Mariner 135 service tips needed, no spark one bank

[nitro_rat]

Ditch oil injection on these Mercs too? I know all about the VRO nightmare is this a similar issue?

Unless you tear into the block to do other mods get the oil pump blockoff kit from merc. It has a stem on it wheich retains a bushing inside the block which can fall out otherwise. If you do tear down, leave the plastic drive gear on the crank as it takes up volume in the crankcase. If you have it down that far you can fill the void machined for the oil pump with epoxy (marine tex) to equalze the cylinder volume with the others.

[LakeFever]

New switch boxes arrived and I installed them and voila, spark on both banks. I pour in some new gas, hook up the water supply, crank and NO FIRE. Nothing nada zip. I tried spraying quick start down the carbs while cranking engine and nothing. I took the plugs out ( wet ) checked for spark while wet and they lit no problem. I dried them reinstalled and still nothing. Did variations on this a couple of times, cranked it without plugs to blow anything out it seemed dry enough no major fog spraying but it was enough to wet the plugs each time. Last attempt was directly spraying quick start into the cyls, quickly putting in spark plugs, crank and not even a hiccup. Its as if there is still no spark at all.

What do you guys think I should do next?

[gotboostedvr6]

Mixed up wires on the boxes

[LakeFever]

I did check to see it was correct but I will go over it again to be sure. If it fires I will post up, if anyone else has suggestions im open to any pointers, thanks for the speedy replies guys I appreciate it.

[FORBESAUTO]

If it’s firing but not starting, I’m with recheck your wiring. Make sure wires with yellow tape from trigger are on the same switchbox with wires with yellow tape going to coils.

[FORBESAUTO]

[LakeFever]

Okay so the wiring was routed correctly. I pulled the plugs again, sprayed quick start down the holes, lit that on fire with a propane torch and heated each hole for ten seconds. Put the plugs back in and BAM she fired up like an angry bees nest. Scared the piss out of me it hit, and lit, and spun way too high for my liking so I killed it instantly. I tried to fire it again and it was very hard to start. The amount of idle arm and prime/choke/pushkeyin whatever that is on this thing is sensitive. I played around a bit had it idling well, the tell tale is weak though so is that normal like my old 7.5 and it will work better once run or is it game over for the water pump?

That aside there is another issue. That melted box I mentioned earlier that appears to have been fixed was sparking/arcing a little especially dropping down off a rev up. Im not sure what it is I will check those manuals posted earlier but I will definitely be swapping that out for new. Good thing it was dark or I dont think i would have seen it.

Anyways looking up, it was good to hear it run. Sounds meaner than I expected

[LakeFever]

That small square box with three poles on it above the sparkboxes to the left is arcing/sparking and melted a little. Any idea why?

[LakeFever]

The schematic is hard to see but I think its a terminal box is that correct? Its to the left of the starter solenoid, and above the spark boxes slightly to the left.

[FORBESAUTO]

That’s the rectifier for the charging system. Normally burning and arcing is caused by a poor connection causing excessive heat from the extra resistance. Make sure the nuts are tight. If it’s burned probably gonna have to replace it so it doesn’t cause damage to the regulator and/or stator. You can still get the rectifiers, the regulator for that style is NLA. It is replaced with one of the new style regulators from the 40 amp system, which also contains the rectifier so if you go that way, the rectifier in the picture will be eliminated.

[LakeFever]

Its definitely replacement time its melted and the fix is mickey mouse. Is it common for the regulator to crap out when these arcing is happening too or do you think id be good to go with a new rectifier?

[LakeFever]

What about that tell tale not spraying well? I had head phone style water feed on it. Time for new water pump too or will this work itself out once submersed in the lake?

[FORBESAUTO]

The old style regulators seem to hold up against voltage spikes a little better than the newer style. I personally don’t run a regulator at all on my 16 amp system, just run the rectifier. I have a lot of electronics on my boat and consume more than the 16 amp can keep up with anyway, so don’t have an overcharge problem. I used to to run the new style regulator set up and had to replace it a few times and decided simpler was better and have never looked back. Unless you have hardly no electrics on boat and require a regulator to keep voltage in check you can probably replace the rectifier and if not charging, do away with the regulator. Plus the rectifier is really cheap compared to the new style regulator set up. Here’s a link to the rectifier from pro marine. Look in same section and they also have the kit to convert to new style regulator.

http://parts.promarineusa.com/produc...0/1/1/154-6770

[FORBESAUTO]

What about that tell tale not spraying well? I had head phone style water feed on it. Time for new water pump too or will this work itself out once submersed in the lake?

Do you have a water pressure gauge? If so, make sure got good pressure. Sometimes tell tell won’t get full stream until at operating temp. If it’s been awhile since pump has been changed, not a bad idea to change it anyway

[LakeFever]

Rectifier replacement here we go! No wp gauge, I will look into adding that as I up performance. Im itching to get it in the drink and test it out so Im probably going to grab a rectifier and get it in the water this week for a test hit

Thanks for all the help Forbes!