Weak flush Augusta by Toto with Master Mark IV

[Plubit]

I have an old Augusta by Toto 1.6 Gpf toilet. I couldn't find much on the toilet so I'm guessing it was one of the early 1.6 Gpf toilets. The toilet has a Master Mark IV refill valve installed with no tube installed between the refill tube nipple and the tank's refill tube. There is no water flow from the refill nipple as it appears to be closed off. Would a lack of water into the tank's refill tube contribute to a weak flush?

In the following post another user describes a similar issue with the Mark IV having a closed off refill nipple. Is it alright to drill this out? I couldn't locate any directions mentioning this step, however, I did find an Amazon review that mentioned drilling it out.

https://terrylove.com/forums/index.php?threads/coast-master-mark-iv-refill-tube.90808/

Thanks!

 

[Terry]

How about a picture of the toilet, and there should be a number inside the tank starting with CST
Augusta is not a model, it's a line, which could be most anything.

 

[Sponsor]

 

[Plubit]

How about a picture of the toilet, and there should be a number inside the tank starting with CST
Augusta is not a model, it's a line, which could be most anything.

I can't post a photo at the moment, but there is no number starting with "CST". The number inside the tank appears to be ST70 (there may be another character after, but it is not clear). Further to the right of that is 2118:1403.

 

[Terry]

Perhaps CST703, one of the first ones they produced. More of a builder grade toilet.
The fill valve didn't have a fill valve to refill the bowl on those. And yes, the ballcock with the arm and ball.
If it doesn't flush really well, I'm not surprised.

https://www.totousa.com/filemanager_uploads/product_assets/SpecSheet/SS-00240_CST703_DISC.pdf

https://terrylove.com/forums/index.php?threads/toto-cst703-toilet-not-clearing.34276/

 

[Plubit]

Would water from the fill valve into the refill tube improve the flush at all? I'm tempted to drill the closed off refill nipple and add a refill tube, but still cannot find solid information on that being an option. I also don't want to waste the time if it isn't going to improve the flush? Is the only possible improvement to clean the fill holes under the rim of the toilet?