Timing on XP150

What is the correct timing for a 1986 Evinrude XP150?

The OMC Manual says 30*BTDC, but the carb cover says 28* BTDC.

Thanks

Re: Timing on XP150

Brian,
I have an '89 E150XP; both the manual and the air silencer say 28 BTDC for my engine. I would probably follow the shop manual, unless you know for sure that the airsilencer is original for that engine.

Re: Timing on XP150

Hmmm, maybe it did get switched. Never thought of that.

I did it based on the 28*, but maybe I should switch it and go to the 30*. I actually put it at 24* based on Joe Reeve's method.

I think I'll go back to 26* based on his method.

If it should be 30* and I have it at 28*, is that safer or more harmful?

Thanks!!

Re: Timing on XP150

Some of the XP models were setup at 30 degrees. These models had lower compression heads and still made their horsepower (in part) because of the timing. If you have original heads on the original block you are ok at the factory manual setting. Check/verify your head part numbers. I would run 93 octane, however. There are many thousands of airbox covers out there with the 28 degree timing decal-it was a common setting for many years.

Re: Timing on XP150

The timing is based on a specific set of heads with a certain spark plug, 87 octane and the fuel flow of specific carbs. If you have changed heads, cut the heads, run a different plug, run higher octane, decked the block, changed the carbs or altered the carbs in any way you need to back off the spec.

Re: Timing on XP150

Brian,
from what I understand, Joe Reeve's method may not work for an XP with the Quick Start ignition system. You may want to check in your manual for whether your ignition is Quick Start. If my understanding of this is wrong, please let me know! I'd love to use the Joe Reeves method rather than the strap-to-the-trailer-at-WOT-and-pray-out-loud method....

Re: Timing on XP150

1st, I was having trouble finding Joe's Method via search, but I did come across his email, so I sent him an email to get it. I also asked about the quick start and was told my engine shouldn't have that feature. If someone thinks I do, then I need to know. The manual doesn't seem to mention it either.

2nd, I don't think the internals of this motor had ever been touched prior to me rebuilding it and I didn't change anything except once over on the piston size(s).

My engine is E150STLCD and I believe my heads are 332545 (I grabbed that from another post of mine). Are these the lower compression heads, meaning I should have a different timing? If so, what?

It also appears the carbs are stock setup. I rebuilt them and all the orifice's were numbered the same as the parts catalog. The only thing in question on these carbs was the valve seat. The one in the kit had a different sized opening than the one on the carb(s). I didn't replace it.

I also use the plugs called for by the manual.

Re: Timing on XP150

Those should be the original heads to the XP.

Re: Timing on XP150

OK, then I should probably set it based off of 30* instead of 28*.