35 HP Briggs Rattling / Power Loss

[juggernaut]

When I put a heavy load on my 35hp Briggs, I get a rattling sound and loss of power, the engine also seems to get excessively hot . Has anyone had this kind of problem and what was the result ?

[6X6]

Well it would sound like it's pre-ignition/detonation? What is the compression ratio and what octane are you running? Be sure you're using the recommended minimum octane (Preferably higher, and I'd start by trying fresh 93 to see if that does it) and the proper plug, too hot will cause pre-ignition. So will carbon buildup, after plug/fuel, I'd check that. ATF in the Carb works, Racerone3 mentioned it, I've now done it and it's not bad at all, plus it fogs the mosquitos and nosy neighbors (Ask Racerone3 if you want to try it{if you find you have significant carbon buildup}, I've done it but not a lot, and don't want you to hurt you're engine cause I word something wrong). And of course, make sure the timing is set properly if all else checks out.
I don't know how to time that engine off the top of my head, sorry.

[Model Citizen]

What kind of car do you have this in? Is the motor getting enough air? Does it have an oil cooler? If you put it under a load & it gets too hot, it's probably just letting you know that it needs more help.

Bridget