can't figure it out

**rock** · 08-10-2017, 12:08 PM

Guy brought me a 1993 135 with severe carnage. Rod thru block type stuff. I had an 84 2.0 that I told him I would sell him. Took 84 on trade from a member here and it is very nice. Fairly even compression and it was running when he stripped it down. I took a set of electrics off a running 2.4. Set it up and it idled kind of high so I started trying to adjust. When you hit throttle it goes up to 3000 rpm and will not go further. Classic stator failure so I put on a different stator from another motor. Same symptoms. I will not bore you with the total process but I have tried 3 stators, one new out of the box. Two triggers, one new out of the box. Three different sets of switch boxes and two different flywheels. None of this has done anything for me. Next it went to my local Mercury dealer and he questioned what I had done so far and played with it for a couple days with the same results. I have removed the carbs and they are spotless and are the correct wh29 for the motor with the correct main, idle, and vent jets. Even made sure they had correct throttle plates and the throttle shafts are not worn. Chris Carson reeds in perfect condition. Timing has been checked and re-checked. Cylinder walls are all good with new head gaskets. I did change adapter plates from a 2.5 based 2.0 to a 2.4 based 2.0. All new gaskets on carbs, and reed plate. No modules or oil injection. What the hell am I missing. All ideas, thoughts, opinions, and or observations welcome.

Rock

**luv2gofast** · 08-10-2017, 12:22 PM

WOW that's a good one! Is that 3000 under load or free rev? Did you try to pull plug wires to find out if all cyls, bank of cyls, pair of cyls or a single cyl is holding it back? Should be a clue there.

**rock** · 08-10-2017, 01:03 PM

All six firing according to timing light. Not under load and when on water had same symptoms.

Rock

**luv2gofast** · 08-10-2017, 01:32 PM

Pulling wires may still give a clue if it's fuel related. If ya don't liked to get zapped get some plug wire pliers...

**W2F a V-King** · 08-10-2017, 02:41 PM

Did you try spraying carb spray into the motor with the air silencer off? Or a squirt bottle with gas oil mix, something flammable.

Put a silencer to carbs gasket on incorrectly one time and it blocked off the vent ports

and wouldn't spin up.

Looking at your list....you at least know what it ain't!

**bullet123** · 08-10-2017, 02:51 PM

Coils breaking down at higher rpms?

**rock** · 08-10-2017, 03:14 PM

I should have explained it better. Main issue is it will not idle under 3000 nor pull past 3000. It's like it is stuck there. All linkages correct. Carbs off cam. It times fine and is set at 11 atdc and 18 btdc. Throttle plates completely closed. I thought air leak but have changed all gaskets. Fuel pump diaphragm good. Air silencer is off and fuel bowls are full. Checked enrichner and it is working correctly. I am running out of things to check. Last week I had one brought in that had a blown head gasket but they ran it anyway till the rods welded themselves to the crank. I put in a new sleeve, crank, and a couple rods and it started and idled instantly. It's not that I am a wizard or anything but it's not my first rodeo either. Absolutely dumbfounded. Thanks for the ideas.

Rock

**JAFFA** · 08-10-2017, 04:41 PM

Sounds dumb but check the green switch box wires are going to the right coils. Did a plate gasket once and coils were hanging loose when changing. In rush, stb coils went on port side etc. Ran but not well

**rock** · 08-10-2017, 05:17 PM

I've traced every wire on tis sucker.

Rock

**mach351** · 08-10-2017, 05:27 PM

The trigger moving freely? Had one once that the wiring coming from it would hang up and not let it move like it should with the throttle arm.....

**transomstand** · 08-10-2017, 06:59 PM

Start getting reeeeeal basic Heathen.

What's it take to reach 3000 rpm? Increase timing (not likely because you can see that), increase fuel/air (also not likely because without a corresponding increase in timing it will probably drown itself), or increase air only. My vote is for air only and you got a leak to find.

Bunny says don't get fancy over thinkin it.

**vnemous** · 08-10-2017, 07:07 PM

leak in gel seal?

**outasite** · 08-10-2017, 07:39 PM

My votes for case,and or end seal leakage.

**rock** · 08-10-2017, 07:40 PM

Splittin the case is about the only thing I haven't done. The rotating assembly was from a running engine but I spose it could be.
I agree with the air leak.

Rock