First post for a long time skulker. So many thanks to all who have helped along the way in getting my old boat to this point. Second, my condolences to the family & friends of Don S, my experience with him was only through his posts, which were always insightful, and I am certain he will be missed here in the cyber-world, as well as in the real world.
Now to the question at hand... Boat has set for a few years due to various non-engine related issues, but I am now reviving it. After replacing oil/oil filter/fuel filter/plugs and cleaning points (they were replaced after about 5hrs use prior to going into long-term storage), the engine is running rough under 750rpm or so, and I can't get it to idle down to spec. I have a carb rebuild kit on order and am thinking that should take care of it.
However, in looking through the factory manual, there seems to be something off about the firing order information in relation to my engine. First some terminology to hopefully ease what I am going to say. (F)ront of the engine is #1 cylinder, (B)ack of the engine is #4, (I)nboard is toward the block, (O)utboard is away from the block. Service manual #1, specifications page 8-1 shows figure 3 on page 8-4 as the firing order configuration. So the rotor moves through the following positions, FI, FO, BO, BI, with the FI position being when #1 fires. My setup seems to be as in figure 1 of that page, FO, BO, BI, FI, with the FO position being when #1 fires. I have verified that the pulley timing mark is at 0deg when the rotor is pointing at FO & BI, but I have not actually checked pressure coming out of the #1 cylinder as the rotor moves from FI to FO.
So, my bottom line question is, if #1 firing position was out 90deg, there is no way this engine would be running at all, right? Or am I reading something wrong in those figures? Sorry for the lengthy post, any assistance would be appreciated.
Now to the question at hand... Boat has set for a few years due to various non-engine related issues, but I am now reviving it. After replacing oil/oil filter/fuel filter/plugs and cleaning points (they were replaced after about 5hrs use prior to going into long-term storage), the engine is running rough under 750rpm or so, and I can't get it to idle down to spec. I have a carb rebuild kit on order and am thinking that should take care of it.
However, in looking through the factory manual, there seems to be something off about the firing order information in relation to my engine. First some terminology to hopefully ease what I am going to say. (F)ront of the engine is #1 cylinder, (B)ack of the engine is #4, (I)nboard is toward the block, (O)utboard is away from the block. Service manual #1, specifications page 8-1 shows figure 3 on page 8-4 as the firing order configuration. So the rotor moves through the following positions, FI, FO, BO, BI, with the FI position being when #1 fires. My setup seems to be as in figure 1 of that page, FO, BO, BI, FI, with the FO position being when #1 fires. I have verified that the pulley timing mark is at 0deg when the rotor is pointing at FO & BI, but I have not actually checked pressure coming out of the #1 cylinder as the rotor moves from FI to FO.
So, my bottom line question is, if #1 firing position was out 90deg, there is no way this engine would be running at all, right? Or am I reading something wrong in those figures? Sorry for the lengthy post, any assistance would be appreciated.
