms. The difference, new spark plugs. I removed the "no gap" plugs (NGK BHW) and replaced them with NGK BR8HS. I think my problems with the motor had to do with the "no gap" plugs fouling to easily. The engine would be idling along and then do the lean sneeze thing. Also it would lean sneeze sometimes when I would start it causing it to take 2 times to start it. Time will tell but so far I really like these plugs. The motor is 45 years old with the original power pack. It might be a little weak so these plugs don't need as much power. Might be interesting to get some opinions on this subject.

 

[Sea Rider]

According to my own experience with such spark plug type is that if you don't run the motor at constant 3/4 to full throttle operation will end fouling the plugs. These plugs are not intended for long trolling purposes as will never self clean themselves which happens above 500 C...

Happy Boating

 

[jerryjerry05]

Some motors can use any brand.
Some just don't run right when you use
NGK and others Champion??
I've had 2 88/85's that it didn't matter the plug??

 

[puffitu]

Great post! I just ordered. What do you have them gapped at?

 

[WinnerCougar74]

Great post! I just ordered. What do you have them gapped at?

Sparkplug gap .030. I have read that the gap on the points isn't as important with these motors. The points are just a trigger for the Magnapower units. So dwell isn't even a thing. I set mine to .010. Changing the point gap just changed the timing a little. Also I have a spin on fuel filter that I added just to keep the old engine as clean as possible. One of the added benefits is you can do a real easy carb flush with it. You just fill up the filter with Seafoam and screw the filter back on. Then pump up the bulb and let it sit. This pushes the Seafoam into the carb and starts to work cleaning things out. Then go run the motor for 15 minutes or more. So easy. I'm gonna do this twice a year now it worked so well and was easy. Don't order the spin on fuel filter with the plastic catch basin at the bottom. I've had 3 of them and they all leaked. I think they ruined my splash well gel coat. grrr Best advise I got on this site was, if the motor idles and runs good just leave it alone. Run it. I tend to constantly tweak things but I'm happy to just run this instead. It's a relief. Plus I'm building up a stock of new parts just in case. Impellers, fuel pumps, gaskets, distributor parts, etc. So I should be good to go for awhile.

 

[puffitu]

Great post! Thanks so much. Would like to know which spin on filter model you finally settled on-(sorry mods)??

 

[dingbat]

Don't order the spin on fuel filter with the plastic catch basin at the bottom. I've had 3 of them and they all leaked.

What brand are you using?
Never had one leak

 

[puffitu]

I just use the quicksilver basic fuel-water separator w/no clear basin but would consider going for the clear view spin on type but read many posts that they leak

 

[dingbat]

I just use the quicksilver basic fuel-water separator w/no clear basin but would consider going for the clear view spin on type but read many posts that they leak

Been using the Racor clear bottom filters on my personal boats as well as commercial applications for many years. None have ever leaked.
Either the filters in question are inferior or people are trying to adapt filter’s components between brands which by design doesn’t work

 

[puffitu]

Been using the Racor clear bottom filters on my personal boats as well as commercial applications for many years. None have ever leaked.
Either the filters in question are inferior or people are trying to adapt filter’s components between brands which by design doesn’t work

So before being asked to start my own thread by the mods; which is good for my application; 88 force 125hp outboard?

 

[WinnerCougar74]

So before being asked to start my own thread by the mods; which is good for my application; 88 force 125hp outboard?

I tried two brands named DLP and AA Ignition. Both had the 2 part filter with the clear plastic bottom. The clear plastic got soft and would not hold it's shape so it started to leak. Then the threads got soft and it would not stay screwed it. Only good thing was the housing and fittings so I bought a Quicksilver 35-802893Q01 spin on filter. I learned my lesson. You gotta pay for the good stuff.

 

[WinnerCougar74]

The Racor's fuel filter assemblies start at about $100 in iboats.com

 

[jerryjerry05]

If the bowl melted??? then you probably had one for diesel fuel??
Maybe the fuel additives caused it?
I get the small one from Sierra and it works great.
Over time they get hard to see through or the drain seal goes bad
and the bowl gets replaced.$16
They're small enough to put almost anyplace.

 

[WinnerCougar74]

Update on the NGK BR8HS plugs. I dodged a bullet. While running back to the dock (about a 15 minute run) and running at 4300rpm the engine started running badly. I decided to go the rest of the way with my kicker so I didn't ruin anything. I found one plug with a smashed electrode on #3 cylinder. Amazingly the piston and cylinder were fine. Only a little metal debris on the plug. Good compression on all cylinders (135psi +/-2). So I switched back to surface gap plugs and now it's fine. It doesn't start as easily cold or hot and idles ruff but throttle response is fine and its smooth starting at about 1/4 to full throttle. Performance is good. Top speed is identical. Also cylinder head temperature is good (135 degrees on all) I am running a new thermostat. All I can think of is it was running a little lean maybe and a hot electrode on the standard bent electrode spark plugs caused detonation and that smashed the spark plug electrode. Like I said I dodged a bullet. I will not be going back to bent electrode plugs ever. I guess I will live with the starting and idling issues. I am trying a Champion L20V instead of the NGK BUHX. Specs say the L20V is 1 step hotter than the UL18V. The shop manual says to use L20V with magnapower 1 and UL18V with magnapower 2

 

[puffitu]

Thanks for this; been following this thread. I even bought a bent electrode set but they just sit in n the box. Good to know-thank you!

 

[WinnerCougar74]

Some with the conventional ignition conversion say they run the bent electrode with no problem. I wish I could. I loved how they idled. Well we will see if the L20V's do any better. I triple checked and the L20V is definitely referenced in the shop manual for my motor. Here is a link to the manual.

CHRYSLER 75 H.P. SERVICE MANUAL Pdf Download

View and Download Chrysler 75 H.P. service manual online. Three and four cylinder outboard motors. 75 H.P. outboard motor pdf manual download. Also for: 70 h.p., 105 h.p., 115 h.p., 80 h.p., 120 h.p., 130h.p., 135 h.p., 150 h.p., 85 h.p., 90 h.p..

www.manualslib.com

 

[puffitu]

Some with the conventional ignition conversion say they run the bent electrode with no problem. I wish I could. I loved how they idled. Well we will see if the L20V's do any better. I triple checked and the L20V is definitely referenced in the shop manual for my motor. Here is a link to the manual.

CHRYSLER 75 H.P. SERVICE MANUAL Pdf Download

View and Download Chrysler 75 H.P. service manual online. Three and four cylinder outboard motors. 75 H.P. outboard motor pdf manual download. Also for: 70 h.p., 105 h.p., 115 h.p., 80 h.p., 120 h.p., 130h.p., 135 h.p., 150 h.p., 85 h.p., 90 h.p..

www.manualslib.com

Yeah well I’m running around with a 125hp and pretty happy with the no gappers; idles perfect and has great hole shot. Just a slight case of hick ups at start up but clears up in 10 seconds as it warms up. I think I’ll leave well enough alone on this one for now

 

[jerryjerry05]

I ran my twin 88/85hp with Champion, NGK and Autolite
The Autolite didn't seem to last the Champion would last forever if I left them in. Changed them mostly out of guilt, thinking I should change them every year or 2
One time I let them go for 5+ years and when replaced they were still in great shape.
Never saw any difference between the NGK and Champions.

 

[WinnerCougar74]

Puffitu, If I can get my 135hp to run like yours I won't mess with it anymore.

 

[WinnerCougar74]

I thought some of you might enjoy some pics

Here is the spark plug that got smashed.