Merc XR6 - Service Bulletin 91-35

[gflattmann]

Hi, I've been working on getting my 79' predictor with a 94' xr6 sea worthy again, she has been sitting for the last few years.... The last time I ran it, she would bog down when transitioning to high rpm. I figured it was either dirty carbs or something electrical. So several years later I'm finally able to start working on her again. I've completely broken down the carbs and rebuilt them, removed the oil injection, and replaced the battery. It's starts great and seems to idle good as well, although at high rpm it still kind of sound like its missing.... this is all in my drive. I just visually checked all the electrical connections and everything appeared to be fine. I decided to go read the electrical/ignitition info in the engine manual and found a reference to Service Bulletin 91-35... I can't seem to find clear information on the bulletin. What I have found indicates to remove one of the modules and adjust the timing.

Anyone know about this? Is it one module or two modules that need removing? what timing to adjust? will this possibly solve the bogging down at high rpm?

 

[Jimway]

That bulletin was or ended up later being to delete the idle stabilizer all together and go with 22 degrees on the timing? if I remember correctly. It seems like the xr2,3,4, and 6 had the idle stabilizer thingy. I believe it worked by changing the resistance at the bias wires from the power packs to advance or retard timing as necessary. I'm assuming you have a new set of plugs on there. Check high speed side of stator output. Extremely important to make sure that you don't run engine lean.