Mariner 135 service tips needed, no spark one bank

**FORBESAUTO** · 06-22-2018, 11:10 PM

**LakeFever** · 06-23-2018, 08:00 PM

I went to the local merc marine supply today and they were sold out of rectifiers so I decided to see if I could patch up the one I have and I did. The housing was melted a little and the pin was not tight because the melted plastic kept the larger of the two leads from making good, tight contact. I had some brass rivet washers here so I filed the hole large enough to fit over the pin x2 and with a new brass nut got it gutentite. Then the fun started again, or lack of. I had a brutal time trying to start this thing again. I flooded it right away by pushing in the key and pulling up the lever. I had to pull plugs three times, heat the bores with torch and spray quick start and fog a little down the carb bores to start it. Once it fired it idled and ran perfectly well so why I am struggling to start this thing puzzles me. Good news is no more spark on the rectifier so I ordered new online and can wait while I run this one temporary. Also good news I let it warm right up and the tell tale was spraying good and strong. Feeling ready to launch except the damn cold start problems.

What is the ideal starting procedure for one of these? I squeezed bulb ( still tight from yesterday ), lifted idle arm, turned key and pushed in primer. That flooded it. Tomorrow Im thinking to try and crank with no idle arm and no primer. Suggestions? Some mechanical aspect I should investigate?

**FORBESAUTO** · 06-23-2018, 09:54 PM

What spark plugs are in it, and how fresh are they? Seems to be flooding/ fouling plugs way to easy. Compression was good on motor, so next suspect would be just plugs fouling prematurely? I have really good luck with the NGK B9HS10, never have problems with fouling even running pig rich idling around breaking motors in. With the compression near 140 I would use these. Can’t think of a way the primer could be or set up to be overfueling off the top of my hollow head at the moment. If ya haven’t already, try spinning it then push in primer if it don’t fire up. The advanced timing added by raising the idle up lever should actually help prevent flooding.

**FORBESAUTO** · 06-23-2018, 10:11 PM

Unless ya got a leaky fuel pump and it’s flooding it out when you pump the bulb?

**LakeFever** · 06-24-2018, 06:24 AM

Plugs look to be in good shape. NGK BU8H, but new/spare plugs is always wise so I'll dig up some of those B9HS10's and try.

The only thing that leads me away from thinking fuel pump is the bulb holds its prime tight over night so if the fuel pump was passing wouldnt the bulb relax? Any way to test fuel pump? Im thinking of pulling the carbs off today to check float levels and clean further. I did pull the plug/jet out of each carb for inspection and cleaning and they were all clean no gunk or varnish at all so I left the carb set on and moved forward. It could also be my starting routine is fubar, on my OMC I pull idle lever high and push primer in while cranking, once it fires I have to keep intermittently pushing the primer for 30 secs or so til idle catches all while playing with the idle arm so it doesnt over rev cold. Been trying these habits on this motor and have definitely not been working.

Today im going to lift the arm, turn key without pushing key in or priming bulb and see if it catches. Once it lights it purrs along just fine

**FORBESAUTO** · 06-24-2018, 09:50 AM

That’s the correct plugs for ya mota. The 8 is the correct stock heat range and is a step hotter than the 9 which will help prevent fouling. I suggested the 9 because when compression is near 140 I like to go to the colder 9’s. In this instance it’s a good idea to stick with the 8’s until problem is resolved. I feel the plugs with the conventional extended tips (B8HS10 and B9HS10) resist fouling by placing the electrode farther into the chamber more in the heat of things, helping keep it clean. Jmo

**LakeFever** · 06-24-2018, 10:06 AM

I hear ya re the anode free plugs. Only other engine I ever had that rans these was a Kohler in a Merc Trail Twister 440 and they were not the best in that thing either, for fouling especially. I switched to a BR9 and it ran much better. I havent had a chance yet to fire it today because its raining and I dont want to fire it inside because of the water and smoke. I have a gut feeling its a combination of my starting method and that it hasn't run in a while so the carbs might be a little off. I am a little hesitant to pull the carbs off simply because I dont have gaskets and dont want to suffer anymore downtime before trying it out. I may drop it in the lake tomorrow or Tuesday if I can. In my experience with two strokes a lot of times once running a good long run usually clears up any starting gremlins for the season. Im hoping this is also one of those times, plus it does run so well once lit. It sounds like a freakin Nitro engine when its running, I think the heads have been milled already or something it just has that high compression crispy sound to it. My neighbor literally ran over in excitement yesterday he couldnt believe how good it sounded.

Tons of fun so far

**LakeFever** · 06-25-2018, 03:37 PM

I didnt get a chance to mess with it yesterday but just now I tried to start using idle arm up no choke, no bulb prime, and it flooded badly, no start. I wonder if some fresh plugs such as the B8HS10 would help?

**FORBESAUTO** · 06-25-2018, 04:57 PM

Probably wouldn’t hurt before ya get off into the wild goose chase. Pretty cheap to try and look at like part of maintenance.

**LakeFever** · 06-25-2018, 05:44 PM

Cant hurt to have a second set of plugs in the boat anyways. I usually do have a LOT of get ya home parts in my boats, experience taught me to always be prepared on the water.

**LakeFever** · 06-25-2018, 08:15 PM

Picked up a set of BR8HS10's what gap you recommend?

**FORBESAUTO** · 06-25-2018, 09:09 PM

I run 0.035 on the gaps. Agree it’s a good idea to get ya some spares in boat ‘case ya foul one. That way it don’t ruin your outing. Good luck, hope it’s an easy fix. Let’s is know how it turns out.

**LakeFever** · 06-25-2018, 09:20 PM

Thanks again. I may pull the carbs tomorrow and go through them as well while Im at it. I dont think I will have time for launch til later in the week so I might as well dial in everything I can. I'll update as I go

**LakeFever** · 06-26-2018, 09:06 PM

Success!!!!

I pulled the carbs, and right away there was a red flag on the track. Although I had inspected the lines for cracking, I could not see the back side of the little charge lines, and two were split wide open on the back that go to the little valve ( poppet iirc ) and that surely was not helping me at all. I also had a seriously clogged fuel filter ( how this contributed to a flooding condition I have no idea ) so I dug in, pulled the carbs, stripped them down and cleaned them thoroughly. They were very clean to begin with but a couple of the tiny holes in the top were gummed up a bit which Im sure would have cleaned out with some run time on the lake but regardless they are spotless now. I also decided to change every fuel line and oil line on the thing along with a new fuel filter. It was a bit of a chore but fresh is good peace of mind and I tie wrapped the barbs as well. Tossed in the new plugs gapped at 035, squeezed the bulb, hit the key, and vroom she fired right up and purred smooth as butter. Very pleased with how good its running now so we are ready for launch soon as I have time.

Thanks for all the help guys and Forbes especially a huge help man thank you!