Should I put two loosely related results into one paper? I'm working on a problem A, and recently have two small results:


The first result is using technique X for A1, which is a particular instance of A. A1 is a long-term problem, but nobody has used X for it before, and I achieve slightly better performance with it. In other words, it is only an incremental result.
The second one is solving A2 using technique Y. A2 is totally new problem that nobody has touched before. However, the method is extremely expensive, and only works on toy programs.


Since both two results have clear weaknesses, and we don't know how to improve them, my advisor is suggesting me to put the two results in one paper to submit to a major conference, since each of them is not enough contribution. 

It is only a suggestion and I can decide whether to do it, there is no problem with the advisor. I'm only confused if it is a good idea to do so. My concerns are:


A1 and A2 are just loosely related. It is difficult to tell a story that connects these two problems.
The first method is only applicable for A1, the second method is only applicable for A2, while they are different instances of the problem A. Putting them together poses another weakness: the usability of each method.


The other option is of course: submitting them separately to lesser conferences. We only want to do this if the first option is not promising.

Some context: my advisor is a leading expert on X and Y, but knows very little about A (but wants to explore). On the other hand, I did my PhD on A, and only have some minimal background on X and Y. I'm a new postdoc, hired to work on A using the tools for X and Y that my advisor had developed. Therefore, none of us are 100% sure about what to do in this situation.
Just reading and trying to understand your question made my head spin, most likely due to use of generalization (X, Y, A1, A2), but not only that. Therefore, IMHO, the safest approach to solving this dilemma is to separate results into two papers. The rationale for this approach is the following.


Each paper would have a clear and, thus, easily understandable scope, goals, methodology, results and their interpretation. That would significantly improve readability and overall quality of each paper and chances to form a positive impression.
Since the problems A1 and A2 are "loosely related", shoving them into a single research study simply doesn't make sense from an architectural / logistical / layout perspective. It would be very difficult to present two sub-studies in a synergistic manner ("tell a story", as you put it).
Based on the above-mentioned points, I don't see how combining the studies would make the resulting "study" of higher quality, thus, warranting a publication in a more major conference. Quite the opposite most likely would be true (due to coherence and, thus, readability issues).
Your advisor's recommendation in regard to improving your work is quite strange, to say the least. It is based on the assumption that combining two studies of different scope/topic with weaknesses would make the resulting "study" less weak. If anything, it would make it even weaker, since weakness is one of multitude of characteristics, exhibiting additive properties.