mercury 200 xr6 bogs down at 2000 to 2500 rpm under load

**Jimmopotomus** · 06-08-2021, 08:12 AM

Trigger and stator in with no problems, just gotta get it to the shop for synch and timing before I can test it. Hoping for the best.

**SPIDERMONKEY** · 06-17-2021, 01:09 AM

Originally Posted by Jimmopotomus

Trigger and stator in with no problems, just gotta get it to the shop for synch and timing before I can test it. Hoping for the best.

How did you make out? Inquiring minds would like to know

**Jimmopotomus** · 06-18-2021, 08:46 PM

I went to the coast for the week and just got back today. Getting the timing and synch done on Monday then test run on Tuesday hopefully.
Fingers crossed. I’m thinking on towing it from Austin to Florida next summer (Okeechobie) is on my bucket list.

**Jimmopotomus** · 06-21-2021, 12:35 PM

A new chapter to the saga of this boat. Took it to shop today and explained what I had done so far and asked about next steps other than the timing and synch. While there we did a compression test and #6 is at 100 while all others were 120. Cylinder walls are scored etc. I am just going to have them replace the power head and synch it all back up. It’s my safest option as far as I know. If anyone has further advice I would appreciate it.
Thanks

**bullet123** · 06-21-2021, 12:41 PM

In the first post you said compression was in spec. What happened in the mean time?

**Jimmopotomus** · 06-21-2021, 12:54 PM

The 1st shop I took it too when I bought it indicated that it was slightly low and that they fixed the problem by decarbing the valves. I took them at their word. ( rookie mistake)
Valuable lesson learned, this shop brought me back while they tested it and showed me as they scoped it. Mechanic believes a reed in the bottom carb broke and got into the #6 cylinder.

**25two.stroke** · 06-21-2021, 12:57 PM

"decarbing valves" ??? what is that?

**Jimmopotomus** · 06-21-2021, 01:14 PM

The way I understood it was that carbon buildup was keeping one of the intake or exhaust valves from closing all the way thus creating lower compression. As stated in my 1st post I am by no means a mechanic so I took him at his word.
when I look at what I just wrote I feel a little stupid, but lesson learned none the less. Just hope new power head makes it run as intended.

**25two.stroke** · 06-21-2021, 01:19 PM

Yeah there are no valves in a 2 stroke that can get carboned up. In a 4 stroke engine, yes. Not in a 2 stroke.

Did anyone ever pull the carbs look at the reeds? Your initial problems do not indicate a reed problem. If the reeds on #6 were busted it would not idle, be hard starting and probably lean pop/sneeze. #6 having scoring is classic of EFI motors from that era. They always like to burn #6 more than any other cylinder for some reason (in my experience). Do you know if the motor was ever an EFI converted to carbs? Also, if the jetting was wrong or plugged up it could score that cylinder without "eating" anything metal.

If you still have that idle stabilizer module I would start there. Your original issue sounds electrical. Bad stator or shorted ignition stabilizer sending your stator power to ground.

**Smalltownbassin** · 06-21-2021, 02:00 PM

Im with 25two.stroke on this one. Even with one hole at 100psi you still have life left in it. You've already bought new parts. Why not fix it and run it until she gives up before repowering?

**25two.stroke** · 06-21-2021, 02:12 PM

Was the xr6 2.5 steel or was that just the 2.0 xr2 that was steel? I honestly never have seen a carb xr6, so I don't know what funny stuff they did with them. If its steel then a simple quick hone and a piston could fix it up.

**Smalltownbassin** · 06-21-2021, 02:33 PM

Originally Posted by 25two.stroke

Was the xr6 2.5 steel or was that just the 2.0 xr2 that was steel? I honestly never have seen a carb xr6, so I don't know what funny stuff they did with them. If its steel then a simple quick hone and a piston could fix it up.

Steel bore in the XR6 2.5L 150. That 200 XR6 badging is what confuses me. The real XR6 is a carbed 2.5L 150.

**tlwjkw** · 06-21-2021, 02:37 PM

only one kind of xr6... its a 2.5 carb steel sleeve 150 ....

**tlwjkw** · 06-21-2021, 02:38 PM

tha 200 XR6 badging is a "nitro" promotion thing only..

**bullet123** · 06-22-2021, 04:25 AM

Originally Posted by Jimmopotomus

The way I understood it was that carbon buildup was keeping one of the intake or exhaust valves from closing all the way thus creating lower compression. As stated in my 1st post I am by no means a mechanic so I took him at his word.
when I look at what I just wrote I feel a little stupid, but lesson learned none the less. Just hope new power head makes it run as intended.

I have regained compression by decarbing a motor. Basically soak cylinders with sea foam or something similar. removes carbon buildup. I hope this new place you are dealing with isn't in this to just sell you a powerhead. Are you keeping old powerhead or trading it in?