Vaporeon solo failure
Yesterday, I was waiting for 4 tier 3 raid eggs to hatch (all of them would hatch around the same time), hoping one of them would be a Machamp.
I was totally shocked when ALL 4 of them hatched Vaporeon! So, I went to the one which was my team colour. The boss had Aqua Tail. I had beaten this moveset twice before, with 5-7 seconds left.
I just could not beat it this time despite having 50 minutes and lots of attempts. This was my lineup (in that order for most attempts, as well as the 2 successful ones):
1: Exeggutor CP 2623 C/SoB
2: Exeggutor CP 2528 BS/SoB
3: Exeggutor CP 2506 E/SoB
4: Exeggutor CP 2433 E/SoB
5: Jolteon CP 2346 TS/Tb
6: Dragonite CP 3043 DT/O
7: Dragonite CP 3052 DT/O (I used either one of the Dragonites in each attempt, except for one where I used both)
On some attempts, I put the BS Egg first before the C one. I didn't notice any difference.
On one attempt, I removed the 4th Egg and put both Dragonites at the last 2 slots. Surprisingly, this was the closest attempt. The screenshot of this attempt is below. (I timed out on the first Dragonite)
What did I do wrong in this attempt?

Answers
No dodging against Vaporeon unless there is a possibility to squeeze in an extra SoB! I also tried with an all Exeggutor team yesterday and failed too. For me it is iPhone 6 with a lot of lagging that is the problem. 6 Lvl 34 Exeggutor will make in 155 secs in theory, so just small issues with lag etc will make you fail, and most only have 1-2 at lvl 34+ which makes it more difficult. Raikou is the solution (and a new phone)
Luck and lag I believe. I have solo'd vaporeon successfully a few times on each movesets including hydro pump but my success rate is still very very far from 100%. I use 4 solar beam exeggutors as well all level 32 + a level 30 raikou Ts/Wc.
Aqua tail has the biggest luck factor I think. Every single time I get my 3rd solar beam and It doesnt count because vaporeon spammed his aqua tail right before I think it's probably best to quit rigth away and retry.
I think your team is ok but on the brink of being too weak for vaporeon, meaning that you might have to rely on luck with the boss cm behaviour to beat him. I reckon your four solarbeamers are the key to beating vaporeon. If some of them survive just a tad longer because the boss spams less cms, this might make all the difference. Frankly, I am surprised that you had so much time left in your other attempts. My vape team is a bit stronger than yours and for me it was always closer than that. Again, boss cm timing can make all the difference, I guess.
I have the following suggestions:
1. Use a Fast TM to change the fast move to BS on each of the three Exeggutors that do not have BS. The analysis I have read on Game Press' page about Exeggutor is that BS/SoB is the best move set for the Exeggutor v. Vaporean matchup.
2. Examine your Exeggutors carefully to determine each one's Attack IV and Level and then use this spreadsheet to determine to what Level you need to boost one or more of the Exeggutors to hit that Exeggutor's breakpoint for Vaporean and then level one or more of the Vaporeans up as needed.
https://docs.google.com/spreadsheets/d/1bBaDEb4nIMYQc_ChN053kM9ToN734lrOOPH5sS7POKk/edit#gid=124395849
Try #1 above first if you have a decent number of Fast TMs to throw at this problem. The nice aspect of this is that it does not cost any stardust.
2 above is certain to help, but likely will cost some stardust. Using the spreadsheet will guide you on how best to use that stardust.